micro process gas chromatograph ( pgc) analyses … solutions and products bv micro process gas...

Analytical Solutions and Products BV

micro Process Gas Chromatograph (PGC) analyses with Sample Conditioning

by drs ing Tim Lenior

Analytical Solutions and Products BV July, 17 2012

Analytical Solutions and Products BV rev1a

Contents:

1 Introduction to process analyses .......................................................................... 5

1.1 Micro Process Gas Chromatography (µPGC) ............................................................ 5

1.2 Research and theoretical aspects (2) ......................................................................... 6 1.2.1 µGC and narrow – medium bore columns ............................................................................... 6 1.2.2 Micro-Injection (2) .................................................................................................................. 12 1.2.3 The µTCD and the detection limit (4) (6) (2) .......................................................................... 12 1.2.4 The minimum detectable amount (2) ..................................................................................... 15 1.2.5 The µGCs discussed and used for the LNG Probe tests ...................................................... 16 1.2.6 Description/explanation of the Agilent 490-GC µGC: ............................................................ 16

1.3 Applications (8) (9) ..................................................................................................... 19 1.3.1 Natural gas & Liquified Natural Gas LNG .............................................................................. 19 1.3.2 RGA, Cokes gas Analyses .................................................................................................... 20 1.3.3 Sulfur analyses (9) (14) ......................................................................................................... 20 1.3.4 Syngas analyses (18) ............................................................................................................ 23 1.3.5 Biogas & Biomass analyses .................................................................................................. 23 1.3.6 Environmental analyses (20) ................................................................................................. 24

2 From process sample to process control ........................................................... 26

2.1 The essential steps in process analyses ................................................................. 27

3 Sample handling and integration back ground information .............................. 28 3.1.1 Further developments in sample handling (NeSSI™) (22).................................................... 30 3.1.2 Integration of equipment in process plants a slim analyser package (aSAP) (9) .................. 31

4 Discussions and Conclusions ............................................................................. 32

4.1 Further discussion for process analysis .................................................................. 32

5 References ............................................................................................................. 34


List of figures: Figure 1: plate heights vs carrier gas velocity (2) .......................................................................................... 6 Figure 2: analysis time vs column ID (2) ....................................................................................................... 7 Figure 3: plate hight equation & the van Deemter H vs u curve (2) .............................................................. 8 Figure 4: efficiency packed vs. capillary column (2) ...................................................................................... 9 Figure 5: plot of time H/u vs required plate number (5) ................................................................................ 9 Figure 6: carrier gas velocity u vs column ID (2) ......................................................................................... 10 Figure 7: PLOT Columns application Areas (2) .......................................................................................... 10 Figure 8: adsorption and absorption GC (2) ................................................................................................ 11 Figure 9: thermal conductivity of gases (2) ................................................................................................. 12 Figure 10: Thermal Conductivity Detector (TCD), the Wheatstone Bridge configuration ........................... 13 Figure 11: plot of minimum detectable concentration, Co, against column diameter dc , for n-C7 on a FID and µTCD (6) ............................................................................................................................................... 14 Figure 12: column diameter speed and detection limit (2) at the same injection volume (2) ...................... 15 Figure 14: Agilent 490-GC micro-gaschromatographic system .................................................................. 16 Figure 13: Agilent 490-GC µGC system ...................................................................................................... 16 Figure 15: sample & inject on the chip injector ........................................................................................... 17 Figure 16: etch pattern of the micro machined injector (7) ......................................................................... 17 Figure 17: portable Zone 2 uGC courtesy of ASaP BV ............................................................................... 18 Figure 18: stationary process uGC for ATEX Zone 1. courtesy of ASaP BV .............................................. 18 Figure 19 New LNG probe design ............................................................................................................... 19 Figure 20: Cokes Gas Analyses .................................................................................................................. 20 Figure 21: Lemon yellow Sulphur crystals .................................................................................................. 20 Figure 22: Emissions of SO2 in 25 European countries in 2004 . ............................................................... 21 Figure 25: Stability and step test for 3 to 0.5ppm H2S on a µTCD .............................................................. 22 Figure 23: Sulphur melts to a blood-red liquid. When burned, it emits a blue flame and forms SO2 from: S + O2 -> SO2 .................................................................................................................................................. 22 Figure 24: 5.8ppmv H2S LOQ 0.5 ppmv on a µTCD ................................................................................... 22 Figure 26: ASaP standalone Biogas Analyser ............................................................................................ 23 Figure 27: Column 4m CPSil5 CB ............................................................................................................... 24 Figure 28: Column 10m WAX 52................................................................................................................. 24 Figure 29: the steps from process sample to process control .................................................................... 26 Figure 30: from process sample to process control, the P&ID .................................................................... 27 Figure 31 Genie Retractable Probe Regulator Model GPR with integrated membrane (courtesy of Genie inc.). ............................................................................................................................................................. 29 Figure 32: standardized building block for the NeSSI platform (courtesy of Circor Tech) .......................... 30 Figure 33: a sample handling system on the NeSSI platform (courtesy Circor Tech) ............................... 30 Figure 34: all steps from sample take-off to analysis integrated in one 3D probe (courtesy of EIF) .......... 31 Figure 35: on pipeline installation including side platform ........................................................................... 31 Figure 36: a Slim Analyser Package (aSAP), the back wall is transparent for illustration .......................... 31 Figure 37 a µGC integrated into a Process (ATEX) certified µPGC and an aSAP analyser package ....... 32


List of tables Table 1: sample capacity and film thickness (2) ......................................................................................... 11 Table 2: thermal conductivities of some components and carrier gas He .................................................. 18 Table 3: Repeatability for 1-3ppm H2S on a µTCD (17) .............................................................................. 22 Table 4 Micro GC Column Modules ............................................................................................................ 25


1 Introduction to process analyses In a history overview of Gas Chromatography (GC) in the petrochemical industry (1) it was stated that, after GC was introduced by James and Martin in 1952, GC was well established within the petrochemical industry already in 1956. Since that time part of the GC has evolved from the laboratory into the process environment. Analytical techniques and in particular GCs are used in process plants to determine product quality & yield and GC is used as a guarding technique to protect essential process operations. Such as the protection of catalyst in a reactor against contaminants. Industrial processes are operated by process control systems. The process control system operates based on the measurement of physical properties and composition of the product. The composition of the product is mainly determined in the laboratory. Laboratory analyses are done within hours. Such measurement timeframe can have a negative impact on the process plant’s throughput and product quality. An upset condition at the front may results in an off-spec condition at the output when not quickly corrected. Therefore fast analyses are required. Some of these analyses are performed on-line in the plant at different critical points in the process. This will speed up the measurement and the operation of the plant, resulting in a better control of product specification. Installing on-line analytical instruments will also minimize the errors that are introduced when taking manual samples. Eventually on-line process analyses will result in the increase in the plant’s product yield and in the return on investment of the analytical system. It is not a matter of how much an on-line analytical system cost but how much money the implementation of an on-line process analyses can make, by the product quality and yield improvement! 1.1 Micro Process Gas Chromatography (µPGC) Micro Gas Chromatography (µGC) is a development that can be used for fast process analyses. µGCs are fast due to the use of narrow and medium-bore columns. Second size and separation power of µGCs allows it to be used for fast analysis and integration in a process plant. Moreover, for a number of practical reasons it is an advantage to miniaturize the equipment for process analysis. Those practical advantages are:

close mounting to the sample take-off point

lower amounts of sample gas needed

lower transfer times of the samples

shorter delay times for analyser results

low energy and utility consumptions

easier explosion proof (ATEX, CSA) integration

increased reliability (24/7) operation

increased precision and accuracy Apart from the practical aspects of µGC technology this chapter will focus on the theoretical aspects of µGC technology and in particular Micro Process Gas Chromatography (µPGC).


1.2 Research and theoretical aspects (2) In Chapter 1.1 the advantages of µGC technology was discussed, here the theoretical background about the µGC technology will be discussed. This paragraph describes the background of narrow and medium bore columns, micro-injector and micro thermal conductivity detector (µTCD). 1.2.1 µGC and narrow – medium bore columns GC is a commonly used technique for compositional gas analysis. These measurements generally take place in the laboratory. Analysis times of 10 minutes to one hour is normal. In a process environment much faster analyses are required for the purpose of control of the subsequent processes. Analysis times of 30 seconds to a few minutes are required for process analysis. The advantage of µGC are, besides the reduction in size of the instrument, speed and their detection limits. µGC technology uses narrow to medium bore capillary and micro packed columns. These columns in combination with an appropriate detector results in faster analysis and lower detection limits. This was described by Thijssen et al (3) in 1987 and Cramers et al in 1999 (4). It is an improvement compared to conventional GC techniques. Theory behind this describes (4) that the reduction of the characteristic diameter, being the inside of the column diameter for open tubular columns and the particle size for packed columns, is the best approach to increase the separation speed in gas chromatography (Figure 2). Hydrogen and Helium carrier are the best choice for higher carrier gas velocities. Lowest plate height (HETP) is achieved for N2 in the optimum for the carrier gas velocity but when increasing the carrier velocity through the column Helium and Hydrogen give lower plate heights as can be seen in below figure.

Figure 1: plate heights vs carrier gas velocity (2)


Reduction of the inside column diameter results in a reduction in analyses time as displayed in below figure.

Figure 2: analysis time vs column ID (2)

A few reasons of the reduction of the total analysis time as described by (4) are: 1) Reduction of the characteristic diameter being the inside column diameter for open

tubular columns and the size of particles for packed columns is the best approach. The equilibrium between mobile and stationary phase is faster for narrow bore columns due to the relative distance for the molecules to get from the mobile to stationary phase. Analysis time can be reduced proportional to characteristic particle diameter dp

2 and

column diameter dc2 for respectively packed r capillary columns for p=1barg and linear

proportional to dp or dc for p>>1barg. 2) Also the film thickness is of some influence. In thin-film the Cs-term in the simplified Golay

equation (Figure 4) can be neglected.(e.g. df=0.4µm) 3) The influence of carrier gas type due to the diffusion coefficient and carrier gas viscosity

is 60% worse for He compared to H2 (smaller molecule H2 compared to He). H2 is therefore the best choice. (for safety reasons He is often chosen in process analyses)

4) Temperature programming, higher temperature gives lower retention (10-15 C higher =2x lower retention). Temperature programming should be ultra fast for narrow bore columns.

5) Multiple capillary columns : 919 coated capillaries ID40 um 1m length, high sample capacity, fast due to the 919 parallel capillary columns. e.g. aromatics up to o-xylene in 0.8 minutes.


The van Deemter equation expresses the relation between the plate height (H) and the gas velocity through the column (u).

Figure 3: plate hight equation & the van Deemter H vs u curve (2)

H = HETP (plate height)

A = eddy diffusion term

B = longitudinal diffusion term

u = linear gas velocity

C = resistance to mass transfer coefficient The terms A, B and C will influence the plate height and eventually the separation efficiency Nth. For narrow and medium bore columns in respect to wide bore or mega bore columns:

A is smaller due to relative smaller particles in packed columns.

B/u is smaller because the relative smaller travel distance of the molecules.

C is relative smaller due to the smaller relative distance of the molecules from the mobile to the stationary phase.

For thin films the Cs term can be neglected and consequently the plate height will decrease


For capillary columns the A term in the van Deemter equation, representing the column packing flow pattern will disappear due to the absence of column particles.

Figure 4: efficiency packed vs. capillary column (2)

Ultra narrow bore columns with diameters < 100 µm are not advised, because they generate high pressure drops and have very limited loading capacity. An alternative way of presenting the van Deemter equation as proposed by (5) is the time equivalent to a theoretical plate (TETP) as displayed in below figure. The curves for different particle size, or column diameter are displayed in the figure and the required plate number in the shortest possible time can be obtained.

Figure 5: plot of time H/u vs required plate number (5)


Carrier gas flows through narrow- and medium bore columns are increased as the column diameter decreases.

Figure 6: carrier gas velocity u vs column ID (2)

This has a positive effect on the longitudinal diffusion term B/u and negative effect on the C*u term. The sample capacity is reduced proportional to dc

3 for narrow bore open tubular columns (4) (with dc the

column diameter). Therefore the selection of columns with larger diameter (medium bore) will have a positive effect on sample capacity and the minimum detectable quantity. The columns used by Agilent as described in 1.2.6 consisted of a Pora PLOT Q (PPQ) column .Porous Layer Open Tubular (PLOT) columns are open tubular columns coated with a layer of solid porous material on the inside column wall.

Figure 7: PLOT Columns application Areas (2)

Porous polymers are prepared by the copolymerization of styrene and divinylbenzene or other related monomers. The silicon chip column consists of etched channels with a size of 0.3mmx550mm packed with carbon spheres of 1.3nm.


Other columns used by Agilent as described in 1.2.6 consists of a non-polar CPSil5 liquid phase (df=5µm) Also the sample capacity will increase with the column’s liquid phase film thickness (ref. Table 1). Table 1: sample capacity and film thickness (2)

Chromatography is a physical method of separation in which the components to be separated are distributed between two phases, one of which is stationary (stationary phase) while the other (the mobile phase) moves in a definite direction. If the stationary phase is a liquid phase the analyte molecules must dissolve in that liquid stationary phase and their separation is based on absorption . For the PLOT and carbosphere column type, separation is based on the adsorption of analyte molecules on a solid stationary phase.

Figure 8: adsorption and absorption GC (2)

Sample capacity of capillary columns (in ng per component) ID (mm) 0.12 μm 0.40 μm 1.2 μm 2.0 μm 5.0 μm

0.15 1 - 10 3 – 30 10 - 100 - -

0.25 2 - 50 6 - 150 20- 500 30 - 800 -

0.32 5 - 100 15 - 400 50 - 1000 80 - 1500 -

0.53 - - 50 - 1200 100 - 2000 200 - 5000


1.2.2 Micro-Injection (2) To minimize the contribution of the input band-width (Agilentce) to total band-broadening, the injected sample plug has to be narrow in comparison to the total chromatographic band broadening. In case of faster analyses the residence time of the components in the column is reduced. This results in a reduced chromatographic zone widening (i.e. the peak widths σw are reduced). Injection hence becomes more critical. This is especially true for isothermal analyses. In temperature programmed separations zone focusing will occur in the column inlet. The theoretical value for the contribution of a plug injection to band-broadening (isothermal column operation) is given by (6):

where w is the width of the injected plug. Extreme small injection band-widths (σi) are required for very fast analyses on short narrow bore columns are approximately 1-3 ms (6). For the narrow bore option for fast GC the injection band-width is critical. It is for this reason that the development of injection systems compatible for narrow bore GC has received considerable attention in literature. For narrow and medium bore columns, for the µGCs used in this paper, the injection time frame is between 10-100ms. In two of the µGCs described in this paper a chip injector was used (explained in more detail in paragraph 1.2.6). Decreasing the injector volume could result in discrimination in the injector due to differences in viscosity of the sample components in the injector . 1.2.3 The µTCD and the detection limit (4) (6) (2) The thermal conductivity detector (TCD) is a universal detector based on the measurement of the thermal conductivity of a gas. The TCD measures the difference in heat conductivity between pure carrier gas and carrier gas containing sample components. The core of the TCD is a filament, a thin wire often made of tungsten, platinum or nickel. Since the resistance of this filament is dependent on its temperature, a change in temperature will result in a change in resistance. This change can be detected electronically. The thermal conductivity of the carrier gas and the analyte influence the peak signal. If the conductivity of the carrier gas is higher than that of the analyte, this results in a positive peak. The bigger the difference in conductivity of analyte and carrier gas, the better the heat transfer and results.

Figure 9: thermal conductivity of gases (2)


Detection principle:

A TCD usually has a double channel system. Pure carrier gas flows through one channel, the carrier gas eluting from the column containing the sample components flows through the other channel.

Electrically heated filaments in each channel are cooled by the carrier gas. The amount of heat loss is a function of the thermal conductivity of the gas flowing through the cell.

Both resistance filaments are part of a Wheatstone bridge. The bridge is in equilibrium if the composition of the gases is the same. The composition of the gas flowing through the reference cell does not change.

A sample component passing the detector will change the composition of the gas. This results in a change in conductivity which, in turn will distort the balance. The resulting signal will be passed to the data recording system.

The detector has the highest sensitivity when the difference in thermal conductivity between the carrier gas and the sample components is large. This is mostly the case with the lighter carrier gases, such as hydrogen and helium (the exception is when He and H2 need to be measured).

Figure 10: Thermal Conductivity Detector (TCD), the Wheatstone Bridge configuration

The µTCD is a solid state detector (SSD) it consist of 4 silicon micro machined air bridges (two each suspended in discrete parallel gas flow channels) coated with a metal filament, which, is heated. These are arranged in a wheatstone bridge configuration. Its volume is only 200nl. Its dynamic linear response spans 6 decades covering a concentration area from 1 ppmv to 100%v.

http://upload.wikimedia.org/wikipedia/commons/c/cb/Thermal_Conductivity_Detector_1.svg


The µTCD’s concentration limit can exceed that of the Flame Ionisation Detector (FID).

Figure 11: plot of minimum detectable concentration, Co, against column diameter dc , for n-C7 on a FID and µTCD (6)

From this plot it follows that for column diameters below 135µm the application of the µTCD becomes increasingly advantageous in comparison with the FID (6). Reduction of column diameter requires a reduction of the total band-width (Agilentce) σt (σt

2 = σi

2 + σc

2 + σd

2 with i for injector, c for column and d

for detector). For the detector the band broadening depends on detector volume and flow. Reducing the column diameter results in a reduction of the allowed detection volume.


1.2.4 The minimum detectable amount (2) The minimum detectable amount (Q0), i.e. the lowest quantity of solute that can be distinguished from the noise, is given by:

Where Rn is the detector noise, S the detector sensitivity, σt is the total band-width and Fd the total flow through the detector. The minimum detectable amount is favoured by a reduction of the inner diameter (The minimum detectable amount is proportional to the column diameter, Leclercq and Cramers, 1998) and basically by any other method that results in faster analysis. This is caused by the decrease of σt when the analysis time is reduced. The minimum detectable concentration on the other hand however, is not always improved when methods for faster chromatography are implemented. The injection volume might have to be reduced to avoid an excessive contribution of the injection to the overall peak width resulting in higher detection limits. Whereas this effect is marginal for most of the options for faster analysis, the minimum detectable concentration decreases dramatically when working with columns with a reduced inner diameter. Narrow bore columns therefore are not suitable for trace analyses. Also detectors have to be very sensitive to detect the low quantities eluting from a narrow bore column.

Figure 12: column diameter speed and detection limit (2) at the same injection volume (2)

The time constant of a detector (e.g. effects of resistance and capacitance in the detector electronics)

will contribute to peak broadening and noise. Increasing by digital filtering will reduce noise and will have a positive effect on the detection limit (6). The peak width and time constant of a detector must be matched. A relative too fast detector may introduce unwanted noise while a relative too slow detector could result in peak deformation. For narrow bore columns the time constant for a detector should be relative small (fast enough detector and electronics) in comparison to a detector for normal bore columns in order to follow the fast chromatography.


1.2.5 The µGCs discussed and used for the LNG Probe tests The µGC further discussed as used process µGCs the Agilent µGC 490-GC 1.2.6 Description/explanation of the Agilent 490-GC µGC: Agilent Inc. is a company supplying analytical laboratory equipment. One of their products is the 490-GC µGC. It is the 4

th generation of µGC products which was first developed in the 1970s. The µGCs consists

of an injector, column and a detector installed in different small temperature controlled compartments. The unit uses precisely electronic pressure controlled carrier gas to run the injected sample gas of interest through the analytical column. The system can be configured of 1 – 4 channels. Each channel consist of a carrier pressure controller and a module which holds the injector, column and detector. Furthermore the instrument consists of a set of electronics and a computer in order to automatically control the different parts.

Figure 14: Agilent 490-GC micro-gaschromatographic system

Injector

Pre - column Analytical column µTCD Pre - column Analytical column µTCD

injector

Analytical System

Sample in

Sample out

Carrier Bottle or

bombe in fieldcase

Carrier in

Reference in

column in

Backflush vent

column flow

Reference flow

- TCD - detector

heated

GC COLUMN MICRO TCD CHIP

INJECTOR MICRO EGC

Heated to 110C Heated to 180C

Heated to 110C

Injector Injector

Pre - column Analytical column µTCD Pre - column Analytical column µTCD

injector

Analytical System

Sample in

Sample out

Carrier Bottle or

bombe in fieldcase

Carrier in

Reference in

column in

Backflush vent

column flow

Reference flow

- TCD - detector

heated

GC COLUMN

GC COLUMN MICRO TCD MICRO TCD CHIP

INJECTOR CHIP

INJECTOR MICRO EGC MICRO EGC

Figure 13: Agilent 490-GC µGC system

http://www.chem.agilent.com/en-US/products-services/Instruments-Systems/Gas-Chromatography/Column-Modules/Pages/default.aspx

http://www.chem.agilent.com/en-US/products-services/Instruments-Systems/Gas-Chromatography/490-Micro-GC/Pages/default.aspx


In the column, which is isothermally controlled, the injected sample gas is separated into its individual components based on their order of boiling point (non-polar columns), polarity (polar-columns), or molecular size (mol-sieves columns). The columns used are narrow (0.15mm) and medium bore columns (0.32mm). As displayed in the above diagram the analytical system also features a pre-column. This pre-column provides the functionality to pre-separate the sample. This is done to allow only the components of interest to flow into the analytical column, thus speeding up the system. But also to prevent the analytical column to be contaminated with the components of non interest. e.g. the protection of a mol-sieves column from the components CO2 and H2O. Those components would drastically decrease the separation of the other permanent gasses as N2, O2 and Ar. CO2 and H2O will fill up the pores of the material and will consequently decrease the separation power of the total column since the molecules of Ar, O2 and N2 cannot penetrate the pores anymore and will flow un-retained through the column without separation. Other µGC manufactures use different approaches to overcome this problem (e.g. by temperature programming).

Figure 15: sample & inject on the chip injector

Figure 16: etch pattern of the micro machined injector (7)

The carrier gas helium is often chosen. Helium is second best after H2 for high speed analysis (HETP lowest at high speeds) but has the advantage being nonflammable. It is a non-flammable inert gas which will transport the separated and measured components through the analytical column. At the outlet of the column the carrier gas, together with the separated components, will elute into a micro thermal conductivity detector (µTCD) detector . At this stage the components are measured, based on their difference in thermal conductivity with respect to the carrier gas (again He is second best after H2 in conductivity), and quantified measuring their area as it is digitized. The µTCD is a universal detector and will therefore measure all eluted components. The µTCD (ref. paragraph 1.2.3 for theoretical aspects) has a volume of 200nl and a limited quantity of detection of one to a few parts per million (ppm). The system can be equipped with a second detector in series with the µTCD to analyse the components to a relatively


much lower limit of quantification (LOQ). However, this detector is a selective detector and is limited in determining all components. A combination of the two detectors may produce the required detection results. This detector will be used and further explained in paragraph Fout! Verwijzingsbron niet gevonden.. Table 2: thermal conductivities of some components and carrier gas He

Thermal conductivities λ @ 1.013 bar, 0°C

Component λ [mW/mK] delta λ vs He

Helium 142.64 0

CH4 32.81 109.83

CO2 14.65 127.99

H2S 12.98 129.66 Integration on a process instrumentation platform: Two examples of the integration of the Agilent µGC in a portable Zone 2 and Stationary Zone 1 cabinet for on-line installation is displayed below.

Figure 17: portable Zone 2 uGC courtesy of ASaP BV

Figure 18: stationary process uGC for ATEX Zone 1. courtesy of ASaP BV


1.3 Applications (8) (9) A number of applications can be addressed as interesting in the area of Process Gaschromatography. Where speed and complexibility is an advantage over conventional equipment. The process environment uses a broad range of analytical equipment and in particular the Gaschromatograph. Due to its general employability and compositional analyses it is a preferred technique in this area. As described in chapter 1.1 the uGC has advantages for use in a process environment. These are some examples how and where they are used. 1.3.1 Natural gas & Liquified Natural Gas LNG Natural gas is bought and sold as a bulk commodity with price based on its energy content. It is very important to accurately determine the heating value/calorific value of natural gas as well as quantify individual components of the streams. The Agilent Micro GC Natural Gas Analyzer (NGA) is a 2 channel, multi-dimensional system based on the 490 Micro GC. Each channel includes a micro-machinedcapillary column, and thermal conductivity detector enabling very fast analysis cycle times (typically less than 60 seconds). (ISO 6976 (10), ASTM D3588, GPA 2286 and GPA 2172) Natural gas is a major source of energy, but many towns and cities that need the energy are located far from the gas fields. Transporting gas by pipeline can be costly and impractical. Shell (11) creates LNG by cooling the gas to a liquid at around -160ºC, which they can then ship out, safely and efficiently. LNG is a clear, colourless, non-toxic liquid that can be transported and stored more easily than natural gas because it occupies up to 600 times less space. When LNG reaches its destination, it is returned to a gas at regasification facilities. It is then piped to homes, businesses and industries. Shell (11) helped pioneer the LNG sector, providing the technology for the world's first commercial liquefaction plant at Arzew, Algeria, in 1964. Since then, Shell (11) has continued to improve the technology behind LNG. (12) Next to metering of the flow, composition analysis of LNG contributes to the correct fiscal accounting of LNG movements. The basic function of the sampler is to take a representative sample from liquid natural gas and vaporize this integrally for analysis by (micro-)GC (or other analytical equipment) or to fill a sample cylinder for transport to the lab with subsequent lab analysis. The requirements are fixed in (13). Having followed this standard there still is a too large uncertainty in the analysis results, even when the sampling is restricted in this standard to periods where the LNG transfer is at a stable (maximum) rate. The analysis’ performance itself is not questioned; it is the sampling method that causes the deviation. The main problem in sampling is the sample transport in the liquid phase from take-off to vaporisation step and a total instant vaporisation of the LNG to the gas phase to prevent discrimination of the sample. In present new design the vaporizer is integrated in the sample probe and as such has no external liquid sample transport. Moreover, a maximum of sub cooling (as specified in the a.m. ISO) is provided. Tests on the new design sampler showed immediate, accurate analysis on start of the loading. The measured relative standard deviation of the results was better than 0.17%RSD based on a composition of CH4, C2H6 and C3H8. Impurities in Natural gas are present in low concentrations (i.e. H2S, COS H2O, MeOH). Pipeline specifications dictate the maximum amounts allowed. The control and protect the levels present analysis is required. On the other hand since Natural gas is odourless small quantities of thiols (mercaptanes) derivatives are added to the gas.

Figure 19 New LNG probe design

http://www.chem.agilent.com/en-US/products-services/Instruments-Systems/Gas-Chromatography/490-Micro-GC/Pages/components.aspx


Precision, speed and low ppm quantification is required of the substance and composition of the Natural gas. In the referred applications this is achieved by uGC analyses. The analyses and the calculation of the heat values are fast to acquire as much information as possible and protect the process from impurities. The µPGC is able to deliver such speed and precision. Heat values are calculated according the above mentioned standards Reference: ref: Agilent Technology application notes 5991-0275EN, 5990-8250EN, 5990-8528EN, 5990-8750EN (14) & Analytical Solutions and Products BV: (9) 1.3.2 RGA, Cokes gas Analyses The source and composition of refinery gases varies considerably. Measuring gas composition precisely and accurately is a significant challenge in refinery operations. The Agilent Micro GC Refinery Gas Analyzer (RGA) is a 4 channel, multi-dimensional system based on the 490 Micro GC. Each channel includes a micro-machined injector, capillary column, and thermal conductivity detector optimized for specific RGA analytes, with total analysis cycle time of less than three minutes. The small system volume means the sample capacity is reduced in comparison to standard GC RGA systems and is more suitable for sample streams with low sample component concentration such as typical refinery gas streams and impurities in bulk ethylene. In Cokes gas the application is similar but more impurities may exist is the process gas. One example is given here. The analysis of Naphthalene and H2S: Reference: Agilent Technologies application note(s): SI-02233, SI-02235 Analytical Solutions and Products BV: (9) 1.3.3 Sulfur analyses (9) (14) The analyses of sulphur containing components in the different industrial gasses is a widely used measurement in the industrial environment. Sulphur is present in raw energy products when extracted from its sources for processing. Crude oils, raw coal and natural gas sources all contain sulphur in different concentrations and structure. Before crude oils are distilled in refineries or when coal is converted for the use of fuels, the sulphur is first removed from the raw feed streams. H2S and in a lesser degree organic sulphur is formed during these conversion and treating steps. When natural gas is extracted from their sources the gas is treated

Figure 21: Lemon yellow Sulphur crystals

Figure 20: Cokes Gas Analyses

http://www.chem.agilent.com/en-US/products-services/Instruments-Systems/Gas-Chromatography/490-Micro-GC/Pages/components.aspx


in gas treating plants before use as an energy source in industries or households. The H2S, COS and other organic sulphur in the gas are removed from the raw material. The importance of the removal of sulphur from the mentioned (energy) sources can be found in a number of reasons as the toxicity, corrosion and environmental pollution that will be caused by sulphur containing components. The methods for the measurement of H2S, COS and other organic sulphur are very broad. The analytical methods used is first dependent on the range and composition of the gas. Second the analytical technology available at the time of choice plays a role in the selection. Over the last decades new analytical techniques are developed and have become available for the measurement of the sulphur containing components. The emission of sulphur will be in the form of sulphur oxides after burning as SO2 or SO3 indicated as SOx. The emission of the sulphur oxides among other pollutants is restricted in Europe. The European Union states: To maintain or improve the quality of ambient air, the European Union has established limit values for concentrations of sulphur dioxide, nitrogen dioxide and nitrogen oxides, particulate matter and lead, as well as alert thresholds for concentrations of sulphur dioxide and nitrogen oxide, in ambient air. The alert threshold laid down in Directive 1999/30/EC is 500 µg/m³ measured over three consecutive hours at locations representative of air quality over at least 100 km

2 or an entire zone or agglomeration,

whichever is the smaller (15). The emitted SO2 by only the 25 European countries’ industries was approximately 5,114,779 ton in 2004 (2004 data (16)), the power and refinery industry are the largest producers of SO2.

Figure 22: Emissions of SO2 in 25 European countries in 2004 .

Therefore industrial companies have to restrict the amount of H2S and other sulphur containing components exhausted to the incinerators and vented as SO2 to the atmosphere. To control the emissions of the components analytical measurements are necessary. When regulations from governments limit the amount of pollutants, there must a way to measure and control this. This literature thesis will focus on the literature about the analyses of sulphur containing components and in particular SO2, H2S and COS in Flue gas, Fuel gas and Natural gas in a industrial environment.


New developments over the last decade allow the detection of sulphur using new detectors. The detection of SO2, H2S, COS and CH3SH in a range from 500ppbv to 5ppmv in hydrocarbon gasses could be achieved using a µGC in combination with the micro-Thermal Conductivity Detector (µTCD) and a Pora PLOT U column quantification limits of 0.5 ppm H2S in Natural Gas could be achieved with a 2-8% repeatability in the 1-3ppm H2S range. Table 3: Repeatability for 1-3ppm H2S on a µTCD (17)

H2S Conc %RSD

3ppm 2-3%

2ppm 3-4%

1ppm 8%

Figure 25: Stability and step test for 3 to 0.5ppm H2S on a µTCD

Reference Analytical Solutions and Products BV: (9) (14)

Figure 24: 5.8ppmv H2S LOQ 0.5 ppmv on a µTCD

Figure 23: Sulphur melts to a blood-red liquid. When burned, it emits a blue flame and forms SO2 from: S + O2 -> SO2


1.3.4 Syngas analyses (18) Gas To Liquids (GTL) conversion is an umbrella term for a group of technologies that can create liquid synthetic fuels from a variety of feed stocks like natural gas, biomass and coal. The basic technology was developed in Germany in the 1920s and is known as the Fischer-Tropsch process after its inventors. In essence it uses catalytic reactions to synthesize complex hydrocarbons from simpler organic chemicals. This process can create identical liquids from a variety of feed stocks, although the technical challenges are greater for biomass and coal. The Shell middle distillate synthesis process (SMDS) process (19): The Shell middle distillate synthesis process (SMDS) is a proven technology to convert hydrocarbon gas to liquid fuels. The SMDS process uses natural gas as a feedstock. Natural gas produced at remote locations where it is not directly used or necessary for direct energy consumption (in most cases the gas is simply burned off, or “flared.”) is ideal for the conversion into heavy paraffin’s by the SMDS process. It is transferred into ultra clean products. The main use is clean fuels and in particular gasoil (diesel). The produced fuels are free from sulfur and aromatics. But other products produced are FDA-approved, food-grade waxes (the waxes are used in chewing gum, cosmetics and medicines). Impurity analyses (9) The described process uses large amounts of high value cobalt (Co) or iron (Fe) catalyst. Low concentration contaminant like the before mentioned HCN poison, will deactivate the catalyst. Therefore expensive absorbers are used to prevent any of the contaminants from reaching the process vessels in which the catalyst is stored. The absorbers, which are also installed in high-volume vessels, are expensive pieces of process equipment. The µPGC analytical technique described in this paper is an economic solution for this problem. It is a small and relatively inexpensive piece of equipment that can be installed at various points in the process to monitor the contaminants. Reference: Agilent Technologies application notes: 5990-7054EN Analytical Solutions and Products (9) 1.3.5 Biogas & Biomass analyses Biogas, a renewable and sustainable energy source, is produced through biological processes like anaerobic fermentation or digestion of organic material. The main components of biogas are methane (CH4) and carbon dioxide (CO2), with some other permanent gases, hydrogen (H2) and hydrogen sulfide (H2S). The exact composition of the biogas is related to the origin of the organic material. To increase its caloric values, it can be necessary to remove some CO2 or blend it with other hydrocarbon streams. To tie into the existing natural gas network the gas must comply with the required specification and should not disturb the composition in the pipeline. Biomass has been recognized as a potential renewable and sustainable energy source. The Delft University of Technology researches the gasification of woody and agricultural biomass in a Circulating Fluidized Bed Reactor. The Agilent 490 Micro GC is used to characterize the product gas using a COX column for the permanent gases and a CP-Sil 5CB for the BTX compounds. Speed and precision is required in order to reach this goal. µPGC is able to do such required analysis.

Figure 26: ASaP standalone Biogas Analyser


Reference: Agilent Technologies application note(s): 5990-8069EN, 5990-7054EN, 5990-8529EN, SI-02215, 5990-9508EN Analysis of Biogas, 5990-9517EN. Analytical Solutions and Products (9) 1.3.6 Environmental analyses (20) For this analyses of the contaminants in a soil sample by means of a steam injection. Steam injection is used with the objective: soil decontamination. The sample contains contaminants in high concentrations of ambient air and moisture (gas phase). The sample is drawn from a ground location and handled by a processing plant.

Figure 27: Column 4m CPSil5 CB

Figure 28: Column 10m WAX 52

Low and precise analyses are required to control and report the soil cleaning process. µPGC is able to do such required analysis Reference: Agilent Technologies application note(s): 5990-8361EN, BTEX 5990-9527EN. Analytical Solutions and Products (9)


Column/Phase

Type

Target Components

Molsieve 5• Permanent gases, methane, CO, NO,etc. (H.R. for O2-Ar baseline separation). Optional Retention Time

Stability (RTS) configuration.

Hayesep A Hydrocarbons C1-C3, N2, CO2, air, volatile solvents

CP-Sil 5 & 8 CB Hydrocarbons C3-C10, aromatics, organic solvents

CP-Sil 19 CB Hydrocarbons C4-C10, high boiling solvents, BTX

CP-WAX 52 CB Polar higher boiling solvents

PLOT Al2O3/KCl Light hydrocarbons C1-C5 saturated and un-saturated.

CP-PoraPLOT U Hydrocarbons C1-C6, Freons, Anesthetics, H2S, CO2, SO2, volatile solvents

CP-PoraPLOT Q Hydrocarbons C1-C6, Freons, Anesthetics, H2S, CO2, SO2, volatile solvents

CP-COx CO, CO2, H2, Air, CH4

THT column THT and C3-C6+ in Natural Gas Matrix

TBM column TBM and C3-C6+ in Natural Gas Matrix

CP-PoraPLOT Specially tested for H2S in natural gas (10 to 50 ppm)

MES column Unique column specially tested for MES in natural gas (1 ppm)

Table 4 Micro GC Column Modules


2 From process sample to process control Often the focus is on the analyses itself while 90% of failures with process analyses occurs in the sample handling and treatment. When fast analyses are introduced the speed of sample handling should be adjusted accordingly. On-line process analyses requires a number of essential steps to make it successful. It covers the steps from the process sample take off to the transfer of the results to the process control system, which, in its turn operates the plant to the correct sample quality and yield. The steps from process sample to process control are:

1. The sample take-off from the process pipe/vessel 2. The sample pre-conditioning 3. The sample transport 4. The sample conditioning and handling including calibration 5. The sample analysis 6. The sample data processing, and finally 7. The feedback of the results to the process control system

Figure 29: the steps from process sample to process control

Generally in plant operations manual samples are taken from the process for laboratory analyses.These sample are taken by the operators of the plant. The operator fills a sample bottle with the product and brings it to the lab for further analysis. In some cases the samples are taken semi-automatic. Like a sample bombe with a piston assembly, to control the sample pressure in the bottle, is automatically filled using a process valve. These procedures introduce errors in the sample, e.g.:

The sample may be exposed to air with the consequence of oxidation and humidification of the sample.

In case of a sample in the liquid phase a gas phase may arise when the pressure drops.

In case of a sample in the gas phase a liquid phase may arise when the temperature drops.

Especially in the last two examples, impurities may drop out and the sample composition may end up different from the actual sample.

Sample flush times may differ from person to person with the risk of differences in sample composition due to insufficient flushing.

Process Computer

Process Pipe

Take Off Probe

Pre-ConditioningSample-

Conditioning

Sample-

Analysis

ResultsSample

Transport

Sample

TransportSample

Transport

Process Plant

Control

Product

Process

Plant


On-line analyses uses automatic sample handling. This excludes the human error and samples are taken under repeatable circumstances. Still errors may occur with the sample handling when strict rules are not followed. The design of the sample handling will be of influence to the sample transport time (lag time) and eventually the total analyses time, which, is the sum of the sample transport and analyses time. The automation of the process analyses will eventually result in cost reduction and yield improvement of production plants due to better control of sample handling and analyses. One of the examples is the extensive cost reduction in a catalyst protection by process analyses. Another example is the automated analyses of important gas transport lines where toxic components and energy transfer is monitored and reported. Below figure displays the process and instrumentation diagram (P&ID) of a process analyses system. It displays the essential components for process analysis in detail.

Figure 30: from process sample to process control, the P&ID 2.1 The essential steps in process analyses The essential steps in process analyses start at the sample take-off point. For this purpose a sample take-off probe is used and mounted to the process pipe to draw a representative sample from the process on 20%-80% in the cross section of the pipe. Then the pressure and temperature are conditioned in the pre-conditioning system as close as possible to the take off point. This is done at the take-off point in order to get a representative sample, to avoid the use of high pressure sample lines and to make the system faster. Next the sample is transported to the sample handling and conditioning system by heated and/or insulated sample lines. This to avoid condensation and freezing of the sample in the lines. Also heating will minimize wall adsorption effects of low sample component quantities. In some cases the sample line wall is in addition treated and coated for this purpose. The functions of a sample handling and conditioning system are (21):

to condition the sample so it is compatible with the analyser and its application. The sample conditioning includes operations as flushing, cleaning, condensing, pressure and temperature adjusting.


for stream switching, so the analyser can be used on more than one stream.

to provide for proper introduction of a calibration standard.

to transport the sample from the analyser to the desired point of rejection. Included are venting arrangements, waste disposal systems, and methods for returning the sample to the process where necessary, without adversely affecting analyser operation.

All materials used are chosen with minimum effects from corrosion, adsorption or reaction with the sample. The analytical equipment forms the heart of the system. More than the laboratory analyses, process analyses focuses on speed and reliability. The analyser must run unattended and continuous without intervention of the operator. When the results indicate an off-set condition of the particular process, the operator must be able to rely on the trueness of the results. In the impurity detection of a catalyst, a false zero indication is an even worse scenario and can result in a life threatening situation. A good example is the explosion that happened in an Air Separation Unit (ASU) at Shell’s Gas To Liquid (GTL) process in Bintulu on December 1997. Detailed investigations revealed that the explosion was not caused by any part of the plant itself, but by smoke particles from local forest fires building up in the liquefied oxygen in the ASU. Fast (process) analyses of the hydrocarbons in the oxygen could have detected the threatening situation and prevented the accident. Therefore tools must be available on the analytical equipment to confirm the correctness of the measurement. Statistical control carts are used to monitor the performance of the analytical equipment over time. Instead of calibrating the instrument on time base it is subjected to a control sample tested against warning and control limits for decision of corrective action. From the large number of analytical techniques available for process analyses some methods used for online compositional process analyses can be listed as follows:

1. Chromatography a. Micro Gas Chromatography b. Gas Chromatography

2. (Laser-) Spectroscopy a. Photo-(acoustic laser) spectroscopy b. Cavity ring down spectroscopy

3. Mass-spectrometry a. Ion mobility spectroscopy b. Field Asymmetric Ion Mobility Spectrometry

Finally results are transferred to the process control system using a standard industrial communications protocol like Modbus

TM or Fieldbus

TM. Reason for such standard is the diversity in instrumentation used in

a plant. In general the protocols must be able to accurately transfer the data and inform the operator about the condition of the instrument. Generally analytical instruments are equipped with redundant communications outputs to ensure data pass to the control system in case one of the outputs fail or one of the communication routes are blocked. The result transfer may also include the tools for a process operator to start for example a so called benchmark analysis to confirm the correctness of the measurement of the analytical equipment. 3 Sample handling and integration back ground information Sample handling is often forgotten to be one of the most important aspects for process analysis. While in laboratory environment the sample handling is a well addressed issue (2) in process analysis the focus is commonly on the analysis itself. A number of developments in the area of process analysis sampling will be addressed here.


First a conventional process sample handling system consists of a sample take-off and preconditioning system, sample transport and sample conditioning and calibration system. These are basic blocks needed to built a sample handling system. The particular parameters that need to be controlled are pressure, flow and temperature, clean-up of the sample by filtration, liquid separation and calibration. For example when a system is build to analyse environmental samples the pressure is normally atmospheric and a pump is needed to pull the sample through the system, then liquids are taken out of the system using a cooler in combination with a peristaltic pump, after which temperature is slightly elevated above the dew point to prevent any gasses to condense during transport and further treatment. One important aspect here is not to drop-out any of the components of interest during the liquids drop-out step. Another example where the sample is taken from a process at a high pressure. Normally the pressures at the process pipe, particular in natural gas transport, are relative high (50-100 barg). To be able to analyse the sample with an analyser, which is generally done at a few bar gauge, the sample first needs to be reduced in pressure. Doing that a pressure drop will result in a temperature drop due to the Joule Thompson effect (also called a throttling process). This results in unwanted effects like freezing at the sample take-off point. The sample handling device to neutralize this effect is a vaporizing regulator. This device is often installed at the sample take-off point as close as possible to the sample probe. A new development is a probe which uses the process fluid energy in conjunction with an internal heat transfer device to heat the pressure regulator installed at the bottom in the probe to neutralize the temperature drop effect (see Figure 31)

Figure 31 Genie Retractable Probe Regulator Model GPR with integrated membrane (courtesy of Genie inc.).


3.1.1 Further developments in sample handling (NeSSI™) (22)

A new development in sample handling is the NeSSI platform which reduces conventional sample handling systems to a standardized miniaturized platform. The NeSSI initiative was begun to simplify the tasks, and reduce the overall costs, associated with engineering, installing and maintaining chemical process analytical systems. NeSSI is an acronym for New Sampling/Sensor Initiative. The specific objectives of NeSSI are:

to increase process analytical system reliability,

through the use of increased automation,

shrink the physical size, sample and energy use by means of miniaturization,

decrease sample flush times by analyser and sample handling integration,

promote the creation and use of industry standards for process analytical systems,

and help create the infrastructure needed to support the use of the emerging class of robust and

selective micro-Analytical sensors.

Figure 32: standardized building block for the NeSSI platform (courtesy of Circor Tech)

The sample handling building blocks are standardized resulting in simplified engineering and construction of the sample handling system. The components are interchangeable which reduces the cost and maintainability.

Figure 33: a sample handling system on the NeSSI platform (courtesy Circor Tech)

The sample volume Vsample in

is reduced to a minimum on this platform.

http://www.circortech.com/Circor/servlet/ProductDetail?id=115


A number of other analytical devices/sensors are available on this platform; e.g. a photometer, a moisture sensor, a viscosity meter and an oxygen sensor. An interesting development from EIF is the Astute 3D Probe. Here the integration reaches an ultimate level, the sample take-off probe, sample preconditioning, and sample analysis are all integrated in one device.

Figure 34: all steps from sample take-off to analysis integrated in one 3D probe (courtesy of EIF)

3.1.2 Integration of equipment in process plants a slim analyser package (aSAP) (9)

Another new development of further integration of equipment with its sample handling in a process plant and the increase of sampling speed has been developed by ASaP BV the Netherlands. It consists of a flexible cabinet called a Slim Analyser Package (aSAP) with integrated sample handling and . For the analyser(s) and maintenance personnel a weather protective enclosure is provided. The

construction of the enclosure is such that by opening both enclosure doors are at an angle of 90, a

weather protective area is created for maintenance personnel. Both doors will be fixed at 90 by special plastic breaking rods. In case of an emergency maintenance personnel can walk/fall through the doors

which will open to 180. This concept called will enclose the requested analyser(s) and its sample handling system and utilities.

Direct on top of the pipeline installation is possible with this setup. It will also reduce overall installation and engineering costs. Below example shows the integration

Figure 36: a Slim Analyser Package (aSAP), the back wall is transparent for illustration

Figure 35: on pipeline installation including side platform


steps of a µGC into a Process (ATEX) certified µPGC and an aSAP analyser package. 4 Discussions and Conclusions Micro Gas Chromatography (µGC) is an interesting development for process analyses. For reasons of:

The high speed of the analysis.

The small size, high robustness and reliability of the instrument.

The low consumption of utilities (power and carrier) and sample.

The advantage towards EMC and ATEX certification and integration.

The modular design for the ease of adaption of laboratory applications. The µGCs selected was Agilent 490-GC µGC. The selection was based on how well the µGC could be used in process analyses. The reason for the selection can be summarized as follows:

The application frame is extensive and applications can be selected and extended by adding/combining modules with different columns. A feature to flush out components is available.

The uGC has heated injectors, sample lines and inlets with a temperature up to 110°C to handle high boiling point samples in the gas phase. The sample inject volume is variable and can be reconfigured in seconds.

The uGC has µTCDs which allows for a wide dynamic range (ppmv – vol%) and universal detection of components.

ATEX/CSA certification (for explosion safe operation) and environmental protection is available.

Long term hardware field tests are performed and confirm suitability for process installation.

Unattended operation and tools to confirm the correctness of the µGC are available.

The manufacturer Agilent Technologies made a choice to make the instrument suitable for process analyses.

4.1 Further discussion for process analysis Due to the fast process analyses the µGCs require special features like special software and hardware tools, fast sample handling and features to prevent the analytical column from unwanted impurities and high boiling point components.

Analytical Channel

µGC Casing

Process

micro GC

Analytical Shelter Figure 37 a µGC integrated into a Process (ATEX)

certified µPGC and an aSAP analyser package


The Agilent 490-GC µGC uses a back-flush system. The integrated software for standalone operation with an industrial standard communications output like Modbus and a ATEX Zone1 and 2 certification (9) results in a µGC fit for process analysis. The optional Differential Mobility Detector (DMD) is an interesting development for selective impurity measurement. The µGC has a repeatability <0.5%RSD based on normalized data with day-night influences included. Finally it must be emphasized that an advantage for the µGC is the speed of analysis (0,5-1,5 minutes) the low utilities and power consumption and low sample waste. It size allows for integration and installation direct on the process pipe. Modular design allows maintenance on a plug and play basis. Future developments on the µGCs should include features for:

liquid injection for liquid (petro)chemical & bio-chemical applications

multi method and multi stream operation

remote communications and

expand the detector range for low concentration and selective detection of impurities

column switching


5 References 1. Blomberg, Jan. Multidimentional GC-based separations for the oil and petrochemical industry. Amsterdam : s.n., 2002. ISBN 90-9016065-5. 2. Schoenmakers, Peter, et al. Chromedia. Chromedia. [Online] 02 01, 2008. [Cited: 02 01, 2009.] http://www.chromedia.org. 3. Theoretical Aspects and Practical Potentials of Rapid Gas Analysis in Capillary Gas Chromatography. Thijssen, Robert, Hoed, Nico van den and Kreveld, M. Emile van. 1007-1015, Amsterdam : Anal. Chem., 1987, Vol. 59. 4. Cramers, Carel A., et al. High-speed gas chromatography: an overview of various concepts. Journal of chromatography A. 856, 1999, Vol. 856(1999). 5. Some reflections on speed and efficiency of modern chromatographic methods. Poppe, H. A, 778 3-21, Amsterdam : Elsevier, 1997. 6. Es, Andrew van. High speed narrow bore capillary gas chromatograpy. Heidelberg : Huthig Buch verlag GmbH, 1992. ISBN 377852027X. 7. High Speed Portable Gas Chromatography. Bruns, Mark. W. 1994. 8. Technologies, Agilent. Scanview. Agilent technologies Scanview. [Online] 07 29, 2012. [Cited: 07 29, 2012.] http://www.chem.agilent.com/en-us/search/library/Pages/CompoundSearch.aspx?a=scope:%22Library%22+lngcontenttype:%22application%22. 9. Analytical Solutions and Products B.V. ASaP Producten and Application Notes. ASAP Producten. [Online] 10 01, 2007. [Cited: 12 03, 2011.] http://www.asap.nl. 10. STANDARDIZATION, NEN INTERNATIONAL ORGANIZATION FOR. Ref. No. ISO 6976:1995(E) & Cor.2:1997(E). Natural gas — Calculation of calorific values, density, relative density and Wobbe index from composition. Switzerland : NEN, 1995, 1997. Vol. 1997. 11. Solutions, Shell Global. What is LNG? http://www.shell.com/. [Online] Shell Global Solutions, 07 24, 2012. [Cited: 07 24, 2012.] http://www.shell.com/home/content/future_energy/meeting_demand/natural_gas/lng/what_is_lng/. 12. Doeschgate, ir Henk Ten and Lenior, drs ing Tim. LNG Sampler with sample conditioning and micro Process Gaschromatograph. Amsterdam : ASaP BV & Doesco, 2012. 13. NEN. ISO 8943: 2007. LNG Sampling. Switserland : NEN, 2007. Vol. 2007. 14. Lenior, Tim. Literature Thesis Tim Lenior Analytical Sciences Aug 2009 ver1. Amsterdam : VU University, 2009. 15. Agency, European Environment. Annual European Community LRTAP Convention emission inventory report 1990–2006. Copenhagen : European Environment Agency, 2008. ISBN 978-92-9167-366-7. 16. Register, EPER: the European Pollutant Emission. EPER Review Report 2004. Copenhagen K, Denmark : European Commission, 2007. 17. Adrichem, Arno van. H2S Testdata. Rotterdam : Exxon Mobil, 2009. 18. Gas-to-Liquids. EP Technology. no.1, 2008, Vol. 2008, 1. 19. Meyers, Robert A. HANDBOOK OF PETROLEUM REFINING PROCESSES Third edition. s.l. : McGraw-Hill, 2004. 20. Tim Lenior and Hans-Peter Smid, Asap, the Netherlands. Remko van Loon , Agilent Technologies, Inc, the Netherlands. Analysis of Acetone, n-Hexane, MIBK,MNBK and MIBC Using the Agilent 490 micro GC. Amsterdam : Dura Vermeer, ASaP BV, Agilent Technologies Inc, 2011. 21. Wealleans, Fred. THE SIX FUNCTIONS OF ANY SAMPLING SYSTEM. Milton Keynes : PASS, 2002. 22. New Sampling/Sensor Initiative (NeSSI™). New Sampling/Sensor Initiative (NeSSI™). [Online] 05 01, 2009. [Cited: 05 01, 2009.] http://www.cpac.washington.edu/NeSSI/NeSSI.htm.

Fast Analysis of Natural Gas Usingthe Agilent 490 Micro GC NaturalGas Analyzer

Author

Remko van Loon,

Agilent Technologies,

Middelburg, the Netherlands

Application Note

Micro Gas Chromatography, Hydrocarbon Processing, Natural Gas Analysis

Abstract

During production and distribution of natural gas it is of high importance to

determine its composition and calorific value because natural gas is bought and

sold on its energy content. This application note shows the use of the Agilent 490

Micro GC Natural Gas Analyzer for the analysis of natural gas and the calculation of

its heating value. With the 490 Micro GC, Agilent provides ideal solutions for

laboratory, on-line and field use.

2

Introduction

Natural gas mainly consists of methane and variable levels ofother hydrocarbons and permanent gases such as oxygen,nitrogen, and carbon dioxide. Different sources of natural gasusually have similar composition but vary in concentration.

Natural gas is traded on its energy content and therefore theanalysis of the chemical composition and calorific value is ofhigh importance for all stakeholders. That is where the490 Micro GC based Natural Gas Analyzer can play a significant role.

The 490 Micro GC Natural Gas Analyzers are shipped as atotal solution; the analyzers are factory tuned, for optimalseparation, and come with final test data, a complete method,a user manual, and a check-out sample. Easy-to-use softwareis available for the calculation of all required physicalproperties, such as heating value and Wobbe index, conformofficial methods from the American Society of Testing andMaterials (ASTM), Gas Processors Association (GPA) andInternational Standards Organization (ISO).

Natural Gas Analyzer setup Based on the 490 Micro GC, four Natural Gas Analyzers areavailable, depending on the composition of the natural gasand the compounds of interest. The configurations andanalysis characteristics for all analyzers are shown in Table 1.Additional information for the configurations can be found inNatural Gas Analyzer Data Sheet [1].

The Natural Gas Analyzers are equipped with heated injectorsand sample lines, both set to 110 °C in the analyzer method,to eliminate any cold spots and prevent possible condensationof moisture, and to ensure the integrity of the sample is maintained throughout the sample flow path.

Table 1 shows multiple column channels are equipped with aback flush to vent option. To protect the CP-Molsieve 5Astationary phase and maintain the separation efficiency of themolecular sieve column, it is necessary to back flush carbondioxide, moisture, and higher hydrocarbons. Moisture andcarbon dioxide tend to adsorb quickly to the molecular sievestationary phase change its chromatographic properties. Thiscan result in retention shifts and loss of separation. Higherhydrocarbons will eventually elute, but will cause higherdetector noise levels and would lead to reduced sensitivity;the back flush to vent functionality on the Molsieve 5Acolumn channel prevents this from happening. On thePoraPLOT U and HayeSep A channels, the higherhydrocarbons, C4 and higher, are back flushed to vent. Thisprevents these late eluting components from interfering in thenext analysis.

Table 1. Agilent 490 Micro GC Natural Gas Analyzers Overview.

Analyzer characteristics

Natural Gas Analyzer A

Natural Gas Analyzer A Extended

Natural Gas Analyzer B

Natural Gas Analyzer B Extended

Micro GC cabinet Dual with 2 channels Quad with 3 channels Dual with 2 channels Quad with 3 channels

Column channels installed HayeSep A 40 cm, without backflush

HayeSep A 40 cm, with backflush

PoraPLOT U 10 m, with backflush

CP-MolSieve 5A 10 m, with backflush and retention time

stability option

CP-Sil 5 CB 6 m, without backflush

CP-Sil 5 CB 4 m, with backflush


PoraPLOT U 10 m, with backflush



Analysis Hydrocarbons C1-C9Carbon dioxide, Air

Hydrocarbons C1-C12Carbon dioxide, Air

Hydrocarbons C1-C9Carbon dioxide, Air, Hydrogen sulfide

Hydrocarbons C1-C9Carbon dioxide, Air, Hydrogen sulfide Permanent gases (N2, O2, He and H2)

3

The CP-Molsieve 5A is equipped with the retention timestability (RTS) option. This RTS option consists of additionalin-line filters between the electronic gas control and thecolumn module to ensure moisture and carbon dioxide freecarrier gas. The use of the RTS option enables a more efficientback flush of carbon dioxide. This enhances column lifetimeand, most importantly, leads to more stable retention times.

The natural gas sample can be introduced to the 490 MicroGC either pressurized (maximum limit 1 bar), through a Tedlarsampling bag using the internal sampling pump, or by usingcontinuous flow sampling mode. When you need to analyzemultiple streams on a single analyzer or you want to connectmultiple calibration samples for automated calibration, theuse of a stream selector valve is recommended.

To expand the range of samples to Liquid Petroleum Gas(LPG) and Liquefied Natural Gas (LNG), the Micro-Gasifierprovides controlled evaporation before the sample isintroduced into the gas chromatographic injector for analysis.In addition, high-pressure gas samples can be reducedwithout creating cold spots, which prevents discrimination in the sample.

0 30 60 90 120

Seconds

200 × Zoom

1

2

3

4

4

5

3

20 × Zoom

5

ConditionsColumn temperature 60 °CCarrier gas helium, 260 kPaInjection time 40 ms

Figure 1. Chromatogram for nitrogen, carbon dioxide, and C1 – C3 hydrocarbons on a HayeSep A column.

Peak identification

1. composite air peak2. methane3. carbon dioxide4. ethane5. propane

Fast Natural gas analysis using the Natural GasAnalyzer AThe first channel in the Natural Gas Analyzer A is equippedwith a HaySep A column for separating methane from thecomposite air peak (nitrogen and oxygen). Carbon dioxide,ethane, and propane are analyzed on this column channel aswell. Figure 1 shows an example chromatogram for thesecompounds.

For the analysis of the hydrocarbons from propane ton-nonane, a second column channel, equipped with a 6-meterCP-Sil 5 CB column, is used. Figure 2a shows a chromatogramon the 6-meter CP-Sil 5 CB for the separation until n-octane;n-hexane elutes in less than 60 seconds and n-octane in justover 3 minutes. Propane is analyzed on both HayeSep A andCP-Sil 5 CB column enabling the use of propane as a bridgecomponent. The extended part of the chromatogram obtainedwith a 6-meter CP-Sil 5 CB column, displayed in Figure 2b,shows the analysis of hydrocarbons until n-nonane.

4

0 30 60 90 120 150 180 210Seconds

20 × Zoom

7

1

2 34

5 6

8 9


160 220 280 340 400

Seconds

109

100 × Zoom

Figure 2a. Chromatogram for C3 – C8 hydrocarbon using a 6-meter CP-Sil 5 CB column.

Figure 2b. Chromatogram for C8 – C9 hydrocarbons using a 6-meter CP-Sil 5 CB column.

Peak identification

1. propane2. i-butane3. n-butane4. neo-pentane5. i-pentane6. n-pentane7. n-hexane8. n-heptane9. n-octane

Peak identification

9. n-octane10. n-nonane

Analysis up to n-dodecane with the Natural GasAnalyzer A ExtendedThe extended version of the Natural Gas Analyzer A is usedfor the analysis of natural gas until n-dodecane. This extendedanalyzer is equipped with three column channels. First, aHayeSep A column channel is used for separation ofcomposite air peak from methane, carbon dioxide ethane, andpropane. This channel is equipped with back flushfunctionality ensuring that butanes and later elutinghydrocarbons are back flushed to vent. Figure 3 shows anexample for the HayeSep A channel, propane is eluting in lessthan 2 minutes.

5

Figure 3. Chromatogram for HayeSep A column with backflush.

0 30 60 90 120

Seconds

1

2

3

4

4

5

3 5

ConditionsColumn temperature 90 °CCarrier gas helium, 340 kPaInjection time 20 msBackflush time 120 s

20 × Zoom 100 × Zoom

Peak identification

1. composite air peak2. methane3. carbon dioxide4. ethane5. propane

Figure 4. Chromatogram for C3 to C5 hydrocarbons on a 4-meter CP-Sil 5 CB.

0 10 20 30Seconds

1

2 3

4 5 6

20 × Zoom


Peak identification

1. propane2. i-butane3. n-butane4. neo-pentane5. i-pentane6. n-pentane

The second channel, equipped with a 4-meter CP-Sil 5 CBcolumn with back flush functionality, is used to analyze C3 toC5 hydrocarbons; the chromatogram is shown in Figure 4.N-hexane and higher hydrocarbons are back flushed to vent.

6

A third column channel, equipped with a 8-meter CP-Sil 5 CBcolumn, is used to analyze the higher hydrocarbons fromn-hexane to dodecane; n-Dodecane elutes in approximately240 seconds. A natural gas sample sample until n-decane,demonstrated in Figure 5a, is analyzed in less than 2 minutes.Figure 5b displays a hydrocarbon gas mixture from n-hexaneuntil n-docecane, typical analysis time is 240 seconds.

Analysis of natural gas including hydrogen sulfideusing the Natural Gas Analyzer BWhen your natural gas analysis needs to include hydrogensulfide, the 490 Micro GC Natural Gas Analyzer B is theanalyzer of choice. This analyzer uses a PoraPLOT U columnchannel for the separation of methane from the composite airpeak (nitrogen and oxygen). This column is also used for theanalysis of carbon dioxide, ethane, and propane. Thechromatogram in Figure 6 shows an example of natural gason the PoraPLOT U column; total analysis is done inapproximately 60 seconds. For the analysis of hydrogensulfide, the stainless steel tubing in the PoraPLOT U channel

0 60 120 180 240Seconds

13

4

5

2

6 7

Figure 5b. Analysis C7 – C12 hydrocarbon mix on an 8-meter CP-Sil 5 CB.

Peak identification

1. n-hexane2. n-heptane3. n-octane4. n-nonane5. n-decane6. n-undecane7. n-dodecane

0 30 60 90 120

Seconds

1

3

54

2

4 5


5 × Zoom

Figure 5a. Analysis of natural gas on an 8-meter CP-Sil 5 CB.

Peak identification

1. n-hexane2. n-heptane3. n-octane4. n-nonane5. n-decane

and the sample inlet of the Micro GC have an UltiMetaldeactivation layer, which results in an inert sample flow pathand excellent peak shape ensuring correct analysis ofhydrogen sulfide even at ppm level.

Hydrocarbon analysis from propane until n-nonane for theNatural Gas Analyzer B is done with a second channelequipped with a 6-meter CP-Sil 5 CB. This column is identicalto the one used for the Natural Gas Analyzer A.The chromatograms for this channel are displayed inFigure 2a and 2b.

7

Permanent gas analysis using Natural GasAnalyzer B ExtendedThe Extended version of the 490 Micro GC Natural GasAnalyzer B is equipped with an additional CP-MolSieve 5Acolumn channel for the analysis of permanent gases in yournatural gas sample. Helium carrier gas on this channelenables the separation and quantification of oxygen andnitrogen, an example is shown in Figure 7 (top part).

15 30 45 60 75

Seconds

1

2

3

4

5

45

3

6

6


10 × Zoom100 × Zoom

Figure 6. Chromatogram for natural gas on the PoraPLOT U column channel.

When you need to analyze helium, neon, or hydrogen as well,the use of argon instead of helium as carrier gas is required.The bottom part of Figure 7 shows a chromatogram for themolecular sieve column running with argon as carrier gas. Tohave the flexibility to change the carrier gas for only themolecular sieve column to argon, this channel is connected toa separate carrier gas inlet at the rear of the micro GC.

Peak identification

1. composite air peak2. methane3. carbon dioxide4. ethane5. hydrogen sulfide6. propane

0 15 30 45 60 75Seconds

1

3

4

5

6

5

6

42

Sample 1Helium carrier gas

Sample 2Argon carrier gas

20 × Zoom

5 × Zoom


ConditionsColumn temperature 80 °CCarrier gas argon, 200 kPaInjection time 40 msBackflush time 11 s

Figure 7. Chromatograms for the analysis of permanent gases on the CP-MolSieve 5A column channel.

Peak identification

1. helium2. neon3. hydrogen4. oxygen5. nitrogen6. methane

Conclusion

Micro GC Natural Gas Analyzer is a genuinely better solutionfor analyzing your natural gas stream. Whether in the lab,on-line/at-line, or in the field, the “Measure Anywhere”Micro GC provides natural gas analysis in a matter of seconds.

The Natural Gas Analyzer A analyzer combined with aHayeSep A and 6-meter CP-Sil 5 CB column channel is usedfor the analysis of natural gas. This analyzer will separatemethane from air and can analyze up to n-nonane. Carbondioxide is also analyzed. Total analysis time depends on thehydrocarbons in the sample; up to n-heptane is done inapproximately 90 seconds, n-nonane elutes just under400 seconds.

When you want to analyze until n-dodecane in natural gas,the Natural Gas Analyzer A Extended is required. The 6-meterCP-Sil 5 CB column channel is replaced by two different CP-Sil 5 CB channels. A short CP-Sil 5 CB (4-meter) will analyzefrom propane to the pentanes; hexane and higher will be backflushed to vent. The second CP-Sil 5 CB channel, with an8-meter column, is used for analysis of hexane up ton-dodecane.

8

Reporting tools for the physical properties of natural gasThe results for all individual components are sent from thechromatography data software of choice (EZChrom Elite,OpenLAB EZChrom, or OpenLAB Chemstation) to optionalEZReporter software to calculate a wide range of physicalproperties like, calorific value, relative density,compressibility, and Wobbe index, see Figure 8 (left). Thesekey parameters are important to determine the commercialvalue of the natural gas. EZReporter supports reports inaccordance with official methods ASTM D3588, ISO 6976, andGPA 2172. The reports can be printed locally or exported to afile for further use in a laboratory information managementsystem (LIMS).

The software includes functionality to select raw analysisamounts and calculated key parameters for monitoring andhistorical trend analysis. Upper and lower warning limits canbe given to these monitor parameters to better visualize theresults from your natural gas stream. Some examples aregiven in Figure 8 (middle and right).

Figure 8. EZReporter, sample results with calculated physical properties (left), parameter monitoring (middle), and trend analysis (right).

9

The Natural Gas Analyzer B, equipped with a PoraPLOT Uand a 6-meter CP-Sil 5 CB CB column channel, provides fastanalysis of natural gas, from the separation of air andmethane, carbon dioxide, and hydrocarbons up to n-nonane.This analyzer setup is designed for the analysis of hydrogensulfide. The stainless steel sample inlet of the systsm isdeactivated using an UltiMetal treatment resulting inexcellent peak shape for hydrogen sulfide.

If more detailed analysis of the permanent gases in thenatural gas sample is required, the extended version of theNatural Gas Analyzer B is the system of choice. This analyzeris equipped with an additional CP-MolSieve 5A columnenabling the separation of oxygen and nitrogen, using heliumas carrier gas. When this analyzer uses argon as carrier gas,helium and hydrogen can be detected as well.

The 490 Micro GC Natural Gas Analyzers are factory tuned,including the appropriate settings for the back flush times.The Agilent Natural Gas Analyzers are shipped with final testdata, optimized analytical method, Natural Gas Analyzer UserManual, and a check out sample kit to have all informationavailable upon installation.

The analyzer hardware together with your chromatographydata system (CDS) of choice provides an easy-to-use andpowerful system. The EZReporter software is linked toAgilent CDS, resulting in automatic calorific value/BTUcalculations and reports according to American Society ofTesting and Materials (ASTM D3588), Gas ProcessorsAssociation (GPA 2172), and International StandardsOrganization (ISO 6976).

For more information about the 490 micro GC Natural GasAnalyzer or other Micro GC solutions, visit our website atwww.agilent.com/chem/microgc.

References

1. 5991-0301EN; Agilent 490 Micro GC Natural GasAnalyzers; Data Sheet; April 2012.

For More Information

These data represent typical results. For more information onour products and services, visit our Web site atwww.agilent.com/chem.

www.agilent.com/chem/microgc

Agilent shall not be liable for errors contained herein or for incidental or consequentialdamages in connection with the furnishing, performance, or use of this material.

Information, descriptions, and specifications in this publication are subject to changewithout notice.

© Agilent Technologies, Inc., 2012Printed in the USAApril 16 20125991-0275EN

Analysis of Tetrahydrothiophene (THT) in Natural Gas using the Agilent 490 Micro GC

Author

Remko van Loon

Agilent Technologies

Middelburg

The Netherlands

Application Note

Micro Gas Chromatography, Natural Gas Analysis, Sulfur CompoundAnalysis

Introduction

This application note shows the analysis of Tetrahydrothiophene (THT) in a NaturalGas matrix using the Agilent 490 Micro GC. THT consists of a five-membered ringcontaining a sulfur atom and four carbon atoms. THT is used as an odorant inNatural Gas, because of its smell.

The chromatogram clearly shows the separation of THT from the other compoundsin the Natural Gas sample. The dimensions for the column channel used, a CP-Sil 19 CB for THT, are optimized for this application. Moreover, this column channel is factory tested to ensure the separation between THT and Nonane.

The advantage of the Agilent 490 Micro GC, in combination with the CP-Sil 19 CBcolumn channel, is the ease-of-use and the speed of analysis. Tetrahydrothiopheneeluetes around 40 sec and the total analysis time is less than 90 sec.

The Agilent 490 Micro GC is a rugged, compact, and portable lab-quality gas analy-sis platform. When the composition of gas mixtures is critical, count on this fifthgeneration micro gas chromatography.

www.agilent.com/chem



© Agilent Technologies, Inc., 2011Printed in the USAJune 29, 20115990-8528EN

InstrumentationInstrument Agilent 490 Micro GC (G3581A)

Column channel CP-Sil 19 CB for THT

Column temperature 90 °C

Carrier gas Helium, 200 kPa

Injection time 255 msec

Injector temperature 110 °C

Sampling time 30 sec



S

Analysis of tert-Butyl Mercaptan inNatural Gas on a CP-Sil 13 CB Using theAgilent 490 Micro GC

Author

Remko van Loon

Agilent Technologies Inc.

Middelburg, The Netherlands

Application Note

Micro Gas Chromatography, Hydrocarbon processing, Natural GasAnalysis

Introduction

This application note shows the analysis of tertiary-butyl mercaptan (TBM) in anatural gas matrix using the Agilent 490 Micro GC. The dimensions and instrumentconditions for the column channel used in this application note, a CP-Sil 13 CB,clearly shows the separation of TBM from the other compounds in the natural gassample.

The advantage of the Agilent 490 Micro GC, in combination with the CP-Sil 13 CBcolumn channel, is the ease of use and the speed of analysis. Tertiary-butylmercaptan elutes just before 60 seconds and the total analysis time is only100 seconds.

The Agilent 490 Micro GC is a rugged, compact and portable lab-quality gas analysisplatform. When the composition of gas mixtures is critical, count on this fifthgeneration micro gas chromatography.

www.agilent.com


Information, descriptions, and specifications in this publication are subject to change without notice.

© Agilent Technologies, Inc., 2011Printed in the USAMay 27, 20115990-8250EN


These data represent typical results. For more information onour products and services, visit our Web site atwww.agilent.com.


Column channel CP-Sil 13 CB for TBM

Column temperature 40°C



Sample informationNatural gas Matrix

Tert-butyl mercaptan (TBM) 4 ppm

tert-Butyl Mercaptan

15 x Zoom

20 40 60

seconds

80 100

tert-Butyl Mercaptan

SH

CH3C CH

3

CH3

Analysis of Methyl Ethyl Sulfide (MES) in Natural Gas using the Agilent 490 Micro GC

Authors

Mohamed Bajja and Remko van Loon,

Agilent Technologies, Inc.

Middelburg,

The Netherlands

Application Note

Micro Gas Chromatography, Natural Gas Analysis, Sulpher CompoundAnalysis

Introduction

This application note shows the analysis of Methyl Ethyl Sulfide (MES) in natural gasusing the Agilent 490 Micro GC. Methyl Ethyl Sulfide is an organosulfur compoundwith a characteristic odor, and therefore used in some countries as an odorant fornatural gas.

This Micro GC column channel is equipped with a special dedicated column, MES innatural gas, for the separation of MES from the other compounds in natural gas.Moreover, this column channel is factory tested to ensure the separation between n-Decane and MES.

If you want to the ability to measure anywhere and get the results you need in sec-onds, the Agilent 490 Micro GC is the ideal solution. With its rugged, compact, labo-ratory quality gas analysis platform, the 490 Micro GC generates more data in lesstime for faster, and better, business decisions.




© Agilent Technologies, Inc., 2011Printed in the USAAugust 26, 20115990-8750EN

Instrumentation

Instrument Agilent 490 Micro GC (G3581A)

Column channel MES in natural gas





Sampling time 30 sec



60 90Seconds

n-Decane

Matrix

Methyl Ethyl Sulfide (MES)

120

H3CS CH3

Sample information

n-Decane 11 ppm

Methyl Ethyl Sulfide (MES) 14 ppm

Analysis of Biogas Using the Agilent 490Micro GC Biogas Analyzer

Author

Remko van Loon



Application Note

Micro Gas Chromatography, Hydrocarbon Processing, RenewableEnergy, Biogas Analysis

Abstract

Biogas is considered a renewable and sustainable energy source and therefore is of

great interest worldwide. This application note shows the analysis of biogas, and

related samples, using the Agilent 490 Micro GC Biogas Analyzer. Depending on the

biogas composition two configurations are available; the Agilent 490 Micro GC Biogas

Analyzer for pure biogas analysis and the Agilent 490 Micro GC Biogas Analyzer

Extended when biogas is mixed with other hydrocarbon streams, such as natural gas

or liquefied petroleum gas (LPG).

Introduction

Biogas is a gas mixture produced through biological processes; from anaerobic fermentation or digestion of organic material such as biomass, manure or sewage,municipal waste and energy crops. The composition of biogas is related to the originof the organic material; the main components of biogas are methane and carbondioxide, with some other permanent gases, hydrogen and hydrogen sulfide.

Biogas has a role in modern waste management and can fuel any type of heatengine to generate either mechanical or electrical power. To increase its caloricvalues it is sometimes necessary to remove some of the carbon dioxide or blend itwith other hydrocarbon streams. Biogas can be compressed, much like liquefiednatural gas, and used to power motor vehicles. For this purpose, it is essential toremove hydrogen sulfide if present. Biogas is a renewable fuel, and so it qualifies forrenewable energy subsidies in some parts of the world.

The increased interest in biogas has resulted in a growing demand for fast and efficient analysis technology to determine its composition. The Agilent Micro GCBiogas Analyzers can play a significant role in achieving this goal.

2

The Agilent 490 Micro GC Biogas Analyzers are shipped as atotal solution; the analyzers are factory tuned, for optimal separation, and come with final test data, analytical methodparameters, a user manual and a check-out sample.

Biogas Analyzer setup and conditionsBased on the Agilent 490 Micro GC, two Biogas Analyzers areavailable; the configuration required for biogas analysisdepends on the sample composition.

For pure biogas analysis, including permanent gases andhydrogen sulfide, the Agilent 490 Micro GC Biogas Analyzer(p/n G3582A#110) is recommended, even ethane andpropane can be analyzed with this setup. This BiogasAnalyzer consists of a dual channel cabinet including a10-meter CP-Molsieve 5A with argon as a carrier gas, provid-ing excellent sensitivity and linearity for hydrogen, and a10-meter CP-PoraPLOT U column channel with helium as carrier gas.

When biogas is mixed with other hydrocarbon streams suchas natural gas or liquefied petroleum gas (LPG), the samplecontains higher boiling hydrocarbons. To analyze these hydro-carbons the Agilent 490 Micro GC Biogas Analyzer Extendedis the analyzer of choice. This Biogas Analyzer Extended(p/n G3582A#111) is a quad channel cabinet Micro GCincluding three column channels; a 10-meter CP-Molsievecolumn on argon as carrier gas, a 10-meter CP-PoraPLOT Ucolumn and an additional 6-meter CP-Sil 5 CB column onhelium as carrier gas for the analysis of higher boiling hydro-carbons. Figure 1 shows the quad and dual cabinet housingfor the Agilent 490 Micro GC Biogas Analyzers.

Both Biogas Analyzers are equipped with heated sample lineand injectors to eliminate any cold spot and prevent possiblecondensation of moisture, to ensure the integrity of thesample is maintained throughout the sample flow path. BothCP-Molsieve 5A and CP-PoraPLOT U columns have a back-flush to vent option, moreover the CP-Molsieve 5A isequipped with the retention time stability (RTS) option. ThisRTS option consists of additional in-line filters between theelectronic gas control and the column module to ensure mois-ture and carbon dioxide free carrier gas. Moreover the use ofthe RTS option enables a more efficient backflush of carbondioxide. This enhances column lifetime and, most importantly,leads to more stable retention times.

Table 1 gives an overview of typical conditions used for theBiogas Analyzers.

Figure 1. Agilent 490 Micro GC Biogas Analyzers.

Table 1. 490 Micro GC Biogas Analyzer Instrument Conditions

CP-Molsieve 5A, 10 m CP-PoraPLOT U, 10 m CP-Sil 5 CB, 6 m

Column temperature 80 °C 80 °C 60 °C

Carrier gas argon, 200 kPa helium, 150 kPa helium, 150 kPa

Injector temperature 110 °C 110 °C 110 °C

Injection time 40 ms 40 ms 40 ms

Backflush time 1 11 14 no backflush

Detector sensitivity auto auto auto

Invert signal yes no no

Sample line temperature 110 °C

Sampling time 30 seconds

Note 1 Backflush time is column channel dependent and should be fine tuned for each new column.

3

The sample can be introduced to the Agilent 490 Micro GCBiogas Analyzer either pressurized (maximum limit 1 bar),through a Tedlar sampling bag using the internal samplingpump, or by using a continuous flow sampling mode. Whenthe sample pressure exceeds the 1 bar limit, for example witha liquefied natural gas or liquefied petroleum gas, the pressure should be reduced. The use of the Agilent Micro-Gasifier, a heated pressure reducer, is recommended here.

Results and Discussion

The first column channel, a CP-Molsieve 5A, is used to analyze the permanent gases, including hydrogen, oxygen, nitrogen, methane, and carbon monoxide. Figure 2 shows achromatogram for this column channel.

As biogas and related samples may contain larger amounts ofcarbon dioxide, moisture, and higher hydrocarbons it is necessary to backflush these components to maintain theseparation effiency of the Molsieve 5A column. Moisture andcarbon dioxide tend to adsorb quickly to the Molsieve 5A sta-tionary phase and change its chromatographic properties.This would result, over time, in retention shifts and loss ofseparation. Higher hydrocarbons will eventually elute, but willcause higher detector noise levels and lead to reduced sensitivity. The backflush to vent functionality on theMolsieve 5A column channel prevents this from happening.

Table 2 shows excellent repeatability figures for both retention time, below RSD 0.05 %, and peak area below RSD 0.1 %, for the compounds analyzed on the Molsievecolumn channel.

0 30 60 90 120

Seconds

Hydrogen

Oxygen

Nitrogen

Carbonmonoxide

Zoom

Methane

Figure 2. Chromatogram for permanent gases on the CP-Molsieve 5A column channel.

carbon dioxide, ethane, hydrogen sulfide, and propane isobtained, shown in Figure 2. Higher hydrocarbons present inthe sample are backflushed to vent; which prevents late eluting components from interfering in the next analysis.

4

Table 2. Repeatability Figures for Retention Time and Peak Area on the CP-Molsieve Column

Run no.Hydrogen Rt (sec)

Oxygen Rt (sec)

Nitrogen Rt (sec)

Methane area

Hydrogen area

Oxygen area

Nitrogen area

Methane area

1 23.23 30.46 42.31 55.85 5852426 1594746 4855956 15750694

2 23.22 30.46 42.31 55.85 5852402 1594913 4856189 15752646

3 23.22 30.45 42.30 55.85 5849806 1594074 4853402 15749892

4 23.22 30.45 42.30 55.85 5857044 1596055 4859671 15769519

5 23.22 30.46 42.31 55.86 5853222 1595289 4856426 15762840

6 23.23 30.46 42.30 55.85 5847437 1593546 4853332 15742096

7 23.22 30.45 42.30 55.85 5855831 1596512 4860136 15768153

8 23.23 30.46 42.31 55.86 5846434 1594241 4854710 15745279

9 23.22 30.46 42.30 55.85 5860122 1597659 4864955 15785858

10 23.22 30.45 42.30 55.85 5852819 1595989 4860359 15768762

Average 23.22 30.46 42.30 55.85 5852754 1595302 4857514 15759574

Std. dev. 0.0048 0.005 0.005 0.004 4210 1258 3691 13699

RSD (%) 0.021 0.017 0.012 0.008 0.072 0.079 0.076 0.087

For pure biogas, carbon dioxide and hydrogen sulfide are analyzed on a CP-PoraPLOT U column channel. When biogasis mixed with other hydrocarbon streams, ethane and propanecan also be analyzed on this channel. Baseline separation of

10 20 30 40 50 60Seconds

Carbon dioxide

Ethane Hydrogen sulfide

Propane

Hydrogen sulfide

Zoom

Figure 3. Chromatogram for carbon dioxide, hydrogen sulfide, ethane, and propane on the CP-PoraPLOT U channel.

5

The stainless steel tubing in the CP-PoraPLOT U channel andthe sample inlet of the Micro GC have an UltiMetal deactiva-tion layer, which results in an inert sample flow path andbetter performance for hydrogen sulfide analysis. Results pre-sented in Table 3 shows very good repeatability figures forhydrogen sulfide and the other compounds (carbon dioxide,ethane, and n-propane) analyzed on the CP-PoraPLOT U chan-nel. Relative standard deviation (RSD %) below 0.02 % forretention time and below 0.15 % based on area illustrates thesystem’s suitability for this type of analysis. Moreover theUltiMetal deactivated sample inlet tubing provides an excellent peak shape for hydrogen sulfide, see Figure 3.

The CP-Molsieve and CP-PoraPLOT U channel, chromatograms as shown in Figure 3, are part of both theBiogas and Extended Biogas Analyzer.

Table 3. Retention Time and Peak Area Repeatability Results for the CP-PoraPLOT U Column

Run no.

Carbon dioxide Rt (sec)

Ethane Rt (sec)

Hydrogen sulfide Rt (sec)

n-Propane Rt (sec)

Carbon dioxide area

Ethane area

Hydrogen sulfide area

n-Propane area

1 24.56 26.87 34.11 44.80 3240882 2662227 320047 2175181

2 24.56 26.88 34.12 44.80 3239148 2660569 319969 2178315

3 24.56 26.87 34.12 44.80 3240617 2662025 320273 2181300

4 24.56 26.87 34.11 44.79 3239973 2661327 320031 2180366

5 24.56 26.87 34.11 44.79 3239006 2661163 319909 2178141

6 24.56 26.87 34.11 44.80 3240134 2661385 319833 2174648

7 24.55 26.87 34.11 44.79 3239972 2661379 320000 2173550

8 24.55 26.87 34.11 44.79 3238407 2660348 319721 2177678

9 24.56 26.87 34.11 44.79 3238332 2660512 320024 2179891

10 24.55 26.87 34.11 44.79 3237012 2659615 319789 2176390

Average 24.56 26.87 34.11 44.79 3239348 2661055 319960 2177546

Std. dev. 0.0048 0.0032 0.0042 0.0052 1197 797 157 2578

RSD (%) 0.020 0.012 0.012 0.012 0.037 0.030 0.049 0.12

6

In Figure 4, the chromatogram illustrates the separation andquantification of the higher boiling hydrocarbons as part ofthe Extended Biogas Analyzer setup; the column used is aCP-Sil 5 CB. This additional channel expands the applicationrange of biogas analysis to blends with natural gas or liquefied petroleum gas (LPG). In this particular case, thebiogas was mixed with natural gas.

030 60 90

120

Seconds

i

neo-Pentane

Propane

n-Butane

n-Pentane

n-Hexane

i- Pentane

n-Heptane

Zoom

-Butane

Figure 4. Chromatogram on the CP-Sil 5 CB, separating the hydrocarbons from butanes to n-heptane.

Table 4a. Retention Time Reproducibility Data for the CP-Sil 5 CB Channel

Run no.i-Butane Rt (sec)

n-Butane Rt (sec)

neo-Pentane Rt (sec)

n-Pentane Rt (sec)

i-Pentane Rt (sec)

n-Hexane t (sec)

n-Heptane Rt (sec)

1 18.10 20.43 21.75 28.58 32.52 59.67 120.66

2 18.10 20.43 21.75 28.58 32.52 59.67 120.69

3 18.10 20.42 21.74 28.58 32.51 59.66 120.70

4 18.10 20.42 21.74 28.57 32.51 59.66 120.71

5 18.09 20.42 21.74 28.57 32.50 59.64 120.72

6 18.09 20.42 21.74 28.57 32.50 59.64 120.72

7 18.09 20.41 21.73 28.56 32.49 59.63 120.72

8 18.08 20.41 21.72 28.55 32.48 59.61 120.73

9 18.08 20.40 21.72 28.55 32.48 59.60 120.72

10 18.08 20.40 21.72 28.54 32.47 59.59 120.74

Average 18.09 20.42 21.74 28.57 32.50 59.64 120.71

Std. dev. 0.0088 0.0107 0.0118 0.014 0.018 0.029 0.023

RSD (%) 0.048 0.053 0.054 0.050 0.054 0.049 0.019

Tables 4a and 4b show repeatability on the CP-Sil 5 CB channel for the hydrocarbons. The repeatability data ofapproximately 0.05% for retention times and below the 0.2%mark for peak area can be considered as excellent. Even thepartially separated neo-pentane shows a good peak arearepeatability performance.

7

Conclusion

The Agilent 490 Micro GC Biogas Analyzer type requireddepends on biogas sample type. Regular biogas containsmethane, carbon dioxide, nitrogen, and sometimes somehydrogen, hydrogen sulfide, and carbon monoxide. For thistype of sample, the 490 Micro GC Biogas Analyzer is perfectlysuited.

The first column channel, configured with a CP-Molsieve 5Acolumn with argon as carrier gas, will separate and analyzehydrogen, oxygen, nitrogen, methane, and carbon monoxide.Moisture and carbon dioxide, as well as higher hydrocarbonspresent in the sample, are backflushed to vent, ensuring trouble free operation, perfect repeatability, and a longcolumn lifetime without the need for extensive conditioningprocedures. Moreover, this column channel is equipped witha Retention Time Stability option (RTS) to ensure stable retention time on the CP-Molsieve 5A column over time.

The second channel, equipped with a CP-PoraPLOT U column,analyzes carbon dioxide and hydrogen sulfide as part of thebiogas sample. This column can even be used when ethaneand propane are present in the sample. The sample inlet ofthe Micro GC and the CP-PoraPLOT U channel are treatedwith an UltiMetal deactivation process to guaranty good performance for hydrogen sulfide analysis.

When butanes and higher hydrocarbons need to be analyzed,the Agilent 490 Micro GC Biogas Analyzer Extended is recommended. This analyzer, suited for analysis of biogasmixed with other hydrocarbon streams such as natural gas orLPG, is equipped with an additional CP-Sil 5 CB column channel.

All results clearly illustrate that both analyzer configurationsare perfectly capable of analyzing biogas and related samplestreams. Typical repeatability figures show RSD’s around0.05 % for retention time and RSD’s less than 0.2 % for peakarea, while the factory specification for peak area repeatabilityis specified on 0.5% RSD (based on 1 % concentration levelpropane).

The Agilent 490 Micro GC Biogas Analyzers are factory tuned,including the appropriate settings for the backflush times forthe CP-MolSieve 5A and CP-PoraPLOT U columns. The AgilentBiogas Analyzers are shipped with final test data, optimizedanalytical method, Biogas Analyzer User Manual, and a checkout sample kit to have all information available at installation.


These data represent typical results. For more information onour products and services, visit our Web site atwww.agilent.com/chem/microgc.

Table 4b. Reproducibility Data, Based on Peak Area, for the CP-Sil 5 CB Column

Run no.i-Butane area

n-Butane area

neo-Pentanearea

n-Pentane area

i-Pentanearea

n-Hexane area

n-Heptane area

1 7014680 7186850 1265110 2702141 2781533 1552255 133755

2 7018181 7190966 1264813 2703703 2783345 1553847 133682

3 7018469 7187273 1269047 2704327 2783935 1554441 133642

4 7017302 7188209 1269045 2705176 2784640 1554809 133920

5 7017858 7190794 1264914 2705022 2784520 1554963 133951

6 7024447 7196790 1265962 2707439 2787091 1556518 133959

7 7025658 7196118 1269229 2708459 2787981 1557169 133959

8 7019982 7188645 1270146 2706467 2785715 1555951 133880

9 7018355 7189383 1267352 2706536 2785636 1556096 134091

10 7018173 7190297 1266144 2706696 2785947 1555806 134130

Average 7019311 7190533 1267176 2705597 2785034 1555186 133897

Std. dev. 3315 3418 2043 1888 1865 1439 162

RSD (%) 0.047 0.048 0.16 0.070 0.067 0.093 0.12

Data Sheet

Agilent 490 Micro GC BiogasAnalyzers

Key benefits• Complete Solution

The Agilent 490 Micro GC Biogas Analyzers are shipped asa total solution. The analyzers are factory tuned and comewith final test data, analytical method parameters, analyzer user manual and a check-out sample.

• Optimized ConfigurationThe Biogas Analyzers provide the results and ruggednessyou demand in the laboratory or in the field for the analysisof biogas and related sample streams. Agilent provides asingle part number Biogas and Extended Biogas Analyzerdepending on the nature of the sample.

• Ready-to-GoStart-up is easy; the analyzer ships fully loaded with amethod and is ready-to-go upon installation.

• Easy to OperateAgilent’s 490 Micro GC is designed to achieve the bestpossible results. In addition, this system does not require ahigh degree of operator skills to be used successfully.

• The Speed You NeedMicro GC is all about fast chromatography. Precise gasanalysis in seconds rather than minutes provides improvedproduct quality and more exact product valuation.

• Fast DeliveryThe Agilent Biogas Analyzers are shipped from stockensuring short delivery times.

IntroductionBiogas is produced through biological processes such asanaerobic fermentation or digestion of organic material. Themain components of biogas are methane and carbon dioxide,with some other permanent gases, hydrogen and hydrogensulfide. The exact composition of the biogas is related to theorigin of the organic material.

Biogas is considered a renewable and sustainable energysource; it can fuel any type of heat engine to generate eithermechanical or electrical power. To increase its caloric values,it is sometimes necessary to remove some of the carbondioxide or blend it with other hydrocarbon streams.

The increasing interest in biogas results in a growing demandfor fast and efficient analysis technology to determine itscomposition. That is where the Agilent 490 Micro GC BiogasAnalyzers can play a significant role.

2

Choose the right Biogas Analyzer for yourneedsDepending on the composition of your biogas sample, Agilenthas two 490 Micro GC based Biogas Analyzer configurationsavailable.

For pure biogas analysis, including permanent gases andhydrogen sulfide, the Agilent 490 Micro GC Biogas Analyzeris recommended; even ethane and propane can be can beanalyzed with this analyzer setup. This Biogas Analyzer consists of a dual channel cabinet including a 10-meterCP-Molsieve 5A with argon as carrier gas, providing excellentsensitivity and linearity for hydrogen, and a 10-meterCP-PoraPLOT U column channel with helium carrier gas.

When biogas is mixed with other hydrocarbon streams suchas natural gas or liquefied petroleum gas (LPG), the samplecontains higher boiling hydrocarbons. To analyze thesehydrocarbons, the Agilent 490 Micro GC Biogas AnalyzerExtended is the analyzer of choice. This Extended BiogasAnalyzer is a quad channel cabinet Micro GC including threecolumn channels; a 10-meter CP-Molsieve column on argonas carrier gas, a 10-meter CP-PoraPLOT U column, and anadditional 6-meter CP-Sil 5 CB column on helium as carriergas.

Both Biogas Analyzers are equipped with heated samplelines and injectors to eliminate any cold spot and preventpossible condensation of moisture, to ensure the integrity ofthe sample is maintained throughout the sample flow path.

The CP-Molsieve 5A and CP-PoraPLOT U columns areequipped with backflush to vent functionality. For theMolsieve column, this backflush to vent is required to main-tain the separation effiency as biogas and related samplesmay contain larger amounts of carbon dioxide, moisture, andhigher boiling hydrocarbons. Moisture and carbon dioxidetend to adsorb quickly to the Molsieve 5A stationary phaseand change its chromatographic properties. This wouldresults, over time, in retention shifts and loss of separation.Higher hydrocarbons will eventually elute, but will causehigher detector noise levels and would lead to reduced sensi-tivity. The backflush to vent functionality on the Molsieve 5Aand PoraPLOT U column channel prevents this from happening.

Moreover the CP-Molsieve 5A is equipped with the retentiontime stability (RTS) option. This RTS option consists of addi-tional in-line filters between the electronic gas control andthe column module to ensure moisture and carbon dioxidefree carrier gas. Moreover the use of the RTS option enablesa more efficient backflush of carbon dioxide. This enhancescolumn lifetime and, most importantly, leads to more stableretention times.

Channel 1 – Permanent gases

Channel 2 – CO2, C2, H

2S, and C3

0 30 60 90 120

Seconds

Hydrogen

Oxygen

Nitrogen

Carbon monoxide

Methane

10 20 30 40 50 60Seconds

Carbon dioxide

Ethane

Hydrogen sulfide

PropaneZoom

Zoom

Channel 3 – C4 – C7 hydrocarbons

0 30 60 90 120

Seconds

i-Butane

neo-Pentane

n-Butane

n-Pentane

n-Hexane

i-Pentane n-Heptane

Zoom

3

Technical specification

AccessoriesThe table below gives an overview of the most importantAgilent 490 Micro GC Biogas Analyzer compatible accessories.Contact your local Agilent office for more details and accessories.

Analyzer characteristics Agilent 490 Micro GC Biogas Analyzer Agilent 490 Micro GC Biogas Analyzer Extended

Micro GC cabinet Dual Quad

Number of column channels 2 3

CP-MolSieve 5A column channel with backflush and retention time stability (RTS)

with backflush and retention time stability (RTS)

CP-PoraPLOT U column channel with backflush with backflush

CP-Sil 5 CB column channel –

All channels equipped with heated injectors (up to 110 °C)

Dual Carrier gas; Argon on Molsieve 5A, Helium on otherchannels

Sample inlet UltiMetal treated

Heated sample line (up to 110 °C)

O2/ N2 separation

CO and CO2 analysis

H2S analysis

CH4, C2, and C3 hydrocarbon analysis

C4, C5, C6, and C7 hydrocarbon analysis –

Sample type biogasbiogas and biogas mixed with other hydrocarbonstreams (natural gas or LPG)1

Typical peak area repeatability (RSD%) < 0.5 % < 0.5 %

Analysis time < 120 seconds < 150 seconds

Note 1: To introduce of a Liquefied Natural Gas (LNG) or Liquefied Petroleum Gas (LPG) sample on the Micro GC, the use of the Micro-Gasifier is required.

Product description Compatible with Part number

Portable field case for a dual channel cabinet and dual carrier gases Agilent 490 Micro GC Biogas Analyzer CP490242

Portable field case for a quad channel cabinet and dual carrier gases Agilent 490 Micro GC Biogas Analyzer Extended CP490252

Micro-Gasifier Both Biogas Analyzers G7623A#001

Genie filter Both Biogas Analyzers Multiple p/n’s


Agilent shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.

Information, descriptions, and specifications in this publication are subject to change with-out notice.

© Agilent Technologies, Inc., 2011Published in USA, November 29, 20115990-9517EN

Dimensions and weight

Ordering informationThe Agilent Biogas Analyzers can be purchased by ordering

the main part number G3582A and an option number per

analyzer type; option numbers for the Biogas Analyzers are

displayed below.

Height Width Depth Weight

Product description inch cm inch cm inch cm lb kg

Agilent 490 Micro GC Biogas Analyzer 11 28 6.5 16 12 30 14 6

Agilent 490 Micro GC Biogas Analyzer Extended 11 28 6.5 16 21.5 55 22 10

Micro GC Power Supply 1.8 4.5 3.4 8.5 6.7 17 3.3 1.5

Product description Part number

Agilent 490 Micro GC Analyzer G3582A

Agilent 490 Micro GC Biogas Analyzer G3582A#110

Agilent 490 Micro GC Biogas Analyzer Extended G3582A#111

Analysis of Biogas with the 490 Micro GC Gas Chromatograph

Application Note

IntroductionBiogas is a gas mixture produced by biological processes, from the anaerobic fermentation of organic material such as biomass, manure or sewage, municipal waste, green waste and energy crops. Swamp gas is a naturally produced biogas.

The main components of biogas are methane and carbon dioxide, with some carbon monoxide and hydrogen. Biogas can be used as biofuel, as a low-cost fuel for any heating purpose. It also has a role in modern waste management to run any type of heat engine, to generate either mechanical or electrical power. To increase caloric values it might be necessary to remove some of the carbon dioxide. Biogas can be compressed, much like liquified natural gas, and used to power motor vehicles. For this purpose it is necessary to remove hydrogen sulfide. Biogas is a renewable fuel, and so it qualifies for renewable energy subsidies in some parts of the world. Due to the increasing interest in biogas, there is a growing demand for fast and efficient analysis technology. That is where the new generation micro GC from Agilent, the 490 Micro GC, can play a significant role.

AuthorsCoen DuvekotAgilent Technologies, Inc.

2

InstrumentationDepending on the type of biogas to be analyzed, two configurations are available. If the sample contains only permanent gases and the hydrocarbons methane, ethane and propane, a dual channel GC is ideal. If higher hydrocarbons are also present in the sample, a third channel is needed and therefore the quad version of the micro-GC is recommended.

490 Micro GC Gas Chromatograph

Dual channel:

• Channel 1, CP-Molsieve column

• Channel 2, CP-PoraPLOT U column

Quad equipped with three channels:

• Channel 1, CP-Molsieve column

• Channel 2, CP-PoraPLOT U column

• Channel 3, CP-Sil 5 CB column

GC control and data handling software: Galaxie Chromatography Data System

ConditionsTable 1. GC conditions

Inj Time (ms)

Inj Temp (° C)

Column Temp (° C)

Carrier Gas Pressure (kPa)

Back Flush (sec)

Ch1 40 80 80 Ar 150 9Ch2 100 80 100 He 100 10Ch3 100 80 60 He 150 -

Results and DiscussionThe sample can be introduced to the 490 Micro GC either pressurized (reduced to max 1 bar) via a Tedlar sampling bag, or by using continuous flow. In this case the sample was pressurized, see Figure 1. 0.4 2min

12

3

4KEY1. H22. O23. N24. CH4

Figure 1. Permanent gases on the CP-Molsieve channel

As biogas and related samples may contain large amounts of CO2, water and higher hydrocarbons it was necessary to back flush these components. Water and CO2, in particular, adsorb to the stationary phase and change chromatographic properties. Higher hydrocarbons eventually elute but cause higher noise and thus reduced sensitivity.

An indication of changed chromatographic properties is a drift in retention time. Table 2 shows repeatability figures on the CP-Molsieve channel. Repeatability figures of retention time and quantity are presented.

3

Table 2. Repeatability figures for the CP-Molsieve channel

Run # Tr (min) Hydrogen

Tr (min) Oxygen

Tr (min)Nitrogen

Tr (min)Methane

QTY (%)Hydrogen

QTY (%) Oxygen

QTY (%) Nitrogen

QTY (%)Methane

123456789101112131415

0.50950.50970.5090.50950.50950.50950.50970.50920.50950.50980.50930.50920.50920.50970.5092

0.68580.68580.68520.68570.68580.68580.6860.68530.68580.68620.68550.68550.68550.6860.6853

0.96180.9620.9610.96170.96220.9620.96220.96170.9620.96230.96170.96150.96170.96220.9615

1.27451.27481.27271.27431.27481.27431.27481.27351.27451.27531.27361.27351.27371.27521.2735

1.02531.02221.03751.02391.02921.03291.03061.03651.02781.02521.03471.03981.03681.02641.0361

2.01832.0122.02722.01552.01972.02582.02542.03032.01882.01652.02772.03582.0322.01432.0294

8.05118.0578.08748.03078.05168.06648.05898.08758.04468.01828.07548.0998.07978.00828.0688

84.510782.94588.320783.286985.447586.78785.207388.318285.398183.020287.397688.166887.191682.840987.3486

Average Std Dev RSD %

0.50940.00020.05%

0.68570.00030.04%

0.96180.00030.04%

1.27420.00070.06%

1.03100.00570.55%

2.02320.00730.36%

8.05690.02740.34%

85.74582.05922.40%

The very low relative standard deviation (RSD%) figures in Table 2 clearly show that the CP-Molsieve channel was working with very good repeatability. There was no drift in retention time and the analysis results for quantity were also very repeatable.

Figure 2 shows the chromatogram of the CP-PoraPLOT U channel. Separation of carbon dioxide, ethane, hydrogen sulfide and propane was achieved.

Baseline separation of all components of interest was obtained. Higher hydrocarbons were back flushed to vent, which prevented later eluting components from disturbing the next analysis. The results presented in Table 3 show very good repeatability figures for the CP-PoraPLOT U channel. RSD% below 0.1% for retention times and quantification illustrate the system’s suitability for this type of analysis.

0.3 1min

1

2

3

4

KEY1. Composite air peak2. CO23. Ethane4. H2S5. Propane

5

Figure 2. CO2, H2S, ethane and propane on the CP-PoraPLOT U channel

4

Table 3. Repeatability figures of the CP-PoraPLOT U channel

Run # Tr (min) Air Peak

Tr (min) CO2

Tr (min)Ethane

Tr (min)Propane

QTY (%)CO2

QTY (%) Ethane

QTY (%) Propane

123456789101112131415

0.41150.41130.41170.41170.41150.41150.41150.41130.41150.41150.41150.41150.41130.41130.4118

0.45220.4520.45250.45250.45220.45230.45220.45220.45220.45220.45220.45220.45220.4520.4525

0.48330.48320.48370.48370.48330.48350.48350.48330.48330.48330.48330.48330.48330.48320.4837

0.68080.68070.68150.68130.68080.6810.68080.68080.68080.68080.68080.68070.68070.68070.6815

1.98661.9881.99211.991.99211.9911.98961.99081.99271.99121.99331.99271.99081.99281.9919

4.00324.00484.01214.00734.0114.00894.00594.00734.0114.00694.01134.01034.00624.00964.0076

2.99552.99673.00152.99853.00142.99922.99732.99863.00272.99843.00183.00082.99782.99942.9992

Finally, Figure 3 is a chromatogram of the separation and determination of the (higher) hydrocarbons. The column used was a CP-Sil 5 CB. This extra channel expanded the application range of biogas analysis to blends with C3 and or C4 LPGs.

Figure 3. Higher hydrocarbons on the CP-Sil 5 CB channel

0.2 1.6min

1

2 3 4

5 6 7

KEY1. H2S2. Propane3. iso-Butane4. n-Butane5. iso-Pentane6. n-Pentane7. n-Hexane

Table 4 shows the repeatability figures of the CP-Sil 5 CB channel. Again, very good repeatability figures were obtained. Relative standard deviation was well below 0.05% for retention times and below 0.15% for quantitative measurements.

www.agilent.com/chemThis information is subject to change without notice.© Agilent Technologies, Inc. 2010Published in UK, August 19, 2010SI-02215

Table 4. Repeatability figures of the CP-Sil 5 CB channel

Run # Tr (min) Air Peak

Tr (min) Ethane

Tr (min)Propane

Tr (min)iso-Butane

Tr (min)n-Butane

QTY (%) Ethane

QTY (%) Propane

QTY (%) iso-Butane

QTY (%) n-Butane

123456789101112131415

0.30250.30230.30230.30230.30220.30230.30230.30220.30230.30230.30230.30230.30220.30220.3022

0.33330.33330.33330.33320.33320.33320.33320.33320.33320.33320.33320.33320.3330.3330.333

0.38330.38330.38320.38320.3830.38320.38320.3830.38320.38320.38320.38320.3830.3830.383

0.4550.4550.4550.45480.45470.45470.45480.45470.45480.45480.45480.45480.45470.45470.4547

0.51070.51050.51050.51030.51020.51020.51030.51020.51030.51030.51030.51030.51020.51020.5102

4.01084.00924.01394.01164.01294.00964.01024.01264.01194.00984.01124.00914.01284.00994.0098

3.02223.01793.01713.01363.01313.01113.00953.01043.0093.0093.00923.00783.01013.00833.0083

0.5010.5010.50070.50090.50070.50070.50060.50090.50070.50090.50110.50080.50140.5010.5009

0.50050.50040.50020.50030.50040.50030.50020.50040.50030.50030.50050.50.50070.50030.5002

Average Std Dev RSD %

0.30230.00010.03%

0.33320.00010.03%

0.38310.00010.03%

0.45480.00010.02%

0.51030.00010.03%

4.01100.00150.04%

3.01180.00420.14%

0.50090.00020.04%

0.50030.00020.03%

490 Micro GC Configuration for Biogas depends on Sample TypeRegular biogas contains methane, oxygen, nitrogen, carbon dioxide, hydrogen sulfide, and sometimes some hydrogen and carbon monoxide. For this type of sample a two channel 490 Micro GC is perfectly suited. Channel 1, configured with a CP-Molsieve column, will separate and analyze hydrogen, oxygen, nitrogen, methane and carbon monoxide. Channel 2, equipped with a CP-PoraPLOT U column, will analyze carbon dioxide and hydrogen sulfide. This configuration can even be used if ethane and propane are present in the sample. If, however, C4+ hydrocarbons also have to be analyzed, a third CP-Sil 5 CB channel is required, together with the 490 Micro GC QUAD.

ConclusionAll results clearly showed that the system configuration was perfectly capable of analyzing biogas.

The CP-Molsieve channel separated and analyzed permanent gases such as hydrogen, oxygen, nitrogen and methane. With some changes in chromatographic parameters even carbon monoxide can be analyzed on this channel. Higher hydrocarbons, as well as moisture and carbon dioxide, were back flushed to vent ensuring trouble free operation, perfect repeatability and a long column lifetime.

Using the Agilent 490 Micro GC for theMonitoring of a Circulating Fluidized BedBiomass Gasifier

Author

Marcin Siedlecki

Energy Technology Section

Process and Energy Department

Delft University of Technology

Delft, The Netherlands

Remko van Loon


Middelburg, The Netherlands

Application Note

Micro Gas Chromatography, Reaction/Production Monitoring,Renewable Energy

Abstract

Biomass has been recognized as a potential renewable and sustainable energy

source. The Delft University of Technology researches the gasification of woody and

agricultural biomass in a Circulating Fluidized Bed Reactor. The Agilent 490 Micro GC

is used to characterize the product gas using a COX column for the permanent gases

and a CP-Sil 5CB for the BTX compounds.

Introduction

There is a growing interest in sustainable heat and power generation using biomass.A possible way to use the biomass is through thermal conversion processes; com-bustion and gasification are the most well-known examples. The Process and EnergyDepartment of the Delft University of Technology researched the gasification ofwoody and agricultural biomass in a Circulating Fluidized Bed. The product gas con-sists roughly of 5–15% Carbon monoxide, 10–15% Hydrogen, 3–5% Methane,10–20% Carbon dioxide, 5–10% Nitrogen, and 40–70% Water, also (poly)aromaticcompounds, minor inorganic species, and particles are present in the gas.

This product gas can be subsequently upgraded to Syngas (a mixture of Hydrogen,Carbon monoxide, Carbon dioxide and eventually water vapor). After applying thewater-gas shift reaction (CO + H2O & CO2 + H2), Syngas could be used as a hydro-gen-rich fuel gas for Fuel Cells. Other applications of Syngas are Fisher Tropschprocesses (Gas to Liquid fuels), platform chemicals (like furfural), or the combustionin a gas turbine to generate heat and power. For the characterization of the productgas, the Agilent 490 Micro GC was used.

Figure 1. Reactor, sampling and sample conditioning setup.

2

Experimental

Fluidization media and woody or agricultural biomass are fedinto the Circulating Fluidized Bed Reactor, where the biomassis gasified at around 850 °C. The sample is taken from theproduct gas stream using a heated probe. Particles present inthe sample are removed by the dust filter. Water vapor isstripped from the sample using two condensers. Figure 1gives an overview of the sampling and sample conditioningsetup. An external gas pump provides a continuous samplegas flow to the Agilent Micro GC. Every 3 min, theMicro GC starts an analytical run and analyses the gassample on both column channels.

The Agilent 490 Micro GC used for the analysis of theproduct gas is equipped with a 1 m COX column channel forpermanent gas analysis and a 4 m CP-Sil 5 CB columnchannel for the analysis of Benzene, Toluene and the Xylenes.The Micro GC conditions for both channels are displayed inTable 1.

1 m COX 4 m CP-Sil 5 CB

Column temperature 100 °C 100 °CCarrier gas Argon, 200 kPa Argon, 150 kPaInjector temperature 110 °C 110 °CInjection time 20 ms 40 msDetector sensitivity Auto HighSample line temperature 110 °CSampling mode Continuous flowSampling time 10 s

Figure 2. Permanent gases on the COX column.

Table 1. Agilent 490 Micro GC Instrument Conditions

Results and Discussion

The COX column shows an excellent separation for the permanent gases, as shown in Figure 2.

3

Although the COX column does not separate oxygen andnitrogen, it is very suitable for the analysis of permanentgases including carbon dioxide. In the case of gasification, theproduct gas sample does not contain oxygen. When thesample contains both oxygen and nitrogen, and these gasesneed to be quantified separately, the use of a MolSieve5Acolumn channel instead of the COX column channel isrequired. The COX column can be equipped with a back flushto vent. This option makes it possible to back flush later elut-ing compounds to reduce analysis time and to prolong columnlifetime.

For each component a multi-level calibration (4 levels) is per-

formed. Figures 3 and 4 show an excellent calibration curvefor Methane and Carbon monoxide. For a linear regression,the R-Squared for these compounds is nearly perfect.

The BTX compounds are analyzed on a CP-Sil 5 CB columnchannel. The chromatogram in Figure 5 shows that all com-pounds are eluted in less than 90 sec. On the CP-Sil 5 CBcolumn type it is not possible to separate meta- andpara-Xylene. These compounds are reported in a single result.For all BTX compounds, a 4-level calibration is performed.Figure 6 shows an example of Benzene. R-squared (linearregression) for Benzene is 0.9969.

Figure 3. Calibration curve for methane.

900

800

700

600

500

Are

a

400

300

200

100

00 5 10

Concentration (vol %)15

Methane

R2=0.9999800

700

600

500

Are

a

400

300

200

100

00 10 20

Concentration (vol %)30 40 50

Carbon Monoxide

R2=0.9998

Figure 4. Calibration curve for Carbon monoxide.

Figure 5. BTX analysis on the CP-Sil 5 CB column.





500,000

450,000

400,000

350,000

300,000

Are

a

250,000

200,000

150,000

100,000

50,000

00 42 6 8

Concentration (vol %)10

Benzene

R2=0.9969

Figure 6. Calibration curve for Benzene.

Conclusion

The data presented in this application note clearly shows thatthe Agilent 490 Micro GC equipped with two column channelswas capable of monitoring the product gas from theCirculating Fluidized Bed biomass gasifier. Within180 sec the permanent gases were analyzed using a COX column channel. The BTX analysis was performed on aCP-Sil 5CB column channel with an analysis time of less than90 sec.

The Agilent 490 Micro GC is considered a key apparatus forthe quantification of the main product gas components in thegasification test rig at the Process & Energy Laboratory at

Delft University of Technology. The main advantages of the490 Micro GC analyzer are its reliability, short analysis times,ease of use (both hardware and software), and a certaindegree of flexibility. The modular setup of the 490 Micro GCmakes it possible to exchange the column modules if othergas components need to be analyzed.

The Agilent 490 Micro GC is a rugged, compact and portablelab-quality gas analysis platform. When the composition ofgas mixtures is critical, count on this fifth generation microgas chromatograph.

References

1. M.Siedlecki, R. Nieuwstraten, E. Simone, W. de Jong andA.H.M. Verkooijen; Delft University of Technology; ‘Effectof Magnesite as Bed Material in a 100 kWth Steam-Oxygen Blown Circulating Fluidized-Bed Biomass Gasifieron Gas Composition and Tar Formation’; 2009.

2. Application note 5990-7054EN; Simone Darphorn-Hooijschuur and Marijn van Harmelen, AvantiumTechnologies; Remko van Loon and Coen Duvekot, AgilentTechnologies; ‘Permanent Gases on a COX Module Usingan Agilent 490 Micro GC’; 2010.



BIOGAS Analyser S

ER

VIC

E M

ER

GE

S Q

UA

LIT

Y

Flow Pressure Connection Grade / Purity1 Dewpoint

Sample gas Minimum 12 ml/min 0 - 1 barG 1/8" OD - Non condensing

1/16" OD 0 - 110°C

Carrier gas

Argon 16 ml/min 5,5±0,1 barG 1/8" OD 4.8 / 99,998% < -30°C

Helium 16 ml/min 5,5±0,1 barG 1/8" OD 4.8 / 99,998% < -30°C

Hydrogen 16 ml/min 5,5±0,1 barG 1/8" OD 4.8 / 99,998% < -30°C

Nitrogen 16 ml/min 5,5±0,1 barG 1/8" OD 4.8 / 99,998% < -30°C

BIOGAS analyser Specifications Model 490-GC

Configuration: one plug- and-play GC

channel Control:

control for the BIO gas channel with its separate pneumatics, injector, column and detector.

Control of max two stream. One process stream and one calibration stream

Injector

Micro-machined injector with no moving parts

Injection volume:1µl to 10µl, software selectable

Optional heated injector: 30°C to 110°C, including heated transfer line

Column Oven

Temperature range: 30°C to 180°C, isothermal

Optional backflush capability

All capillary columns available Control/Data Handling Software

Standard packag Pro Software

Regulatory compliance and reports: meet requirements, particularly for the natural gas and petrochemical industries

Special packages: ISOCAL and BTU for natural (BIO) gas properties, such as calorific value and relative density, meet ISO 6976, GPA 2171, and ASTM D 3588 standards

TCD Detector

Detection Limits

WCOT columns: 1ppm

Micro-packed columns: 10ppm Operating Range

Concentration: 1ppm to 100% level

Linear dynamic range: 106

Repeatability:

<0.5% RSD for propane at 1 mol % level for WCOT columns at constant temperature and pressure

Environmental Requirements

Humidity (relative): 0% to 95% non-condensing

Temperature 0°C to 30°C in a controlled atmosphere

Dimensions and Weight

Enclosure material Aluminium

280 mm (W) x 150 mm (D) x 300 mm (H)

Weight: 5.2 kg

Analytical Solutions and Products B.V. Distelweg 80m ● Amsterdam

P.O. box 37146 ● 1030 AC ● Amsterdam Tel. +31 (0)20 49 24 748 ● E-mail [email protected]

Fax. +31 (0)20 33 72 798 ● homepage www.asap4u.nl

Power Requirements

Main power: 12 VAC

Opt: 100-240 VAC 50-60 Hz

Power consumption: 130 Watt Communication

Ethernet TCP/IP with static IP address

RS-232

Optional: Com port for external devices, selectable RS-232 or RS-485

Optional: fibre optic modem

Optional: gsm/gprs modem

Optional: wireless TCP/IP

Optional: 4-20 mA outputs

Optional: digital outputs Hazardous Area Classification

ATEX Zone 2

II 3G Ex nA IIC T3

BIOGAS Analyser S

ER

VIC

E M

ER

GE

S Q

UA

LIT

Y

Analytical Solutions and Products B.V. Distelweg 80m ● Amsterdam

P.O. box 37146 ● 1030 AC ● Amsterdam Tel. +31 (0)20 49 24 748 ● E-mail [email protected]

Fax. +31 (0)20 33 72 798 ● homepage www.asap4u.nl

CO2 analyser Infrared Smart gas sensor Measuring principle: Non Dispersive Infra-Red (NDIR), dual wavelength

Measurement range: 0-100 % CO2 in CH4 Gas supply: flow through cell Gas line connectors: 3 mm internal, 5 mm outer diameter Flow rate: 0.2 to 0.8 l/min (constant) Dimensions: Length (model dependent) x 28 mm x 42 mm (L x W x H) Warm-up time: < 2 minutes (start up time) < 30 minutes (full specification) Measuring response

(2)

Response time (t90): Appr. 15 s (@ 0.5 l/min) (1)

Digital resolution (@ zero): 1 ppm / 0.1 % LEL / 0.01 Vol.-% / 0.1 Vol.-%

(1)

Detection Limit (3s): ≤ 1 % FS (3)

(typically) Repeatability: ≤ +/- 1 % FS(3) Linearity error

(4): ≤ +/- 2 % FS

(3)

Long term stability (zero) (5)

: ≤ +/- 2 % FS (3)

over 12 month period Long term stability (span) (

5): ≤ +/- 2 % FS

(3) over 12 month period

Influencing variable

(6)

Temp. dependence (zero): ≤ +/- 0.1 % FS (3)

per °C Temp. dependence (span): ≤ +/- 0.2 % FS

(3) per °C

Pressure dependence (zero): - Pressure dependence (span): 0.1 % to 0.2 % value per hPa

(1)

Electrical inputs and outputs

Supply voltage: 6 V DC +/- 5 % Supply current: 70 mA average, max. 140 mA Power consumption: < 1 Watt Outputs

Digital output signal: Modbus ASCII via UART Calibration: zero and span by SW Climatic conditions

Operating temperature: -10 °C to 40 °C Storage temperature: -20 °C to 60 °C Air pressure: 800 to 1200 hPa Humidity: 0 % to 95 % rel. humidity (not condensing) 1)

Dependent on the gas and the measurement range 2) Relating to sample gas pressure 1013 hPa absolute, 0.5 l/min gas flow and 25°C ambient and gas

temperature 3) FS = Full scale 4) Stated linearity error excludes calibration gas tolerance of ± 2 % 5) For dry and clean test gas at 25°C and 1013hPa absolute - depending on the operating and ambient

conditions values may differ 6) Relating to calibration conditions (see final check)

Fast Refinery Gas Analysis Using the 490 Micro GC QUAD

Application Note

IntroductionThere is a large variation in the composition and source of refinery gases. Therefore, the precise and accurate analysis of these gases is a significant challenge in today’s refineries. Typical sources include fluid coking overheads, ethylene, propylene, fuel gas, stack gas, off gas, etc. The physical stream ranges from gas to highly pressurized gas or liquid.

Very fast refinery gas analysis (RGA) is possible with the portable 490 Micro GC QUAD. This note describes the use of the 490 Micro GC for RGA, with results obtained in about two minutes.

AuthorsCoen DuvekotAgilent Technologies, Inc.

2

Results and DiscussionFigures 1 and 2 show chromatograms of the Molsieve channel 1.

Instrumentation490 Micro GC QUAD

• Channel 1: Molsieve with back flush

• Channel 2: CP-PoraPlot U with back flush

• Channel 3: Aluminium oxide with back flush

• Channel 4: CP-Sil 5 CB

The Molsieve channel and the aluminium oxide channel are equipped with extra in-line filters between the manifold and the column module to ensure moisture and carbon-dioxide-free carrier gas. This enhances column lifetime and, most importantly, leads to stable retention times.

GC control and data handling software: Galaxie Chromatography Software.

Materials and ReagentsChannel 1, equipped with a Molsieve column, separates and analyzes the permanent gases except for carbon dioxide. Channel 2, with a CP-PoraPLOT U column, separates and analyzes the C2 gases and hydrogen sulfide. The C3 and C4 hydrocarbons are analyzed on the third channel with an Al2O3 column. Finally, the higher hydrocarbons are analyzed on the fourth channel, with a CP-Sil 5 CB column.Table 1. Peak identification and composition of gas standards

Gas StandardPeak #

Component Amt (%)

13456

HydrogenOxygenNitrogenMethaneCarbon monoxide

Bal

25 120

1

2

3

4

25 120Sec

4

32

1

Figure 1. Standard gas on the Molsieve column, channel 1

25 120Sec25 120

Sec

2

4

5

6

2

4

5

6

80 105Sec

6

Sec80 105

6

Figure 2. Refinery gas on the Molsieve column, channel 1

Hydrogen or helium, oxygen, nitrogen methane and carbon monoxide were separated and analyzed. Later eluting components were back flushed to vent.

Refinery Gas standard

Peak #

Component Amt (%) Peak # Component Amt (%)

24567891011121314

HeliumNitrogenMethaneCarbon monoxideCarbon dioxideEthyleneEthaneAcetyleneHydrogen sulfidePropanePropyleneiso-Butane

Bal5.124.91.00.524.95.01.01.015.05.00.5

1516171819202122232425

Propadienen-Butanetr-2-Butylene1-Butyleneiso-Butylenecis-2-Butyleneiso-PentaneMethyl acetylenen-Pentane1, 3-Butadienen-Hexane

0.621.00.50.51.010.50.51.00.21.00.2

Channel 1 Channel 2 Channel 3 Channel 410 m Molsieve

10 m CP-PoraPLOT U

10 m Al2O3/KCL

8 m CP-Sil 5 CB

Injector Temp (°C) 110 110 110 110Column Temp (°C) 80 100 100 80Carrier Gas Argon Helium Helium HeliumColumn Head Pressure (kPa) 150 205 70 205Injection Time (ms) 40 10 10 100Back Flush Time (s) 11 7.1 33 N/A

Conditions

Table 2. Chromatographic conditions

3

Sec20 30 4010 20 30 40

7

8

910

11

Sec.10

7

8

9 10

11

Figure 3. Refinery gas on the CP-PoraPLOT U column, channel 2

On the CP-PoraPLOT U channel (channel 2), the C2 hydrocarbons, hydrogen sulfide and carbon dioxide were separated and analyzed. The channel was equipped with a back flush later eluting components to vent.

40 60 80 100 120Sec.

12 13

1014

15

16

17 18

19

2021

22

23

24

Sec120100806040

12 13

1015

16

17 18

19

20 2122

23

24

Figure 4. Refinery gas on the aluminium oxide column, channel 3

14

On channel 2 the C3 and C4 saturated and unsaturated hydrocarbons were separated and analyzed. This channel was also equipped with back flush in order to prevent the later eluting hydrocarbons from entering the analytical column. This prevented the later eluting components from interfering with the next analysis causing “ghost” peaks and/or baseline drift and higher noise. Furthermore, this channel was equipped with extra filters in the carrier gas lines, effectively protecting the analytical column from traces of moisture and carbon dioxide that could influence the chromatographic properties of the stationary phase in the long term.

Stable retention times are key factors for good chromatographic results. Repeatability results derived from Table 3 and Figure 5 for retention times are superb with RSDs around 0.1% and no drift.

4

1

1.5

2

0 5 10 15 20 25 30Run #

Tr (m

in)

tr-2-Butylene1-Butyleneiso-Butylenecis-2-Butyleneiso-PentaneMethyl acetylene2,3-Butadiene

0 10 15 20 25 305

Tr (m

in)

1.5

2

Figure 5. Repeatability figures for the aluminium oxide channel, channel 3

Table 3. Repeatability figures for the aluminium oxide channel

Run # Tr (min)tr-2-Butylene

Tr (min)1-Butylene

Tr (min)iso-Butylene

Tr (min)cis-2-Butylene

Tr (min)iso-Pentane

Tr (min)Methyl acetylene

Tr (min)2, 3-Butadiene

123456789101112131415161718192021222324252627282930

1.26721.2661.26571.26471.26471.2651.26481.26531.26531.26471.2651.26671.26581.26551.26551.26581.26531.26571.26571.26551.26631.26671.26721.26671.26751.26781.26831.26851.26821.2685

1.29631.29521.29481.29381.29371.29421.29381.29431.29431.29381.2941.29581.29481.29451.29471.2951.29451.29481.29471.29471.29531.29581.29631.29581.29671.29681.29751.29751.29731.2977

1.3661.36471.36431.36321.36331.36331.36321.3641.36381.36331.36331.36531.36431.36381.3641.36451.36381.36421.36421.3641.36481.36531.3661.36551.36621.36671.3671.36731.36681.3673

1.44471.44371.4431.4421.4421.44231.4421.44271.44231.4421.44221.4441.44321.44271.44281.44321.44251.4431.4431.44281.44351.44431.44481.44431.4451.44551.4461.44621.4461.4462

1.77971.77721.77681.77551.77581.77571.77531.77631.7761.77531.77521.7781.77681.77621.77631.77681.7761.77651.77651.77621.77751.77821.77931.77821.77881.77981.78071.78031.78021.781

1.9341.93221.93231.9311.9311.93151.93031.9311.93081.93051.93031.93371.93221.93221.93221.93251.93151.93221.93121.9321.93281.9341.93531.93381.93431.93571.9361.9361.93671.9367

2.01552.01222.01152.00972.01022.01022.00922.01052.01082.00952.00982.01282.01172.01082.0112.01152.01072.0112.01082.01082.0122.01332.01452.0132.01382.0152.01622.01582.0162.0163

Average Std Dev Rsd %

1.26620.00120.10%

1.29530.00120.09%

1.36480.00130.10%

1.44360.00140.10%

1.77740.00180.10%

1.93290.00200.10%

2.01220.00220.11%

Run #

5

Day tr-2-Butylene 1-Butylene iso-Butylene cis-2-Butylene iso-Pentane Methyl acetylene 2, 3-Butadiene12348910

1.26951.26781.26681.26651.26971.26811.2667

1.29881.29701.29581.29561.29891.29731.2957

1.36871.36681.36541.36521.36891.36711.3655

1.44811.44581.44431.44391.44831.44621.4443

1.78491.78151.77871.77811.78541.78211.7785

1.94061.93701.93391.93331.94051.93671.9345

2.02162.01732.01372.01302.02222.01802.0139

AverageSt. dev.RSD

1.26790.00130.10%

1.29700.00140.11%

1.36680.00150.11%

1.44580.00180.13%

1.78130.00310.17%

1.93660.00300.15%

2.01710.00370.19%

Table 4. Reproducibility figures

1.0

1.5

2.0

0 5 10Analysis Day

Tr (m

in)

tr-2-Butylene1-Butyleneiso-Butylenecis-2-Butyleneiso-PentaneMethyl acetylene2,3-Butadiene

Figure 6. Reproducibility of the aluminium oxide channel, channel 3

Tr (m

in)

0 5Analysis Day

10

1.5

1.0

2.0

Table 4 and Figure 6 show the effects over several days. RSDs are only slightly higher when compared to the “results-per-day” which is to be expected. However, the results are very good, demonstrating the suitability of the Al2O3 channel for this type of analysis.

RSDs below 0.2% are shown in Table 4. During the ten day laboratory experiments no drift in retention times were observed, as can be seen in Figure 6.

Figure 6 shows no drift in retention time of components analyzed on the Al2O3 channel over ten days.

Figure 7 shows a chromatogram of refinery gas on the CP-Sil 5 CB channel. In this case the higher hydrocarbons C5+ were analyzed.

www.agilent.com/chemThis information is subject to change without notice.

© Agilent Technologies, Inc. 2010Published in UK, August 03, 2010

SI-02233

15 20 25 30 35 40 45 50 55 60Sec.

21

23

25

21

23

25

15 20 25 30 35 40 45 50 55 60Sec

Figure 7. Refinery gas on the CP-Sil 5 CB column, channel 4

ConclusionThe 490 Micro GC QUAD was successfully used for the analysis of refinery gas. The permanent gases helium, hydrogen, oxygen, nitrogen, methane and carbon monoxide were analyzed on the Molsieve channel. The C2 hydrocarbons, carbon dioxide and hydrogen sulfide were analyzed on the second channel equipped with a CP-PoraPLOT U column. On the third channel, with an aluminium oxide column, the C3 and C4 hydrocarbons were analyzed. This channel was equipped with extra in-line filters to ensure moisture and carbon-dioxide-free carrier gas. This significantly enhanced column lifetime and ensured long-term stable retention times. Finally, the fourth channel, equipped with a CP-Sil 5 CB column, analyzed the C5+ hydrocarbons.

Mine Gas Analysis Using the 490 Micro GC

Application Note

IntroductionThis note describes the use of the 490 Micro GC for the analyses of mine gas, and especially carbon monoxide at low level, detection of which is essential for the safety of mine workers. Three independent GC channels analyze the sample in less than two minutes, including permanent gases and C1-C2 hydrocarbons.

AuthorsDarren BradySafety in Mines Testing and Research Station (SIMTARS)Department for Natural Resources and Mines, Queensland Government, Australia

2

Instrumentation490 Micro GC

• Channel 1: Molsieve

• Channel 2: Molsieve

• Channel 3: CP-PoraPlot Q

Materials and MethodsThe 490 Micro GC analysis uses argon on Molsieve channel 1. This was done to measure hydrogen, helium and all other permanent gases in one channel. Using argon as carrier gas gives an excellent response for hydrogen and helium but a reduced sensitivity for the permanent gases compared to using hydrogen/helium as carrier gas. The Limit of Quantification(LOQ)isapproximately50 to 100 ppm for oxygen, nitrogen andCO.Usingnitrogenascarriergasdetects no nitrogen, and almost no oxygen or carbon monoxide. Very low concentrations of oxygen and nitrogen (ppm level) can be measured on the carbon monoxide Molsieve channel 2.

Low carbon monoxide levels were detected on Molsieve channel 2, with no interference from bulk methane. ThemixturetotestlowlevelsofCOwas2ppmCOinmethane.TodetectlowCOinbulkmethanetwosettingsarecrucial.First,theuseofbackflushenables the elimination of peak tailing interference of the bulk methane duringtheelutionofCO.Secondly,the detector was set in the extra high sensitivity mode. However, as a result of using this mode, auto ranging of the detector was set off and high concentrations of components could not be measured, since the signal was cutoff.CO2,ethaneandethyleneweremeasured on channel 3 using a CP-PoraPLOTQcolumn.

70

20 100

Figure 1. Permanent gases on channel 1

20 100

43

2

1

Signal is cut off

Figure 2. Carbon monoxide on channel 2 70 12012070

4

5, approx 200 ppm

Figure 3. Low ppm carbon monoxide sample in methane, channel 2

70 120120

Methane bulk at >99%

Carbon monoxide at ppm level

Conditions

Table 1. Chromatographic conditions

Channel 1 Channel 2 Channel 310 m Molsieve 10 m Molsieve 10 m

CP-PoraPLOTQInjector Temp (°C) 50 50 50Column Temp (°C) 100 70 70Carrier Gas Argon Helium HeliumColumn Head Pressure, Static (kPa) 150 150 150Injection Time (ms) 100 100 100Back Flush Time (s) Not present 5.65 Not presentDetector Sensitivity Medium Extra high High

Results and DiscussionSeparationsareshowninthefigures,with Figure 1 indicating the effect of using the detector in extra high sensitivity mode. Figure 3 demonstrates the ability of the 490 Micro GC to detect trace levels of carbon monoxide in the presence of bulk methane.

Peakidentification Rt(s)

1. Hydrogen 27

2.Oxygen 37

3. Nitrogen 48

4. Methane 66

5. Carbon monoxide 111

6. Carbon dioxide 24

7. Ethylene 30

8. Ethane 34

20

20 40

Figure 4. Carbon dioxide, ethane and ethylene on channel 3

40

6

7 8

www.agilent.com/chemThis information is subject to change without notice.

© Agilent Technologies, Inc. 2010Published in UK, August 16, 2010

SI-02235

ConclusionThe 490 Micro GC successfully analyzed a sample of mine gas. The excellent performance of the instrument was shown by its capability to detect very low levels of potentially lethal carbon monoxide, even in the presence of bulk methane.

Fast On-Site Mine Safety Analysis bythe Agilent 490 Micro GC

Authors

Darren Brady

Safety in Mines Testing and Research

Station (SIMTARS)/Queensland

Government

Goodna, Australia

Remko van Loon



Application Note

Micro Gas Chromatography, Mine gas analysis, Mine safety

Abstract

Numerous mine disasters with loss of many lives continue to occur today. This fact

dramatically emphasizes the importance of fast and accurate determination of the

mine atmosphere for an early warning of hazards in day-to-day mine operations or

after an accident has happened. This application note describes a method for fast

on-site analysis of mine gases in less than 100 seconds using the Agilent 490 Micro

GC equipped with four independent column channels.

2

Introduction

We all can recall the news bulletins reporting a mine accidentand, in some cases, the many lives that are lost. Therefore, tohave an early warning for multiple safety reasons, fast analysis of the mine atmosphere is extremely important forday-to-day mining activities. Moreover, a complete overviewof the gases in the mine, after an accident, is essential todetermine if the mine is safe for a rescue team to enter.

First, it is necessary to check for explosive gases in a mineenvironment. During the formation of coal beds, some gases,mainly methane and some ethane and hydrogen were trappedin the coal. When these coal beds are mined, the gases arereleased. Methane and other explosive gases, when mixed incertain ratios with oxygen from the air, are highly explosive.To prevent explosion hazards, it is necessary to monitor flammable gases such as methane, hydrogen, and theC2 hydrocarbons.

A second reason for mine gas analysis is that the absence ofcarbon monoxide and the right oxygen and carbon dioxidelevels in the mine atmosphere are critical for the safety of themine workers and rescue teams.

Third, analyzing the gases in the mine can predict sponta-neous combustion or detect a fire in an early stage.Spontaneous combustion could happen when internal heat,produced by chemical reactions in the coal, is generatedfaster than it can be lost to the surrounding environment.Hydrogen and ethylene are formed when temperatures riseabove 100 °C. The presence of low concentrations of thesecomponents gives an indication of fire or elevated tempera-tures in an early stage. This increases the chance of successfully dealing with the problem.

The Safety in Mines Testing and Research Station (SIMTARS),based in Queensland Australia has been providing and supporting gas monitoring systems based on gas chromatographs to the mining industry for over 20 years andoffer their services, support, and training to mining companiesto reduce the risks of mine explosions and help them after amine disaster. For the three reasons given, SIMTARS is usingthe Agilent 490 Micro GC to provide a complete, fast, and on-site analysis of the gases collected from the undergroundmine.

Micro GC setup and conditionsThe 490 Micro GC (p/n G3581A) used for the analysis of minegas consists of a quad cabinet (Figure 1), and is equippedwith four column independent column channels. Each columnchannel is a complete, miniaturized GC with electronic carriergas control, micro-machined injector, narrow-bore analyticalcolumn, and micro-thermal conductivity detector (µTCD).

Figure 1. Agilent 490 Micro GC with quad channel cabinet housing.

3

The first channel installed, is equipped with a 10 meterCP-MolSieve 5Å column, running on argon as carrier gas forthe analysis of helium, hydrogen, oxygen, and nitrogen.Channels 2 and 3 are identical and, like the first channel, areequipped with a 10 meter CP-MolSieve 5Å column. However,these channels have the optional backflush functionality andrun on helium carrier gas, for the analysis of methane andcarbon monoxide. Ethane and ethylene are analyzed on afourth channel using a 10 meter a PoraPLOT U column.Table 1 shows the analytical conditions for all channels.

Agilent EZChrom Chromatography Data Software is used fordata acquisition, and SIMTARS EZGas Professional software,specifically written for the mining industry, is used for calibra-tion and result generating. The analysis results are exportedto Segas Professional, a software package developed by SIMTARS, for additional combustibility calculations, combustion ratios and trend analysis.

Fast mine safety analysis in less than 100 secondsThe first column channel, equipped with a CP-Molsieve 5Åcolumn, is used to analyze permanent gases, includinghelium, hydrogen, oxygen and nitrogen. Figure 2 shows achromatogram where the compounds of interest are well separated.

Figure 2. Chromatogram for helium, hydrogen, oxygen and nitrogen separation on the first columnchannel.

Table 1. Analytical Conditions for Quad Channel Micro GC

Channel 1 CP-Molsieve 5A 10 m



Channel 4 PoraPLOT U 10 m

Column temperature 80 °C 80 °C 80 °C 60 °C

Carrier gas argon, 120 kPa helium, 150 kPa helium, 150 kPa helium, 100 kPa

Injector temperature 50 °C 50 °C 50 °C 50 °C

Injection time 100 ms 110 ms 110 ms 90 ms

Back flush time no backflush 10 10 no backflush

Detector sensitivity auto auto auto auto

Invert signal yes no no no


Sampling time 70 seconds

0 20 40 60 80 100

Seconds

50 × zoom

Nitrogen

Oxygen

Helium 96 ppm

Hydrogen 194 ppm

Hydrogen 3.5 ppm

Helium 15 ppmSample 1Low ppm level helium and hydrogen

Sample 2 Medium ppm level helium and hydrogen

4

The molecular sieve channel is running on argon as the carrier gas, which enables the determination of low concen-trations of helium and hydrogen. All other compounds willhave an increased detection limit by approximately a factor of10, compared to helium, when argon is used as a carrier gas.However, oxygen and nitrogen are present at percentagelevels in the mine atmosphere, which allows the use of argoncarrier gas for detection of these gases. Concentration resultsfor hydrogen, oxygen, and nitrogen are used by SIMTARS forcombustibility calculations.

Helium, naturally available in our atmosphere at low ppm concentrations, is analyzed on this channel as well. On a molecular sieve column, helium and hydrogen elute closetogether. Analysis of helium prevents it from being incorrectlyreported as hydrogen. This can result in the erroneous conclusion that spontaneous combustion is occurring. Fromtime to time, helium is also used as a tracer gas to determinegas movements in the underground mine.

Channel two also includes a 10 meter MolSieve 5Å, this timewith helium as the carrier gas. This channel is used for theanalysis of methane and carbon monoxide. Figure 3 shows achromatogram for two different samples, one containing amedium level for carbon monoxide (~ 200 ppm) and the otherwith a very low level of carbon monoxide. In this chromato-gram, excellent separation and analysis of methane andcarbon monoxide in less than 100 seconds is obtained.

The typical limit of detection for the µTCD, specified byAgilent, is 1 ppm for early eluting components on a WallCoated Open Tubular (WCOT) column and 10 ppm on PorousLayer Open Tubular (PLOT) and micro-packed column types.The CP-MolSieve 5Å column is a PLOT type column, howeverwhen it comes to carbon monoxide at low levels, the exactconcentration is of less importance for SIMTARS than thetrend. Even a slight increasing trend of the chromatogram’sbase line at the carbon monoxide retention time is monitoredfor early indications of spontaneous combustion in the mine.

This MolSieve 5Å channel is equipped with back flush functionality to ensure moisture, carbon dioxide, and theC2 hydrocarbons are backflushed to vent, to maintain the separation efficiency of the molecular sieve column. Moistureand carbon dioxide tend to adsorb quickly to the Molsieve 5Åstationary phase changing its chromatographic properties.This could result, over time, in retention shifts and loss of separation.

For SIMTARS, the analysis of methane for explosion risk reasons and carbon monoxide for combustion identificationare of high importance, especially when the Micro GC is takeninto the field after a mine disaster. Therefore, this columnchannel is duplicated to the third position of the instrument toallow optimized operation for the analysis of each, and tohave a back up available at all times. When one column isreconditioned, the other column can still be used for analysis.

20 40 60 80 100

Seconds

Carbon monoxide 3 ppm

Carbon monoxide 193 ppm

Sample 1 Low ppm level carbon monoxide

Sample 2Medium ppm level carbon monoxide

Methane 120 ppm

Methane 0.79%

10 x zoom

Figure 3. Chromatogram for methane and carbon monoxide on the second column channel.

5

The fourth channel, equipped with a 10 meter PoraPLOT Ucolumn and helium as the carrier gas, is used to analyzecarbon dioxide, ethane, and ethylene. Figure 4 shows anexample for baseline separation of these three components.

The right carbon dioxide level is of importance for the safetyof the mine workers and rescue personnel. Moreover, theresults for carbon dioxide and ethane as well, are used in thecombustibility calculations by SIMTARS. Ethylene, like hydrogen, is formed when coal temperatures rise above100 °C and, therefore, is used as an early warning for spontaneous combustion or a fire.

Excellent repeatability for quantity and retentiontime Repeatability, reported as relative standard deviation, showsexcellent results for both concentration and retention time asshown in Table 2. Typical values, based on quantity, are deter-mined around 0.05% RSD for components that are present inthe sample at percentage levels and between 0.1 to 0.6% forppm level components. Retention time repeatability, for allcomponents of interest, is calculated at 0.015% or lower.

Figure 4. Chromatogram for carbon dioxide, ethane and ethylene on the fourth column channel.

30 40 50 60Seconds

Ethane 1.4 ppm

30 × zoom

Ethylene 1.9 ppm

Ethylene 113 ppm

Ethane 98 ppm

Carbon dioxide

Sample 1Low ppm levelethane andethylene

Sample 2Medium ppm levelethane andethylene

Table 2. Typical Repeatability Figures (Population Size is 10) for the Agilent 490 Micro GC

Column Concentration Concentration Concentration Retention time Retention timeComponent channel average unit RSD (%) average (seconds) RSD (%)

Helium 1 102.8 ppm 0.10 35.22 0.015

Hydrogen 1 118.5 ppm 0.11 38.79 0.014

Oxygen 1 20.4 % 0.044 54.65 0.0088

Nitrogen 1 72.4 % 0.056 70.00 0.011

Methane 2 (and 3) 1.85 % 0.054 54.09 0.0087

Carbon monoxide 2 (and 3) 181.9 ppm 0.25 71.35 0.012

Carbon dioxide 4 1.91 % 0.040 43.92 0.014

Ethylene 4 110.8 ppm 0.61 48.01 0.013

Ethane 4 92.3 ppm 0.25 51.62 0.013





Conclusion

This application note clearly show that the 490 Micro GC is apowerful tool for accurate mine safety analysis.

The major reason for SIMTARS using the 490 Micro GC isthat it provides a complete, fast and on-site analysis of themine gases collected from underground. Moreover, the 490Micro GC detects compounds that are not covered by themine’s continuous monitoring system.

The 490 Micro GC analyzes mine environment samples inless than 100 seconds resulting in multiple results per hourfor accurate trend analysis and thus better informed decisionmaking for the prevention of mine disasters.

In addition, the 490 Micro GC gives SIMTARS rapid and reli-able results to determine, after a mine disaster, the status ofthe underground environment before deciding to send in arescue teams.



Permanent Gases on a COX ModuleUsing a Agilent 490 Micro GC

AuthorsSimone Darphorn-Hooijschuur and

Marijn van Harmelen

Avantium

Amsterdam

The Netherlands

Remko van Loon and Coen Duvekot

Agilent Technologies

Middelburg

The Netherlands

Application Note

Micro Gas Chromatography

AbstractThis application note demonstrates the capabilities of the COX column with the

Agilent 490 Micro GC, including separation of permanent gases and backflush

possibilities to ensure extended column lifetimes.

IntroductionSeparation of permanent gases is usually performed on a Molsieve column. Thiscolumn offers the best separation for all permanent gases but also has some severedrawbacks. Water and carbon dioxide do not elute from a Molsieve column underregular GC conditions. A bake out at high temperatures (250 – 300 °C) is needed tofully regenerate the column. Regeneration is very time consuming in a Micro GCusually taking overnight or longer because the maximum temperature is 180 °C. In addition, it is likely that regeneration from moisture does not occur at this temperature.

If there is no need to separate oxygen and nitrogen, the COX column is a betteralternative. It delivers good separation of permanent gases, and carbon dioxideelutes from the column. COX is an ideal alternative for a Molsieve column, offeringprolonged lifetime and instrument uptime.

2

ExperimentalInstrumentationAn Agilent 490 Micro GC system with a COX column modulewas used for these experiments. The COX column modulewas equipped with a heated injector and an optinal precol-umn with backflush.

Conditions Column temperature 100 °C

Carrier gas Argon, 100 kPa

Backflush to vent time 13 s

Injection time 80 ms

Injection temperature 110 °C


Sampling time 30 s

Stabilization time 5 s

Run time 200 s

Sample Information Standard gas samples were used. Concentrations were in % levels.

40 60 80 100 120 140 160 180 200

Sec

1

2 3

4

5

6

Peak Identification1 He2 H

2

3 N2 + O

2

4 CO5 CH

4

6 CO2

0

Figure 1. Excellent baseline separation of a gas sample on a COX column.

Run He H2 N2 CO CH4 CO2

1 943213 16024030 20593423 1439534 1535598 1064007

2 947355 16092042 20685887 1444814 1538714 1062243

3 949818 16142635 20749728 1446996 1544418 1070193

4 949808 16167426 20781405 1449939 1542239 1066091

5 952725 16194789 20815739 1453498 1539162 1066940

6 952107 16206479 20826967 1456289 1543749 1063772

7 954648 16228802 20856620 1455219 1548126 1074325

8 954635 16249294 20879589 1456795 1547760 1079645

9 955454 16251565 20883920 1456611 1552320 1064839

10 955872 16250493 20901246 1473831 1547242 1065483

Average 951563.5 16180756 20797452 1453353 1543933 1067754

St. Dev 4053 75870 97930 9249 5122 5456

RSD% 0.43 0.47 0.47 0.64 0.33 0.51

Table 1. Repeatability Figures Per Component on Peak Area

Results and Discussion The above settings produce the chromatogram shown in Figure 1, with repeatability data in Table 1.

The chromatogram shows a baseline separation of helium andhydrogen. Oxygen and nitrogen eluted as a single peak butseparate from carbon monoxide and methane. Carbon dioxideeluted perfectly.

3

Other components such as water and higher hydrocarbonswere backflushed to vent.

If the backflush time is set at a high value then virtually allthe sample components enter the analytical column andeventually elute. However, if higher hydrocarbons are presentthe COX column is polluted because these components elutelate and can influence the succeeding analysis.

Figure 2 shows the elution of water and ethane if no back-flush is applied. If the backflush time is optimally tuned,water, ethane and higher hydrocarbons are backflushed tovent and does not enter the analytical column.

ConclusionFor the analysis of permanent gases the COX column is agood alternative to the commonly used Molsieve column.

Although the COX column does not separate oxygen andnitrogen, it does separate hydrogen and helium. In addition,carbon dioxide is analyzed and water elutes from the COXcolumn. Repeatability figures are good, ensuring reliableanalysis results.

The COX module can be equipped with a precolumn. Thisallows backflush of higher components and prolongs columnlifetime.

The Agilent 490 Micro GC is a rugged, compact and portable“lab-quality” gas analysis platform. When the composition ofgas mixtures is critical, this fifth generation Micro GasChromatograph generates more data in less time for fasterand better performance.

For More InformationFor more information on our products and services, visit ourWeb site at www.agilent.com/chem.

0 3Min

Optimal tuned backflush

Nitrogen

Methane

CO2

Water

Ethane

Water, ethane and higher hydrocarbonsare backflushed to vent.

Oven: 120 °CCarrier gas: helium, 200 kPa

No backflush

Figure 2. Backflush of water and ethane.



Information, descriptions, and specifications in this publication are subject to change without notice.

© Agilent Technologies, Inc., 2010Printed in the USADecember 28, 20105990-7054EN

Analysis of Acetone, n-Hexane, MIBK, MNBK, and MIBC Using the Agilent 490 Micro GC

Application Note

Authors

Tim Lenior and Hans-Peter Smid, ASaP

Amsterdam, the Netherlands

Remko van Loon



Introduction

This application note shows the analysis of Aceton, n-Hexane, Methyl iso-Butyl Ketone (MIBK), Methyl iso-Butyl Carbinol (MIBC), and Methyl n-Butyl Ketone (MNBK, 2-Hexanone) using the Agilent 490 Micro GC.

To decontaminate a polluted soil environment, steam is injected into the ground. The contaminants will evaporate from the soil and the steam is collected and cleaned. The 490 Micro GC is used to monitor this decontamination process.

The initial soil sample, including the contaminants, is collected and handled by a processing plant. This system, designed and build by Analytical Solutions and Products (ASaP) in the Netherlands, separates the gas from the soil sample. The fi nal gas sample, containing the contaminations in ppm range, high concentration of ambient air, and some moisture vapor, is analyzed by the 490 Micro GC. The compounds of interest can be separated on both a CP-Sil 5 CB column channel and a CP-Wax 52 CB column channel.

The Agilent 490 Micro GC is a rugged, compact and portable lab-quality gas analysis platform. When the composition of gas mixtures is critical, count on this fi fth-generation micro gas chromatography.

Micro Gas Chromatography, Environmental Analysis


Agilent shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.

Information, descriptions, and specifi cations in this publication are subject to change without notice.



These data represent typical results. For more information on our products and services, visit our Web site atwww.agilent.com/chem.

Instrumentation

For this analysis, an Agilent 490 Micro GC (p/n G3581A), equipped with a CP-Sil 5 CB and CP-Wax 52 CB, is used to analyze the compounds of interest.

CP-Wax 52 CB, 10m CP-Sil 5 CB, 4m (special)

Column temperature 60 °C 60 °C

Carrier gas Helium, 200 kPa Helium, 200 kPa

Injector temperature 60 °C 60 °C

Injection time 200 ms 200 ms

Sample line temperature 60 °C 60 °C

0 20 40Seconds

Water

Acetone

n-Hexane

CP-Sil 5 CBMethyl iso-Butyl Ketone (MIBK)

Methyl iso-Butyl Carbinol (MIBC)

Methyl n-Butyl Ketone (MNBK)

60 80 100 10 30 50Seconds

Water

Acetone

n-Hexane

CP-Wax 52 CB

Methyl iso-Butyl Ketone (MIBK)

Methyl iso-Butyl Carbinol (MIBC)

Methyl n-Butyl Ketone (MNBK)

70 90 110 130 150

Sample informationNitrogen/Oxygen (Air) Matrix

Acetone 64 ppm

n-Hexane 15 ppm

Methyl iso-Butyl Ketone (MIBK) 250 ppm

Methyl iso-Butyl Carbinol (MIBC) 73 ppm

Methyl n-Butyl Ketone (MNBK) 20 ppm

Analysis of BTEX in Air using the Agilent 490 Micro GC

Authors

Pascal Vattaire,


Les Ulis

France

Remko van Loon,


Middelburg

The Netherlands

Application Note


Introduction

Monocyclic aromatic hydrocarbons are a class of chemicals with a six membered ringstructure and alternating double and single bonds between the carbon atoms. Thesecompounds are considered to be toxic and therefore of interest for analysis.

This application note shows the analysis of benzene, toluene, ethylbenzene, and thexylenes in an air matrix using the Agilent 490 Micro GC. To separate all xylenes, includ-ing meta- and para-xylene, a special channel equipped with a 10-meter CP-Wax 52 CBcolumn is used. The standard 4-meter CP-Wax 52 CB column channel can be used forthe analysis of BTEX as well, however p- and m-xylene will co elute and reported as asingle result.

The advantage of the 490 Micro GC, in combination with the CP-WAX 52 CB columnchannel, is the ease-of-use and the speed of analysis. The analysis of the BTEX com-pounds is performed in less than 150 seconds. The Agilent 490 Micro GC delivers lab-quality separations in an ultra-compact, portable instrument. You get the results youneed in seconds - for faster, better decision making and confident process control.




© Agilent Technologies, Inc., 2011Printed in the USADecember 1, 20115990-9527EN

Instrumentation


Column channel CP-Wax 52 CB, 10 m (special channel)




Sample information

Matrix Air

Benzene low ppm range

Toluene low ppm range

Ethylbenzene low ppm range

Xylenes low ppm range



0 30 60 90 120 150

Sec

5x Zoom

Benzene

Toluene

Ethylbenzene

o-Xylene

m-Xylene

p-Xylene

5x Zoom

Analysis of Volatile Solvents on CP-Sil 5 CB using the Agilent 490 Micro GC

Application Note

Introduction

This application note shows the analysis of Ethyl acetate, n-Hexane, Cyclohexane, iso-Octane, Aniline, and Toluene in an Air matrix using the Agilent 490 Micro GC. Thesevolatile solvents, harmful to the environment, are analyzed on a CP-Sil 5 CB columnchannel in less than 2 minutes.

When you need to analyze on a location where no carrier gas or power is available,the portable field case option provides you measurements in the field. The 490 MicroGC can easily be transported in this fully self-contained field case, built-in gas cylinders, and rechargeable battery provide up to eight hours productive measuringtime.

The Agilent 490 Micro GC delivers lab-quality separations in an ultra-compact,portable instrument. You get the results you need in seconds, for faster, better decision making, and confident process control.

Micro Gas Chromatography, Environmental Analysis, Solvent Analysis

Author

Remko van Loon


Middelburg

The Netherlands

www.agilent.com/chemAgilent shall not be liable for errors contained herein or for incidental or consequentialdamages in connection with the furnishing, performance, or use of this material.


© Agilent Technologies, Inc., 2011Printed in the USAJuly 25, 20115990-8699EN

InstrumentationInstrument Agilent 490 Micro GC (G3581A) with portable

field case

Column channel 4 m CP-Sil 5 CB

Injector Unheated





For more information on our products and services, visit ourWeb site at www.agilent.com/chem.

0 30 60 90 120Seconds

n-Hexane

Ethyl acetate

Cyclohexane

iso-Octane

Aniline

Toluene

Air matrix

Analysis of Acetone, Methanol, andEthanol in Air using the Agilent 490 Micro GC

Authors

Mohamed Bajja and Remko van Loon,


Middelburg

The Netherlands

Application Note


Introduction

This application note shows the analysis of acetone, methanol, and ethanol in an airmatrix using the Agilent 490 Micro GC equipped with a CP-Wax 52 CB column channel.The advantage of the Agilent 490 Micro GC, in combination with the CP-Wax 52 CBcolumn channel, is the ease-of-use and the speed of analysis. The analysis is performed in less than 30 seconds.

The Agilent 490 Micro GC can optionally be equipped with a portable field case. This self-contained field case can be used to measure at a location where no carriergas or power is available. Build-in gas cylinders and rechargeable batteries provideup to eight hours productive field time.

The Agilent 490 Micro GC delivers lab-quality separations in an ultra-compact,portable instrument. You get the results you need in seconds – for faster, betterdecision making, and confident process control.




© Agilent Technologies, Inc., 2011Printed in the USAOctober 13, 20115990-9105EN

Instrumentation


Column channel CP-Wax 52 CB, 4 m





Sample information

Air Matrix

Acetone 0.07 %

Methanol 0.31 %

Ethanol 0.16 %



Composite air peak Methanol

Ethanol

Acetone

Seconds0 10 20 30

Analysis of Dichloromethane from Waste Water Using the 490 Micro GC

Application Note

AuthorsMartin PijlAgilent Technologies, Inc.

IntroductionDichloromethane (DCM) is a colorless, oily, organic liquid with a sweet, chloroform-like odor. It is mainly used to produce vinyl chloride monomer, the major precursor for PVC production. It is also used as a solvent for resins and fats, and in photography, photocopying, cosmetics, drugs and as a soil fumigant. DCM can be harmful to wildlife and human health, and so it is regulated in Europe under EC Directive 76/464 ‘Pollution of the aquatic environment by dangerous substances’ (plus daughter directives).

Fast, on-line analysis of DCM is accomplished using the Agilent 490 Micro GC.

2

InstrumentationInstrument: 490 Micro GC

Module: Fused silica, non- polar phase

Conditions Sample Conc: 7400 mg/m3 and 4 mg/m3Carrier Gas: Helium, ca. 45 kPaInjector Temp: UnheatedDetector: µ-TCD

Materials and Reagents Dichloromethane was extracted from waste water via purge and trap. The water was stripped and the stream directly analyzed via the 490 Micro GC.

Results and DiscussionFigures 1 and 2 show the effect of different dichloromethane concentrations on its separation.

20 [sec]

1

2

0 20Sec

1

2

Peak Identification1. Air2. Dichloromethane

5,000

10,000

15,000

20,000

25,000

Figure 1. Dichloromethane in air at 7400 mg/m3

Peak Identification1. Air2. Dichloromethane

www.agilent.com/chemThis information is subject to change without notice.© Agilent Technologies, Inc. 2010Published in UK, August 20, 2010SI-02642

20 [sec]

2

1

0 20Sec

-125

-100

-75

-50

-25

uV

1

2

Figure 2. Dichloromethane in air at 4 mg/m3

ConclusionThe 490 Micro GC successfully analyzed waste water samples containing dichloromethane, even at very low levels. The 490 Micro GC is a rugged, compact, “lab-quality” gas analysis platform that delivers high efficiency analyses. When the composition of gas mixtures is critical, this fifth generation micro-gas chromatograph generates more data in less time for faster and better performance.

Permanent Gas Analysis – Separation of Helium, Neon andHydrogen a MolSieve 5A column usingthe Agilent 490 Micro GC

Author

Remko van Loon


Middelburg

The Netherlands

Application Note

Micro Gas Chromatography, Permanent Gas Analysis

Introduction

This application note shows an example of the permanent gas analysis in a samplewith high % level of Oxygen and Nitrogen (Air) on an Agilent 490 Micro GC, includingthe separation of Helium, Neon, and Hydrogen (ppm level). The separation of thesecompounds is done on a 10 m MolSieve 5A column and requires the use of Argon ascarrier gas to detect all potential other carrier gases like Helium, Hydrogen, andNitrogen.

The advantage of the Agilent 490 Micro GC, is the ease-of-use and the speed ofanalysis, resulting in a total analysis time of less than 40 seconds.

The Agilent 490 Micro GC is a rugged, compact, and portable lab-quality gas analysisplatform. When the composition of gas mixtures is critical, count on this fifth generationmicro gas chromatography.






Column channel MolSieve 5A, 10 m


Carrier gas Argon, 240 kPa



Sample informationHelium ppm level

Neon ppm level

Hydrogen ppm level

Oxygen high % level

Nitrogen high % level



Permanent Gas Analysis – Separationof Argon and Oxygen on a MolSieve 5A Column using theAgilent 490 Micro GC

Application Note

Introduction

This application note shows an example of the analysis of permanent gases, includingthe separation of Argon and Oxygen, using the Agilent 490 Micro GC. For the separation of Argon and Oxygen, a High Resolution 20 m MolSieve 5A column is used.

The advantage of the Agilent 490 Micro GC is speed of analysis. Even with the 20 m HR MolSieve 5A column, you get the results fast. Total analysis time for the per-manent gases until Nitrogen is approximately 3 minutes. The Agilent 490 Micro GCdelivers lab-quality separations in an ultra-compact, portable instrument.


Authors

Mohamed Bajja and Remko van Loon


Middelburg

The Netherlands

www.agilent.com/chemAgilent shall not be liable for errors contained herein or for incidental or consequentialdamages in connection with the furnishing, performance, or use of this material.




Column channel 20 m MolSieve 5A





For more information on our products and services, visit ourWeb site at www.agilent.com/chem.

30 60 90 120 150 180

Seconds

Nitrogen

Argon

Hydrogen

Oxygen

Neon

Hydrogen

Neon

15 × Zoom

Sample informationNeon 18 ppm

Hydrogen 1.0 %

Argon 0.2 %

Oxygen 0.2 %

Nitrogen 0.2 %

Helium matrix

Fast Separation of Oxygen and Nitrogenon a MolSieve 5A Channel Using theAgilent 490 Micro GC

Authors

Mohamed Bajja and Remko van Loon


Middelburg

The Netherlands

Application Note


Introduction

When a really fast separation of Oxygen and Nitrogen is required, the Agilent 490 Micro GC, equipped with a short MolSieve 5A column channel, delivers thespeed you need.

This application note shows the fast separation of Oxygen and Nitrogen using a 4 m MolSieve 5A column channel instead of using the standard 10 m MolSieve 5Acolumn channel. The advantage of the Agilent 490 Micro GC, in combination withthis 4 m MolSieve 5A column channel, is the ease-of-use and the speed of analysis.Nitrogen will elute in less than 20 s.

Argon and Oxygen will not be separated on the 4 m MolSieve 5A column. Thesecompounds will coelute. The separation of Argon and Oxygen requires the use of a20 m MolSieve 5A column channel on a low temperature.

The Agilent 490 Micro GC is a rugged, compact and portable lab-quality gas analysis platform. When the composition of gas mixtures is critical, count on thisfifth generation micro gas chromatography.






Column channel MolSieve 5A, 4 m




Sample informationHydrogen 1.0%

Oxygen 0.4%

Nitrogen 0.2%



C1 – C3 Hydrocarbon Analysis Using the Agilent 490 Micro GC – SeparationCharacteristics for PoraPLOT U andPoraPLOT Q Column Channels

Author

Remko van Loon


Middelburg

The Netherlands

Application Note

Micro Gas Chromatography, Hydrocarbon analysis

Introduction

This application note shows the possibilities and limitations in fast analysis of saturated and unsaturated C1 to C3 hydrocarbons using an Agilent 490 Micro GC.The chromatograms and results outline the similarities and differences when usinga CP-PoraPLOT U and a CP-PoraPLOT Q columns channels. Both the PoraPLOT Uand the PoraPLOT Q are capable of resolving methane from the composite air peakand separate CO2 from methane and the C2 hydrocarbons.

The PoraPLOT U column channel will have the following separation characteristics:

• Baseline separation for ethane, ethylene and acetylene• Coelution of propane and propylene

The separation characteristics for the PoraPLOT Q column channel are:

• Coelution of ethylene and acetylene• Baseline separation for propane and propylene




© Agilent Technologies, Inc., 2011Printed in the USAOctober 4, 20115990-9165EN

If you want to the ability to measure anywhere and get theresults you need in seconds, the Agilent 490 Micro GC is theideal solution. With its rugged, compact, laboratory qualitygas analysis platform, the 490 Micro GC generates more datain less time for faster, and better, business decisions.

Instrumentation

For this application an Agilent 490 Micro GC (G3581A)equipped with a PoraPLOT U and a PoraPLOT Q was used.The setup parameters for the column is found in the tablebelow.


These data represent typical results. For more informationon our products and services, visit our Web site atwww.agilent.com/chem.

PoraPLOT U, 10 m PoraPLOT Q, 10 m

Column temperature 80 °C 80 °C

Carrier gas Helium, 200 kpa Helium, 200 kpa

Injector temperature 110 °C 110 °C

Injection time 20 ms 20 ms

0 20 40 60 80 100Seconds

PoraPLOT UComposite air peak

MethaneCarbon dioxide

Ethylene

Ethane

Acetylene

5 × zoom

PropadienePropyne

Propane/propylene

0 20 40 60 80Seconds

PoraPLOT Q Composite air peak

Methane

Carbon dioxideEthylene/acetylene

Ethane

5 × zoom

Propadiene

Propyne

Propane

Propylene

Sample information

Nitrogen Balance

Methane 5.0 %

Carbon dioxide 3.0 %

Etylene 2.0 %

Ethane 4.0 %

Acetylene 1.0 %

Propylene 1.0 %

Propane 2.0 %

1,2-Propadiene 0.97 %

Propyne 0.99 %

The following is a list of gases that we have prently analyzed with the Varian Chrompack MicroGC.

We will continue to add gases as we develop new application directly or via our customer.

For all new compound not present in this list contact you nearest Varian office.

MicroGC Column modules choice list for applications (Max. two per system).

Molsieve 5A : permanent gases, methane, CO, NO ,etc.(H.R. for O2-Ar baseline separation)

Hayesep A : hydrocarbons C1-C3, N2, CO2, air, volatile solvents ,etc.

CP-sil 5,8 CB : hydrocarbons C3-C10, aromatics, organic solvents, etc.

CP-sil 19 CB : hydrocarbons C4-C10, high boiling solvents, BTX, etc.

CP-WAX 52 CB : polar higher boiling solvents, etc.

PLOT Al2O3/KCl : light hydrocarbons C1-C5 saturated and un-saturated , etc.

Poraplot Q,U : hydrocarbons C1-C6, freons, Anaestetics,H2S, CO2, SO2, volatile solvents,..

CP-COX : CO, CO2, H2, air, CH4, etc.

CP SIL 19 Special : THT and C3-C6 + in Natural Gas Matrix, etc.

CP SIL 13 Special : TBM and C3-C6+ in Natural Gas Matrix, etc.

CP Poraplot Special : PPQ, specially tested for H2S in natural gas (10 to 50 ppm)

CP Sulphur Special : Unique column specially tested for MES (Spotleak 2323) in natural gas (1 ppm)

Varian Chrompack MicroGC Column module choice list for single compound.The limit of quantification L.O.Q. (two times the noise) is just as reference level, matrix, carrier gas and other parameters should influence the sensitivity.The (x) indicates witch column(s) will do the separation..

COMPOUND Molsieve Haysep CPCOX CPSil 5 8/13/1CPWax CPAl2O3 Poraplot

L.O.Q. 10ppm 10 ppm 10 ppm 1 ppm 1 ppm 1 ppm 1 ppm

ABLUTON T30 X

ACETENE X

ACETIC ACID BUTYL ESTER X

ACETIC ACID ETHYL ESTER X

ACETIC ETHER X

ACETIDIN X

ACETONE X

ACETONE, METHYL X

ACETOXYTHANE X

ACETYLEN X

ACETYLENE X

ACETYLENE

DICHLORIDE X

ACETYLENE

TRICHLORIDE X

ACRALDEHYDE X

ACROLEIN X

ACRYLALDHYDE X

ACRYLIC ALDEHYDE X

AEROTHENE X

AEROTHENE MM X

AEROTHENE TT X

AETHER X

AETHYLIS X

AETHYLIS CHLORIDUM X

MICRO GC APPLICATION TABLE

ros

Temp Errata

AIR X X

ALCOHOL X

ALCOHOL DENATURED X

ALCOHOL

METHANOL X

ALCOHOL PROPYL ISO REGAL X

ALCOHOL DEHYDRATED X

ALCOHOL DENATURATED X

ALCOHOL ISOPROPYL X

ALCOHOL METHYL X

ALCOHOLS X

ALCOWIPE X

ALGOFRENE TYPE2 X

ALGOFRENE

TYPE6 X

ALGRAIN

ALLENE X

ALLYLENE X

ALTENE DG X

ANESTHESIA ETHER X

ANESTHESIC

ETHER X

ANHYDROL X X

ANKILOSTIN X

ANODYNON X X

ANTISOL 1 X

ANYDROUS DIETHYL ETHER X

AQUALIN X

AQUALINE X

ARCTON 4 X X

ARCTON 6 X

ARCTON O X X

ARGON X

ARKLONE X

AVANTINE X

BALTANE CF X

BALTANE D X

BENZENE X

BENZENE METHYL X

BENZENE PROPYL X

BENZENE CHLORO X

BENZENE ETHYL X

BENZENE CHLORIDE X

BENZOLENE X

BFV X

BICARBURRETED HYDROGEN X X X

BICHLOETHANE 1,2- X X

BIETHYLENE X

BIMETHYL X X X

BIOCIDE X

BIOGAS X X X X

BIVINYL X

BLAZER BUTANE FUEL X X

BLAZER BUTANE GAS X X

BORER SOL X X

BROCIDE X X

BU-GAS X X

BUTA-1,3-DIENE X

BUTADIENE X

BUTADIENE 1,3 X

BUTANE X X

BUTANE N- X X

BUTANE FUEL X

BUTANE.2-METHYL X

BUTANOL X

BUTANOL 1- X

BUTANOL N- X

BUTANONE 2- X

BUTANONE

(MEK) 2 X

BUTANONE , 2- X

BUTENE 1- X

BUTENE CIS-2 X

BUTENE TRANS-2- X

BUTENE (E)-2- X

BUTENE (Z)-2- X

BUTENE -(E)-2- X

BUTENE , (E)-2- X

BUTENE ,(Z)-2- X

BUTENE-CIS -2 X

BUTYL ACETATE X

BUTYL ACETATE 1- X

BUTYL ACETATE N- X

BUTYL ALCOHOL 1- X

BUTYL ALCOHOL N- X

BUTYL ALCOHOL X

BUTYL ALCOHOL ACETATE X

BUTYL ALCOHOL, ACETATE X

BUTYHL ETHANOATE X

BUTYLENE A- X

BUTYLENE R- X

C10 N- X

CARBINOL X

CARBON BICHLORIDE X

CARBON CHLORIDE X

CARBON DIOXID X X

CARBON DIOXIDE X X

CARBON DIOXIDE

CALIBRATION SALT X X

CARBON DIOXIDE FILLING SOLUTION X X

CARBON FLUORIDE X X

CARBON MONOXIDE GAS X

CARBON MONOXIDE IN AIR X

CARBON OXIDE (CO) X

CARBON TETRACHLORIDE X

CARBON TETRAFLUORIDE X

CARBONA X

CARBONIC ACID GAS X X X

CARBONIC ANHYDRIDE X X X

CARBON OXIDE X X

CARBONICE X X X

CARDICE X X X

CATION HYDROGEN FORM X X

CFC 10 X

CFC 11 X

CFC 113 X

CFC 123 X

CFC 134A X

CFC 14 X

CFC 20 X

CFC 22 X

CFC 30 X

CFC -11 X

CFC 12 X

CH4 X X X X

CH4 IN N2 X X X X

CHELEN X

CHEVRON ACETONE X

CHLORBENZEN X

CHLORDIFUORO-METHANE X

CHLORDIFUORO-METHANE AIR DUST REMOVER X

CHLORDIFUORO-METHANE DUST REMOVER X

CHLORDIFUORO-METHANE IN AIR DUST REMOVER X

CHLORETHYL X

CHLORFORM X

CHLORIDUM X X

CHLORINATED FLUOROCARBON X

CHLOROBENZENE X

CHLOROBENZOL X

CHLORODIFLUO-ROMETHANCE X

CHLORODIFLUO-ROMETHANE X

CHLOROETHANE X X

CHLOROETHENE X

CHLOROETHYLE-NE X

CHLOROFLUORO-CARBON X

CHLOROFORM

METHYL X

CHLOROFORM X

CHLOROTHANE NU X

CHLOROTHENE X

CHLOROTHENE VG X

CHLORTEN X

CHLORYL X X

CHLORYL

ANESTHETIC X X

CIS-2-BUTYLENE X

CLEAN D M- X

CO2 X X X

COLOGNE SPIRIT X

COLONIAL SPIRIT X

COLUMBIAN SPIRIT X

CYCLOHEXATRIENE X X

DABCO CS90 X

DCM X

DECANE X

DECANE N- X

DELF FABRIC PROTECTOR X

DENATURED ALCOHOL X

DENATURE ETHYL ALCOHOL X

DENATURED SPIRIT X

DESTRUXOL BORER-SOL X

DICARBURRETED HYDROGEN X

DICHLOREMUL-SION X

DICHLORETANE

1,2- X X

DICHLORETHYLENE 1,2- X

DI-CHLOR-MULSION X

DICHLOROMETHANE X

DICHLORO-1,1,1-

TRIFLUOROETHANE 2,2- X

DICHLORODIFLUORO METHANE X

DICHLORODIFLUOROMETHANE X

DICHLOROETHA-NE 1,2- X

DICHLOROETHA -NE 1,3- X

DICHLOROETHA-NE (ETHYLENE CHLORIDE) 1,2- X

DICHLOROETHA-NE (PHOTREX) 1,2- X

DICHLOROETHA-NE D4 1,2- X

DICHLOROETHE-NE 1,2- X

DICHLOROETHE-NE S (TOTAL), 1,2- X

DICHLOROETHY-LENE 1,2- X

DICHLOROETHY-LENES 1,2- X

DICHLOROMETHANE X

DICHLOROMETHANE (METHYLENE CHLORIDE) X

DICHLOROTRI-FLUOROETHANE X

DIDAKENE X

DIETHYL X X X

DIETHYL ETHER X X

DIETHYL OXIDE X

DIFF-QUICK FIXATIVE X

DIFLON S-3 X

DIFLUOROCHLO-ROMETHANE X

DIFLUORODICHLOMONOMETHANE X

DIHYDROGEN

OXIDE X

DIMETHYL X X X

DIMETHYL KETONE X

DIMETHYLBENZENE 1,2- X



DIMETHYLCARBINOL X

DIMETHYLETHY-LENE 1,1 X

DINITROGEN OXIDE X

DIOFORM X

DIPROPAL METHANE X

DIPROPYL METHANE X

DISPARIT B X

DISTILLEX DS1 X

DISTILLEX DS2 X

DISTILLEX DS4 X

DISTILLEX DS5 X

DISTILLEX DS6 X

DIVINYL X

DRICOLD X X X

DRIKOLD X X X

DRIVERIT X

DRY ICE X X X

DRY ICE6 X X X

DUTCH LIQUID X

E 290 X X X

E 938 X

E 939 X

E 941 X

E 942 X

EB X

EDC X

ELAYL X X

ELECTRO-CF 12 X

ELECTRO-CF 22 X

ERYTHRENE X

ESKIMON 12 X

ESKIMON 22 X

ETHANA X

ETHANE X X X

ETHANE 1,1,1,-

TRICHLORO- X

ETHANE 1,1,2,-

TRICHLORO-1,2,2-TRIFLUORO- X

ETHANE 1,1’-OXYBIS X

ETHANE, 1,2-DICHLORIDE X

ETHANE ,1,1,2,-

TRICHLORO-1,2,2-TRIFLUORO- X

ETHANE ,1,1’-OXYBIS X

ETHANE ,1,2,-

DICHLORO- X

ETHANE ,2,2,-

DICHLORO-1,1,1-TRIFLUORO- X

ETHANE, CHLORO- X

ETHANE, PHENYL- X

ETHANOL X

ETHENE CHLORO- X

ETHENE TETRA-CHLORO- X

ETHENE TETRACHLORO- X

ETHENE X X

ETHENE, TRICHLORO X

ETHER X

ETHER CHLORATUS X X

ETHER HYDROCHLORIC X X

ETHER MURIATIC X X

ETHER, ETHYL X X

ETHINE X X X

ETHOL ALCOHOL X X

ETHOXYETHANE X X

ETHY ETHER X X

ETHYL ACETATE X

ETHYL ACETIC ESTER X

ETHYL ALCHOHOL X X

ETHYL ALCOHOL X X

ETHYL CHLORIDE X X

ETHYL CHLORIDE BP X X

ETHYL ETHANOATE X X

ETHYL ETHER X X

ETHYL ETHER A.C.S. X X

ETHYL HYDRATE X X X

ETHYL HYDRITE X X X

ETHYL HYDROXIDE X X X

ETHYL METHYL

KETONE X

ETHYL OXIDE X

ETHYLACETATE X

ETHYLALACOHOL ZOO PROOF X

ETHYLBENZENE X

ETHYLBENZOL X

ETHYLCHLORIDE X X

ETHYLCYCLOEXAN

ETHYLDIMETHYL-METHANE X X

ETHYLENE X X X

ETHYLENE TETRACHLORO- X

ETHYLENE TRICHLORO- X

ETHYLENE CHLORIDE X

ETHYLENE DICHLORIDE 1,2- X

ETHYLENE DICHLORIDE X

ETHYLENE MONOCHLORIDE X

ETHYLENE TRICHLORIDE X

ETHYLETHYLENE X

ETHYLIDENE DICHLORIDE 1,2- X

ETHYLOL X

ETHYNE X X X

ETOH X X

EVERCLEAR X X

EXHAUST GAS X X

EXXSOL HEPTANE X X

EXXSOL HEXANE X

EXXSOL ISOPENTANE X

F12 X

F14 X

F22 X

FA X

FANNOFORM X

FASCIOLIN X

FC12 X

FC14 X

FEDAL-UN X

FERMANTATION X X

ALCOHOL X X

FIRE DAMP X X X X X

FLUE GAS X X

FLUKOIDS X

FLUOROCARBON 11 X

FLUOROCARBON 12 X

FLUOROCARBON 22 X

FLUOROCARBON -12 X

FLUOROCARBON-22 X

FLUOROTRICHLOROMETHANE X

FORMALDEHYDE X

FORMALDEHYDE

GERMACIDE X

FORMALIN X

FORMALIN 40 X

FORMALITH X

FORMIC ALDEHYDE X

FORMOL X

FORMYL TRICHLORIDE X

FREON X

FREON 11 X

FREON 12 X

FREON 14 X

FREON 20 X

FREON 22 X

FREON 30 X

FREON F-12 X

FREON MF X

FREON R-11 X

FREON R-12 X

FREON R-22 X

FREON TF X

FRIGEN X

FRIGEN 12 X

FURAR TETRAHYDRO- X

FYDE X

GENESOLV A SOLVENT X

GENESOLV D SOLVENT X

GENETRON 11 X

GENETRON 12 X

GENETRON 22 X

GLYCOL DICHLORIDE X X

GRAIN ALCOHOL X X

H20 X X X

HALOCARBON 22 X

HALON 14 X

HCFC 22 X

HELIUM X

HELIUM, HP X

HEPTANE X

HEPTANE N- X

HEPTANE, N- X

HEPTYL HYDRIDE X

HERCULES 37M6-8 X

HEXAN X

HEXANE X

HEXANE N- X

HEXONE X

HEXYL HYDRIDE X

HFC 22 X

HIGH PRURITY METHANOL X

HOCH X

HYDROCARBONS C6 X

HYDROCARBONS C7 X

HYDROCARBONS C8 X

HYDROCARBONS C9 X

HYDROCHLORIC ETHER X X

HYDROGEN X X

HYDROGEN (H2) X X

HYDROGEN MIN. X X

HYDROGEN OXIDE X

INHIBISOL X

IPA X

ISANOL X

ISCEON 22 X

ISOBUTANE X X X

ISO-BUTANE X X X

ISOBUTENE X X X

ISO-BUTENE X X X

ISOBUTYLENE X X X

ISO-BUTYLENE X X X

ISOCOUMENE X

ISOPENTANE X

ISOPROPANOL X

ISOPROPYL ALCOHOL X

ISOPROPYLACETONE X

ISOTRON 12 X

ISOTRON 22 X

IVALON X

JAYSOL S X X X

KARSAN X

KATHARIN X

KELENE X X

KETONE PROPANE X

KETONE, DIMETHYL X

KETONE, METHYL ETHYL X

KETOPROPANE B- X

LAUGHING GAS X X

LEDON X

LUTOSOL X

LYSOFORM X

MARSH GAS X X X X

MASTER APPLIANCE BUTANE FUEL X X X

MCB X

MEETCO X

MEK X

MEOH X X

MES XSPEC

METHANAL X

METHANE X X X X X

METHANE TETRACHLORO- X

METHANE TRICHLORO- X

METHANE DICHLORIDE X

METHANE, CHLORODIFLUO

RO- X

METHANE,

DICHLORO- X

METHANE,

DICHLORODI

FLUORO X

METHANE TETRAFLUORO- X

METHANE,

TRICHLOROFLUORO X

METHANOL X X

METHOKLONE X

METHYALCOHOL X X

METHYL ACETONE X

METHYL ALCOHOL X X

METHYL ALCOHOL

(ANHYDROUS) X X

METHYL ALCOHOL

(METHANOL) X X

METHYL ALDEHYDE X

METHYL ETHYL KETONE X

METHYL HYDRATE X X

METHYL HYDRIDE X X X X X

METHYL HYDROXIDE X X

METHYL ISOBUTYL KETONE X

METHYL KETONE X

METHYL PROPENE X

METHYL-1-PROPENE 2- X

METHYL-2-PENTANONE 4- X

METHYL-2-PENTANONE, 4- X

METHYL-2-PROPANETHIOL 2- X

METHYLACETYLENE X

METHYLALCO HOL X X

METHYLBENZENE X

METHYLBUTANE 2- X

METHYLCARBI NOL X X

METHYLCHLORO

FORM X

METHYLCYCLOEXANE

METHYLENE BICHLORIDE X

METHYLENE CHLORIDE X

METHYLENE DICHLORIDE X

METHYLENE GLYCOL X

METHYLENE OXIDE X

METHYLETHENE X

METHYLETHYLE NE X

METHYLETHYL METHANE X X

METHYLFORMATE X

METHYLMETHA NE X X X

METHYLOL X X

METHYLPROPANE 2- X

METHYLPROPANE (ISOBUTANE) 2- X

METHYLPROPANE ,99% (ISOBUTANE) 2- X

METHYLPROPENE 2- X

MIBK X

MOLASSES ALCOHOL X X

MOLECULAR HYDROGEN X X

MONOCHLORE THANE X X

MONOCHLOR

BENZENE X

MONOCHLORE

THANE X X

MONOCHLORO

BENZENE X

MONOCHLORODI

FLUOROMETHA

NE X

MONOCHLORO

ETHANE X X

MONOCHLORO

ETHENE X

MONOFLUORO

TRICHLORO

METHANE X

MONOHYDROXYMETHANE X X

MORBICID X

MURIATIC ETHER X X

M-XYLENE X X

N2 X X X

N20 X

NARCOTILE X X

NARCYLEN X

NARKOTIL X X

NECATORINA X

NEMA X

NEON X

NEVOLIN X X X

NITRAL X X

NITROGEN X

NITROUS OXIDE X X

NONANE X

NONAE N- X

NORFLURANE X X

NORMAL HEPTANE X

NORMAL HEXANE X

O2 X

OXOMETHANE X

OXYBISETHANE X

OXYGEN X

O-XYLENE X

OXYMETHYLENE X

PENTANE X

PENTANONE, 4-METHYL- 2- X

PER X

PERAWIN X

PERCHLOR X

PERCHLOROETHY

LENE X

PERCHLOMETHA

NE X

PERCLENE X

PERCOSOLVE X

PERFLUOROME

THANE X

PERK X

PERKLONE X

PERSEC X

PETRHOL X

PHENE X

PHENYL CHLORIDE X

PHENYL HYDRIDE X

PHENYLCHLORI DE X

PHENYLETHANE X

PHENYLMETHANE X

POLYOXYMETHY

LENE GLYCOLS X

POLYRINYL ALCOHOL X X

POTATO ALCOHOL X X

PROP-2-EN-1-AL X

PROPADIENE X

PROPADIENE 1,2- X

PROPANE X X X X

PROPANE, 2-METHYL- 2-

PROPANOL 2-

PROPANONE 2-

PROPANONE

PROPELLANT 12 X

PROPELLANT 22 X

PROPEN-1-ONE 2- X

PROPENAL 2- X

PROPENAL X

PROPENE X X

PROPENE, 2-METHYL-1- X X

PROPENE,2,

METHYL- X X

PROPYL CARBINOL X

PROPYLBENZENE X

PROPYL

CARBINOL X

PROPYLENE X X

PROPYNE X

PUNCTILIOUS ETHYL ALCOHOL X

PURE ETHYL ALCOHOL X X

P-XYLENE X X

PYRO X X

PYROACETIC ETHER X X

PYROBENZOL X X

PYROXYLIC SPIRIT X X

PYRROLYENE X

PYRROLYLENE X

R 10 X

R14 X

R30 X

R-22 X

REAGENT ALCOHOL X X

REFRIGERANT 11 X

REFRIGERANT 12 X

REFRIGERANT 12

DICHLORODIFLUO

TOMETHANE X

REFRIGERANT 22 X

REFRIGERANT 30 X

REGEATTE X X

RONSON BUTANE FUEL X X X

RONSON MULTI-FILL BUTANE FUEL X X X

SASETONE X

SHELL ACETONE X X

SLIMICIDE X

SOLAESTHIN X

SOLMETHINE X

SOLVETHANE X

SPIRIT X X

SPIRIT OF WINE X X

STERETHOX X

STYRENE

SULFURIC ETHER X

SUPERLYSOFORM X

SYM-DICHLOROETHY

LENE X

SYNASOL X

SYN-DICHLORO

ETHANE X

SYS -DICHLOROETHY

LENE X

TCE X

TCM X X

TEBOL 88 X X

TEBOL 99 X X

TECSOL

TERT-BUTANETHIOL X

TERT-BUTYL MERCAPTAN X

TESCOL X

TETLEN X

TETRACAP X

TETRACHLORE

THYLENE X

TETRACHLORO

ETHENE X

TETRACHLORO

ETHYLENE X

TETRACHLOME

THANE X

TETRAFINOL X

TETRAFLUORO

ETHANE 1,1,1,2- X

TETRAFLUORO

ETHANE X

TETRAFORM X

TETRAHYDRO

FURAN X

TETRAHYDRO

THIOPHENE

TETRALENO X

TETRALEX X

TETRAOXY

METHYLENE X

TETRASOL X

TETRAVEC X

TETROGUER X

TETROPIL X

THAWPIT X

THF X

THIOPHENE

TETRAHYDRO-

TOGA X X

TISSUE FIXATIVE X

TOLUENE X

TRIAZINEN,N’,N”-TRICHLORO-2,4,6,-TRIAMINO -1,3,5- X

TRICHLORO-1,2,2-

TRIFLUOROETHANE X

TRICHLORO-1,2,2-

TRIFLUOROETHANE 1,1,2- X

TRICHLORO ETHANE 1,1,1- X

TRICHLORO ETHANE X

TRICHLORO ETHENE X

TRICHLORO ETHYLENE X

TRICHLORO ETHYLENE 1,1,2- X

TRICHLORO ETHYLENE , 1,1,2- X

TRICHLORO ETHYLENE -14C X

TRICHLORO ETHYLYENE X

TRICHLORO

FLUORO METHANE X

TRICHLORO

FLUOROMETHANE X

TRICHLOROFORM X

TRICHLORO

METHANE X

TRICHLOROME THANE 1,1,1,- X

TRICHLOROMONO

FLUOROMETHANE X

TRICHLOROSTHONE 1,1,1- X

TRICHLOROTRI

FLUOROETHANE

1,1,2- X

TRICHLOROTRI

FLUOROETHANE

1,2,2- X

TRICHLOROTRI

FLUOROETHANE X

TRICLENE X

TRI-ETHANE X

TRIFLUORO-1,2,2,

TRICHLOROETHA

NE 1,1,2- X

TRIFLUORO-

TRICHLOROETHA

NE 1,1,2- X

TRIKLONE X

TRILENE X

TRIMETHYLME

THANE X

UCON 12 X

UCON 22 X

UHP HELIUM X

UHP METHANE X X X X X

ULTRATANE BUTANE FUEL X X

UNIVERM X

UNS.DIMETHYL

ETHYLENE X X

USI IN OVAL X

VC X

VCM X

VERMOESTRICID X

VINEGAR NAPHTHA X

VINYL CHLORIDE X

VINYL CHLORIDE

MONOMER X

VINYLETHYLENE X

WATER X

WESTROSOL X

WOOD ALCOHOL X

WOOD NAPHTHA X

WOOD SPIRIT X

XENON X

XYLENE 1,2- X X

XYLENE 1,3- X X

XYLENE 1,4- X X

XYLENE M- X X

XYLENE O- X X

XYLENE P- X X

XYLENE-D10 O- X X

XYLENE -D10 P- X X

Hv

micro process gas chromatograph ( pgc) analyses … solutions and products bv micro process gas...

Documents