Solutions for Light

Hydrocarbons and

Gases: PLOT Columns

Phil Stremple Ph.D.

Agilent Technologies

Wilmington, DE USA

July 31, 2014 1

July 31, 2014

Carbon # C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 Bpt of n-Paraffin

@ 760 mm Hg

Centigrade -161 -89 -42 -0.5 +36 69 98 126 151 174 196 216 235 253 270 287

Fahrenheit -259 -127 -44 +31 97 156 209 258 303 345 384 421 421 488 519 548

Refinery off gas

Naphtha solvents

Cracking naphtha

Reformate

Gasoline

Kerosene, Diesel

Jet fuel

Gas oil

Lube oil

Pitch asphalt

Wax

Residues

to C18

to C17

to >C20

C20

C20

C44+

C17

Table of Boiling Point Fractions

2

July 31, 2014

Gas

Flow

Fused Silica

Tubing

Stationary phase

Stationary phase

Kc => Large Kc => Small

Wall Coated Open Tubular (WCOT) Columns

3

Midrange Hydrocarbon Separation

July 31, 2014

Column: DB-DHA

100 m x 0.25 mm id, 1.0 µm DB-1

5 meters of DB-5, 0.25 mm id, 1.0 µm

Carrier: Helium at 24 cm/sec (measured at 35 °C)

Oven: 5 °C for 10 min

5-50 °C at 5 °C/min

50 °C for 52 min

50 – 200 °C at 1.4°/min

Injector: Split 1:100. 250 °C, 0.3 µL unleaded gasoline

Detector: FID, 250 °C

Nitrogen makeup gas at 30 mL/min

4

July 31, 2014

High Temp Sim Dist Analysis

n-Paraffins

Column: DB-HT Sim Dist

5 m x 0.53 mm id, 0.15 µm

Carrier: Helium at 18 mL/min, measured at 35 °C

Oven: - 30 – 430 °C at 10°/min

Injector: OPTIC PTV

55 – 450 °C at 2 °/sec

0.5 µL of about 2% n-Paraffins in CS2

Detector: FID, 450 °C

Nitrogen makeup gas at 15 mL/min

n-Paraffin standard showing distillation range from C6 to C110 on DB-HT Sim Dist

Time(minutes) 0 5 10 15 20 25 30 35 40 45

24

50

6

7

8

9

10

16

11 12

70

50

40

90 80

60

14

18

20 28 30

32

110

5

July 31, 2014

Carbon # C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 Bpt of n-Paraffin

@ 760 mm Hg

Centigrade -161 -89 -42 -0.5 +36 69 98 126 151 174 196 216 235 253 270 287

Fahrenheit -259 -127 -44 +31 97 156 209 258 303 345 384 421 421 488 519 548

Refinery off gas

Naphtha solvents

Cracking Naphtha

Reformate

Gasoline

Kerosine, Diesel

Jet Fuel

Gas Oil

Lube Oil

Pitch Asphalt

Wax

Residues

to C18

to C17

to >C20

C20

C20

C44+

C17

Table of Boiling Point Fractions

6

Column: DB-Petro 100

100 m x 0.25 mm id , 0.5 µm

Carrier: Helium at 28.5 cm/s

Oven: - 40 °C for 20 min

- 40 °C – 120 °C at 5 °C/min

Injector: Split 1:16, 100 µL, 200 °C

Detector: FID, 250 °C

July 31, 2014

Ethylene

7

Ethylene

1. Methane

2. Ethylene

3. Ethane

4. Propylene

July 31, 2014

Column: DB-Petro 100

100 m x 0.25 mm id, 0.5 µm

Carrier: Helium at 28.5 cm/s

Oven: - 40 °C for 20 min

- 40– 120 °C at 5 °C/min

Injector: Split 1:16, 100 µL, 200 °C

Detector: FID, 250 °C

Propylene

8

Propylene

1. Methane

2. Ethylene

3. Propylene

4. Propane

July 31, 2014 9

Source: Wikipedia

July 31, 2014 10

Liquid coating

WCOT Adsorbent coating

PLOT

Capillary columns

Solvents

Semivolatiles

Pesticides

High boiling

Gases

Volatiles

Siloxanes liquid phases

Wax liquid phases

Alumina

Porous carbon

DVB Porous polymer

Agilent J&W GC Column Portfolio

What is a PLOT Column?

• Porous layer on the inner wall of the capillary

• Porosity achieved by the deposition of porous particles on

the wall from a suspension

• Porous layer serves as stationary phase

• Separation mechanism (Gas-Solid Chromatography)

- differences in analyte distribution between carrier gas

and the surface of the adsorbent (stationary phase)

• Separation mechanism for Gas-Liquid Chromatography

- differences in analyte solubility in liquid phase

(stationary phase)

July 31, 2014 11

July 31, 2014 12

Adsorption Mechanism

• Stationary phase is an adsorbent

• Porous structures with large

surface area

• Interaction at surface area

Porous Layer Open Tubular (PLOT) Columns

Advantages

• Retention for high vapor pressure solutes

– No cryogenics needed

– Multi column, Valve switching, heart cutting techniques

• Variety adsorbents

– Porous polymers, alumina, molecular sieve, etc…

– Selectivity for isomeric compounds

– Gases & solvents separations

• Efficiency capillary PLOT

– Preferred over packed

– Packed benefits in specific applications

July 31, 2014 13

14

Tubing: SS, Glass

Length: 1-2 m

Particles: Polymer/Molsieve/ etc.

Partcle size: 125 – 200 µm

Tubing: Fused silica

Length: 5 – 60 m

Particles: Polymer/Molsieve

Particle size: < 2 µm

Packed and PLOT Columns

Packed PLOT

July 31, 2014

July 31, 2014

"Solid"

porous

layer

Fused silica

tubing

Ideal for the analysis of gases due to

their increased retention (k) and unique

selectivity (a) compared to WCOT

PLOT Columns

15

July 31, 2014 16

So Back to the Example: Analysis of LPG

50 m x 0.32 mm Al2O3/KCl

Carrier gas: H2

130 °C

PLOT Columns

Really Help!

Agilent PLOT Columns Portfolio

Porous Polymers

PoraBOND Q

PoraBOND U

PoraPLOT Q,U,S

HP-PLOT Q,U

GS-Q

PoraPLOT Q-HT

Zeolites

CP-Molsieve 5A

HP-Molesieve

Oxygenates

Lowox

GS-OxyPLOT

Alumina

Al2O3/KCl, HP-PLOT Al2O3/KCl

Al2O3/Na2SO4, HP-PLOT Al2O3 S

Select MAPD

GS-Alumina

Porous Silica

SilicaPLOT

GS-GasPro

Graphitized Carbon

CarboPLOT P7

CarboBOND

GS-CarbonPLOT

Select Permanent Gases

Select for Low Sulfur

July 31, 2014 17

Compounds & Columns

• Permanent gases

– Noble gases, O2, N2, H2, CO, CO2, CH4

• Light hydrocarbons

– C1 – C8, saturated, unsaturated,

– Aromatics, natural gas, C2, C3, C4 streams

• Volatile sulfur compounds

– H2S, COS, mercaptans,

– sulfides, disulfides

• Oxygenates

– Alcohols, ketones, ethers

• Solvents

– Oxygenates, aromatics, alkanes,

– chlorinated hydrocarbons

• Chlorinated and fluorinated hydrocarbons

Molsieve

Alumina Silica

Carbon Porous polymers

Porous polymers

Silica Porous polymers

Select Perm. Gases

Select Low Sulfur

Porous polymers

Silica

Lowox OxyPLOT

July 31, 2014 18

Porous Polymer PLOT columns

• HP-PLOT Q, GS-Q and PoraPLOT Q

• Separation ethane/ethylene, propane/propylene

% levels, not ppm impurities in C2, C3 matrix

• H2S and COS

Refinery gas analysis

100 ppm - %, not low ppm

• Pre-column with Molsieve columns for O2, N2, CH4, CO

• Poor C4 isomer separation

Alumina preferred

• Not sensitive to moisture

• Good choice for solvents and CFCs

July 31, 2014 19

Refinery Fuel Gas, Porous Polymer Separation

HP- PLOT Q

July 31, 2014 20

To Molsieve column for further separation

21

CP-PoraPLOT Q

Analysis of PH3 and AsH3 in C1-C3 hydrocarbons

July 31, 2014

Porous Polymer PLOT, Aqueous Injections

Retention times are the

same for all compounds

Samples containing water

can be analyzed

Isothermal & short cycle

time

Before

After 5 x 5 µL water, Splitless at 80 °C

methanol

ethanol

acetonitrile

acetone

pentane

July 31, 2014 22

23

Agilent “BOND” Technology

Particle size: 0.1- 2 µm

Number: > 1012

Particle PLOT Q PoraBOND Q

Bonded polymer layer

PLOT column Particle Trap

Detector

July 31, 2014

No particle traps

July 31, 2014 24

PoraPLOT Q/U and PoraBOND Q/U

PoraPLOT Q/U PoraBOND Q/U

Wide market acceptance Improved overall performance

Thick particle layer Thinner layer

Max 250 °C Max 300 °C

Higher bleed level Lower bleed + bake-out

Separation of CO2, C2’s Wide application range

Pre-column function Excellent aqueous samples

Particle Trap Zero particle loss

Solvent Analysis on PoraBOND Q

July 31, 2014 25

Alumina

• Detailed light hydrocarbon separation

• C1 – C6, extended to C8

• Saturate/unsaturate isomer separation

• KCl deactivation, largest market share

• Na2SO4 deactivation, C4 applications

• MAPD, higher response for unsaturates

• Sensitive to moisture in carrier gas, reversible with

conditioning. Advise Gas-Clean moisture filters!

• Long lifetime

July 31, 2014 26

July 31, 2014 27

Alumina Adsorbent and Columns

Separation depends on:

• Degree of hydrocarbon saturation

– Elution order: alkane, alkene, alkyne, (dialkenes)

• Type of deactivation

– KCl or Na2SO4

• Operating conditions

– Column flow and oven temperature

• Presence of water

– Al2O3 columns are sensitive to moisture in carrier gas: Gas Clean filters!

28

Selectivity Difference KCl and Na2SO4

1. Methane

2. Ethane

3. Ethene

4. Propane

5. Propene

6. Cyclopropane

7. Ethyne

8. Iso-butane

9. Propadiene

10. n-Butane

11. t-2-Butene

12. 1-Butene

13. Iso-butene

14. c-2-Butene

15. 1,3-Butadiene

16. Propyne

KCl

Na2SO4

July 31, 2014

29

Impurities in 1,3 Butadiene

15 min

50 m x 0.32 mm Al2O3 / KCl, 5 µm

100 -> 200 ºC, 6 ºC/min

1,3-Butadiene

Methylacetylene

Isobutane

Butane

Propane

Trans-2-butene

Iso-butene

1-Butene

c-2B=

July 31, 2014

Silica

• Light hydrocarbon separation, C1 – C4

• Light sulfurs, H2S, COS, mercaptans

• CFCs

• GasPro

• CP-SilicaPLOT

• Not sensitive to moisture in carrier gas

July 31, 2014 30

July 31, 2014

GS-GasPro: Inorganic Gases

31

July 31, 2014

GS-GasPro: Mercaptans

32

July 31, 2014

GS-GasPro: Halocarbons

33

Molecular Sieves

• Noble gases, Kr, He, Ar, Xe

• N2, O2, H2, CH4, CO

• CP-Molsieve 5 A

• HP-Molesieve

• Very sensitive to moisture/ CO2 in carrier gas/sample

– Conditioning needed

– Gas Clean Moisture filters in carrier gas essential

July 31, 2014 34

Permanent Gases and CO2

• H2, O2, N2, CO, CH4 and CO2

• Molsieve 5A, packed columns

• Thermal Conductivity Detection

• CO2 not on Molsieve

• Select for Permanent Gases, for academics

(not for HPI market)

– No valve switching

– CO2 level restricted

– Frequent conditioning

July 31, 2014 35

Select Permanent Gases

• O2, N2, H2, CH4, CO and CO2

• Dual column set-up with PoraBOND and Molsieve

• Inclusion of CO2

• No valve switching

• Needs reconditioning at regular intervals

• Targeted for academic market

July 31, 2014 36

37

Select for Permanent Gases PLOT Columns

Injection Detection (TCD)

CP-Molsieve 5A

CP-PoraBOND Q

Deactivated fused silica tubing

Universal “Y” Connectors

July 31, 2014

38

Select Permanent Gases/CO2 Fast CO2 and permanent gas analysis

Agilent Select Permanent

Gases/CO2

Carrier gas : He, 100 kPa, split 50 mL/min

Detector : µ-TCD

Oven : 50 °C isothermal

O2

N2

CH4 CH4

CO2 3.5 minutes analysis time

0 3 min

CP-Molsieve 5A CP-PoraBOND Q

Air

July 31, 2014

PLOT Columns for Oxygenate Analysis

• ppm light oxygenates in hydrocarbon streams

• C1 – C5 alcohols, ethers, ketones

• One column solution for ethylene, propylene, butylene feeds

• CP-Lowox

• OxyPLOT

• Highly sensitive to moisture in carrier gas

– Conditioning needed

– Gas Clean Moisture filters essential

July 31, 2014 39

Oxygenates in Hydrocarbons

July 31, 2014 40

• Oxygenates blended in gasoline

– Additives to boost octane content, prevent engine “knocking”

– MTBE, ETBE, Ethanol

– % level oxygenates

– GC analyses on Wax or TCEP polar liquid phase columns

• Oxygenate in intermediates (monomers, naphthas)

– Lower catalyst effectiveness, lower yield

– Higher catalyst costs

– More refinery downtime

– ppm level oxygenates

– GC analyses on Lowox, OxyPLOT columns, Agilent exclusives

– Advise Lowox

Analyzing Oxygenates in Hydrocarbon Matrix

• Low ppm concentration level oxygenates

• FID detection (MS rarely)

• High selectivity columns hydrocarbons/oxygenates

July 31, 2014 41

Hydrocarbons Oxygenates

Separation on Lowox

C6

C12

Acetone

Trace Methanol in Butadiene

July 31, 2014 42

20 ppm Methanol

1,3 Butadiene matrix

Oxygenates

Lowox

10 m x 0.53 mm

July 31, 2014

GS-CarbonPLOT

• Monolithic carbon molecular sieve

• Phase formed in situ

• Extended temperature limit of 360 °C

• Unique selectivity

43

July 31, 2014

1. Methylene chloride

2. Acetone

3. Carbon disulfide

4. Ethyl ether

5. Ethyl acetate

6. Benzene

GS-CarbonPLOT

30 m x 0.32 mm id, 1.5 µm

Carrier: He @ 30 cm/s

Oven: 125 °C for 2 min

125 to 350 °C at 20 °C/min

Injector: Split 1:20, 250 °C

Detector: MSD, SIM

6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00

1

2

3

4

5

6

Carbon-PLOT

Solvents

44

July 31, 2014

0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50

1. Methane

2. Acetylene

3. Ethylene

4. Ethane

5. Propyne

6. Propylene

7. Propane

GS-CarbonPLOT

30 m x 0.32 mm id, 1.5 µm

Carrier: He @ 30 cm/s

Oven: 125 °C for 2 min

125 to 225 °C at 20 °C/min

Injector: Split 1:20, 250 °C

Detector: MSD, SIM

1

2

3 4

5 6

7

Carbon-PLOT

C1 to C3 Hydrocarbon

Split Injector

45

Sulfur in Refinery Feeds and Propylene

The boiling point range of the hydrocarbon matrix determines the scope of the sulfur species present.

Sulfur components of concern:

• H2S, COS, Mercaptans, Thiophenes, Sulfides, Disulfides,

Example: H2S, COS and methyl mercaptan in propylene

Polypropylene catalysts are highly sensitive to sulfur poisoning:

Manufactures pay attention to sulfur components at few ppb in propylene.

Agilent Confidential

July 31, 2014

Introducing the Agilent J&W Select Low Sulfur GC

Column

New PLOT column, especially engineered for trace level sulfur in Propylene matrix:

Inertness: 100% response for H2S, methyl mercaptan

Selectivity: No quenching for COS because of the resolution from propylene

Stability: Zero particle shedding. Compatible with FPD, PFPD, SCD, AED

Dimensions: One dimension, 60 m x 0.32 mm id (p/n CP8575)

The new Select Low Sulfur PLOT column is designed to offer high

inertness, sensitivity and linearity for low level detection of active

sulfur and mercaptans in the HPI market.

The Select Low Sulfur improves data accuracy and can significantly

improve propylene yields and reduce catalyst costs providing

strong economic value and quality results for lab and process

management.

Agilent Confidential

July 31, 2014

Sulfurs & Propylene on Select Low Sulfur

48

3 4 5 6 7 8

Time [min]

Select Low Sulfur – 60 m*0.32 mm Overlay of H2S, COS and methyl mercaptan with hydrocarbons

H2S

CO

S

Pro

pyle

ne

Me

thyl m

erc

ap

tan

me

tha

ne

eth

an

e

eth

yle

ne

Air

ace

tyle

ne

pro

pa

ne

Conditions: Column: Select Low Sulfur, 60 m x 0.32 mm Temperature: 65 °C Carrier Gas: Helium, constant flow 2 mL/min Injector: 200 °C Detector: PFPD

July 31, 2014

Note that the hydrocarbon peaks are from the FID

Sulfur Components in Propylene Using PFPD

July 31, 2014 49

Detector quenching but not interfering

with COS quantification

500 ppbv H2S and COS

same peak height

High response of H2S

Agilent Confidential

Select Low Sulfur Landing Page:

http://www.chem.agilent.com/en-US/Products/columns-supplies/gc-gc-mscolumns/selectlowsulfur/Pages/SLSmore.aspx

Linearity on Select Low Sulfur, PFPD

50

R² = 0.9981

R² = 0.9977

R² = 0.9972

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0 10 20 30 40 50 60

sq

rt o

f A

rea

co

un

ts [

µV

.min

-1]

Concentration in ppb

Linearity on the Select Low Sulfur column of active sulfurs using GC-PFPD

H2S COS methyl mercaptan

Select Low Sulfur Landing Page:

http://www.chem.agilent.com/en-US/Products/columns-supplies/gc-gc-mscolumns/selectlowsulfur/Pages/SLSmore.aspx

Agilent Confidential

July 31, 2014

• UltiMetal: treated stainless steel with fused silica inertness

• Monomolecular layer

• Megabore, 0.53 mm id

• Robust and bendable Stainless steel

UltiMetal layer

Adsorbent or liquid phase

UltiMetal PLOT Columns for HPI

July 31, 2014 51

Agilent UltiMetal

PLOT columns

1. Molsieve 5A

2. Al2O3/KCL, Al2O3/Na2SO4, MAPD

3. PoraPLOT Q

PLOT Column with Integrated Particle Trap

• Zero particle shedding when using steep temperature gradients and pressure ranges

• Integrated to column – no unions and fittings

• Compatible with capillary GC and GC/MS systems - Agilent and non-Agilent

• Compatible with multi column valve switching systems and systems with CFT technology

– Particle traps integrated on both ends – supports back flush apps

• Similar selectivity, plates and peak shape performance to existing Agilent porous polymer PLOT columns

– Minimum method redevelopment required

– Available in a wide variety of our most popular porous polymer PLOT columns configurations

July 31, 2014 52

PLOT Column with Integrated Particle Trap

July 31, 2014 53

Integrated particle

trap at front and

back of the column

PLOT column

part

Proof of Performance

Regular PLOT Columns

With integrated Particle

Trap

• 150 to 250 °C at 20 °C/min

• Pressure 3x higher than optimal

pressure

• 15 cycles

• Carrier gas off and on 10 times

Spikes

July 31, 2014 54

PLOT Column with Integrated Particle Trap

July 31, 2014 55

This is where PLOT

column and

integrated particle

trap meet.

Example of Chromatographic Performance

July 31, 2014 56

Column: PoraBond Q PT, 30 m×0.25 mm,3 um

Carrier : Helium, 43 cm/s @90 ℃

Oven: : 90 - 140 °C at 10 °C/min

140 °C for 6 min

140 °C - 200 °C at 5 °C/min

200 °C for 10 min

Injection: Split, 250 °C, split ratio1:160

Detector: MSD, 280 °C Transfer line, full Scan at

m/z 30-350

1. Methyl alcohol

2. Acetaldehyde

3. Ethanol

4. Acetonitrile

5. Acetone

6. Methylene chloride

7. Isopropyl alcohol

8. 2-Propanamine

9. Ethyl formate

10. 1-Propanol

11. Ethyl ether

12. t-Butyl alcohol

13. 1,2-Ethanediol

14. Trichloromethane

15. 2-Butanone (MEK)

16. Ethyl acetate

17. sec-Butyl alcohol

18. MTBE

19. 2-Chlorobutane

20. 1-Butanol

21. Benzene

22. 1,1,1-Trichloroethane

23. 1-Chlorobutane

24. Carbon tetrachloride

25. Hexane

26. 1,4-Dioxane

27. Pyridine

28. Dimethyl formamide (DMF)

29. Isoamyl alcohol

30. Dimethyl sulfoxide (DMSO)

31. Toluene

32. Heptane

33. Paraldehyde

34. Chlorobenzene

35. Ethylbenzene

36. m-Xylene

37. p-Xylene

38. o-Xylene 6

6

2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00

4.80 5.00 5.20 5.40 5.60 5.80 6.00 6.20 6.40 6.60

5

7 9

10

11

2

1

3

4

5

7

8

9

10

11

12

13

14,15

16 17

18

20

21

23,24

22 25

26

27

28

29

30

31 32

19

33

34

35

36

37

38

8

Effect of conditioning time on PLOT columns

Blue = 2hr

Red = 6hr

Green = 24hr

Need to remove CO2 and H2O completely to

Get reproducible retention times and FID response

Carrier Gas Contamination & PLOT Columns

How does moisture effect PLOT columns?

min3 4 5 6 7 8

pA

5.25

5.5

5.75

6

6.25

6.5

6.75

7

FID1 B, Back Signal (071613\071613 2013-07-16 10-41-00\001F0101.D)

Met

hane

Eth

ane

Eth

ylen

e

Pro

pane

Pro

pyle

ne

N-B

utan

e

Ace

tyle

ne

Pro

pyne

FID1 B, Back Signal (071613\071613 2013-07-16 14-34-47\001F0101.D) FID1 B, Back Signal (071713\071713 2013-07-17 08-42-50\001F0101.D) Effect of conditioning time on PLOT columns

Blue = 2hr

Red = 6hr

Green = 24hr

Need to remove CO2 and H2O completely to

Get reproducible retention times and FID response

July 31, 2014 57

What is a ‘Carrier Gas’ Filter?

The Carrier Gas Filter is the new name for the Gas Clean GC/MS Filter. It is also known as a triple purifier because it can remove oxygen, moisture, and hydrocarbons. It includes indicators for oxygen and moisture in a single filter.

What about removing carbon dioxide?

Carbon dioxide is not as easily removed by the activated charcoal substrate that removes other hydrocarbons. Agilent offers a kit that includes two indicating filters for specifically removing carbon dioxide and water from the carrier gas.

Gas Clean CO2 Kit (p/n CP17983)

Gas Clean Carrier Gas Kit

Gas Clean CO2 Kit

July 31, 2014 58

Summary

• Agilent is the leader in PLOT column technology and supplies the largest selection of PLOT columns in the market for all gases and volatiles applications with dedicated columns for challenging analyses in the petrochemical industry.

• Fully QC tested to assure column to column reproducibility with the excellent peak shape performance and separation for the best data accuracy.

• Agilent PLOT columns come with the lowest levels of particle shedding for better baseline stability and trouble free analyses.

July 31, 2014 59