mono pressure process

Reader is reminded that this use case is only an example and should not be used for other purposes. Although this example is based on actual case it may not be considered as typical nor are the data used always the most accurate available. ProSim shall have no responsibility or liability for damages arising out of or related to the use of the results of calculations based on this example.

Copyright © 2006 ProSim, Labège, France - All rights reserved www.prosim.net

PROSIMPLUS HNO3 APPLICATION EXAMPLE

MONOPRESSURE NITRIC ACID

MANUFACTURING PROCESS

INTEREST OF THIS EXAMPLE

This example corresponds to the simulation of a nitric acid manufacturing unit by a monopressure process. It is a

rather traditional process of industrial production of nitric acid. The main modules specific to the simulator

ProSimPlus HNO3 are implemented here: absorption column of nitrous vapors, nitrous vapors condensers,

oxidation reactors, heat exchangers with oxidation volumes, nitrous vapor compressors, etc.

It is an example of pure simulation, without specification on the output streams.

The particular point which is detailed in this example is the use of an information stream to split a heat exchanger

between a temperature set and a simple exchanger in order to avoid a recycling stream.

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CORRESPONDING PROSIMPLUS HNO3 FILE HNO3 monopressure process.pmp

Monopressure nitric acid manufacturing process

Version: May, 12, 2006 Page: 2 / 21


TABLE OF CONTENTS

1. PROCESS MODELING 3

1.1. Process description 3

1.2. Process flowsheet 5

1.3. Specifications 5

1.4. Components 5

1.5. Thermodynamic model 6

1.6. Operating conditions 6

1.7. "Hints and Tips" 12

2. RESULTS 13

2.1. Comments on results 13

2.2. Mass and energy balances 13

2.3. Column C101 profiles 18

2.4. Column C102 profiles 20

3. REFERENCES 21




1. PROCESS MODELING

1.1. Process description

This example is extracted from the publications [1] and [2], which describe the process summarily.

The manufacture of nitric acid includes three principal stages:

��Oxidation of ammonia:

OH6NO4O5NH4 223 +→+

��Condensation of the water of combustion and oxidation of nitric oxide

( ) ( ).liqOHgazOH 22 ⇔

4222 ONNO2ONO2 ⇔⇔+

��Absorption of nitrogen dioxide and dinitrogen tetraoxide:

NOHNO2OHNO3 322 +⇔+

32242 HNO2OHO2/1ON ⇔++

The mathematical modeling of chemical equilibrium and kinetics of the above reactions are complex and

secondary reactions occur, in particular the formation of N2O3:

322 ONNONO ⇔+

The monopressure process (catalytic combustion and absorption at the same pressure) rest on the reaction:

NOHNO2OHNO3 322 +⇔+

whose principal characteristic is that, each time two molecules of nitric acid are formed, there is also production of

a nitric oxide molecule NO, that it is necessary to oxide in NO2 then to absorb and so on. These successive

oxidations are done mainly in gas phase, in absorption towers where are in parallel carried out the reaction of

formation of the nitric acid and that of oxidation of NO:

22 NOO2/1NO ⇔+

In this process, condensation and absorption are done with the same pressure as oxidation, between 0.5 and

approximately 1 Mpa. There is thus one compressor and the tower of absorption is equipped in its lower part with a

stage of denitration.

The process diagram is provided hereafter.

The liquid ammonia is vaporized by cooling water (E101), then heated (E102), filtered and sent in a air-ammonia

mixer (M101). On the other side, the filtered atmospheric air is compressed (K101), then divided into two streams

in the valve V103, the primary air (Air S06) which goes to the air-ammonia mixer (M101) and secondary air which




goes to the bleacher (C102). Previously, a fraction of the air is taken (Air S03) for the instrumentation, in V102

valve. The air-ammonia mixture is directed towards the NH3 converter (R101).

The model of the reactor takes into account two reactions:

OH6NO4O5NH4 223 +→+

OH6N2O3NH4 2223 +→+

The gas after combustion contains nitrogen oxides, nitrogen and oxygen. Its significant heat is recovered in a

series of heat exchangers (E103, E104, E105, E106). After condensation (E107), a large quantity of weak acid is

formed and sent to the absorption tower (C101). The gas mixed with the outgoing air of the bleacher (C102) on the

level of the M103 mixer is directed on the perforated plates of the absorption column (C101) equipped in particular

with cooling coils. Process water is introduced at the top and the acid, with the desired concentration, is recovered

at its bottom. This acid goes then to the bleaching column (C102) equipped with plates. There is a stripping by

secondary air (Air S08). The outgoing gases at the top of the C101 absorber are sent in a series of gas-gas heat

exchangers (E108, E109, E105), then mixed with a small quantity of ammonia in order to react in a catalytic reactor

making it possible to reduce the content NOx in tail gas. In reactor (R102), operated around 250 °C a set of

reactions occurs which can be modeled by the two following reactions:

OH6N5NO6NH4 223 +→+ and OH12N7NO6NH8 2223 +→+

The tail gases with very low NOx content are then sent in an expander (T101) and finally to the stack.

In parallel, steam is produced by heat recovery on the process (not modeled in this example).

Moreover, cooling water passes successively in the E107 condenser then in the E101 exchanger.

The objective of this process is to produce 1.000 tons per day of nitric acid (equivalent 100%) with a concentration

of 58% mass.




1.2. Process flowsheet

E101

E102

V101

M101

R101

E103

E112E104

O101 E105

E109

O102 E106 O103

E108

V103

E107

O104

M102

M103

C101

C102P101

E111

T101

R102

E107 CW

E110

K101

V102

V104M104

Monopressure process flowsheet

1.3. Specifications

In this example there is no specification imposed on the output streams (the implementation of such specifications

is presented in the E02 example: Dual-Pressure Nitric Acid Manufacturing Process). We only simulate here the

operation of a unit for a set of operating parameters and for given process feed streams.

1.4. Components Properties of the components involved in the simulation are taken from the standard database, provided with

ProSimPlus HNO3 software. Eight components are taken here into account:

��Ammonia (NH3)

��Water (H20)

��Nitric acid (HNO3)

��Nitric oxide (NO)

��Nitrogen dioxide (NO2)




��Nitrogen tetraoxide (N2O4)

��Nitrogen (N2)

��Oxygen (O2)

1.5. Thermodynamic model

For the main part of the process the thermodynamic model taken into account is the default model of the software

ProSimPlus HNO3 (see User's manual - chapter 2).

However, at the level of the cooling water line, a specific model for water is used.

1.6. Operating conditions

��Process feed

Ammonia

(NH3 S01)

Air

(Air LP)

Process water

(Water S01)

Return

condensates

(Water S02)

Cooling water

(CW S01)

Temperature (°C) 10 25 25 25 25

Pressure (Bar) 14 1 6.5 6.6 4.2

NH3 11 874 - - - -

N2 - 162 426.2 - - -

O2 - 49 022.0 - - -

Partial

mass

flowrate

(kg/h) H2O 24 1 961.093 3 555 12 520 2 000 000

��Reactor R101

Operating parameters Value

Type of reactor simple

5 O2 + 4 NH3 � 6 H20 + 4 NO 96.09 Ammonia conversion rate (%)

3 O2 + 4 NH3 � 6 H20 + 2 N2 3.91

Pressure drop (bar) 0.05

Output temperature adiabatic




��Heat exchangers

Hot stream Cold stream

Name Output

Temperature

(C)

Pressure

drop (bar)

Reaction

volume

(m3)

Output

Temperature

(C)

Pressure

drop (bar)

Reaction

volume (m3)

E101 - 0.05 - 34 4.80 -

E105 250 0.05 - - 0.05 -

E106 175 0.05 7.4873 - 0.05 -

E108 100 0.05 - - 0.02 -

For the heat exchanger in which the chemical reactions are taken into account (E106, reaction volume not

equal to zero), one adopts:

- a plug-flow pattern

- an oxidation efficiency of 1

- the calculation of the oxidation reaction rate by the model of Koukolik

- the calculation of the dimerisation equilibrium constant by the model of Koukolik.

��Simple heat exchangers

Name Type

Output

Temperature

(C)

Pressure drop

(bar)

Reaction volume

(m3)

E102 Cooler/heater 120 1.50 -


E104 Cooler/heater 350 0.05 1.9514

E107 CW Simple heat exchanger - 0.05 -





For the heat exchanger in which the chemical reactions are taken into account (E104, reaction volume not

equal to zero), one adopts:







- the calculation of the dimerisation equilibrium constant by the model of Koukolik.

��Condenser E107


Length of the tubes (m) 9

Number of tubes 2 100

Vapor flow Inside the tubes

Internal diameter of the tubes (mm) 25.4

Temperature of cooling water (C) 25

Cooling water flowrate (T/h) 2 000

Flow direction Counter-current

Global heat exchange coefficient for absorption (Kcal/h/m2/K) 215

Global heat exchange coefficient for oxidation (Kcal/h/m2/K) 290


Moreover, one adopts:


- the calculation of the dimerisation equilibrium constant by the model of Koukolik

- the calculation of the constant of absorption of N2O4 in water by the method based on the

equation of Miller (bubble caps).

��Compressor K101


Isentropic efficiency 0.845

Mechanical efficiency 1

Discharge pressure (bar) 7.8

Taking into account of the chemical reaction not




��Volumes of oxidation

Name Volume of oxidation

(m3)

Pressure drop (bar)

O101 9 0.01

O102 28 0.01

O103 6 0.01

O104 2 0.01






- an adiabatic operation.

��Column C101


Column type Absorption

Number of stages 35

Weak acid (Acid S02) plate feed 24

(plates numbered from top to bottom)

Water (Water S0) plate feed 2

(plates numbered from top to bottom)

Column diameter (m) 6.1

Hole diameter (mm) 2

Free section 2.60%

Pressure drop in the column (bar) 0.77


Version: May, 12, 2006 Page: 10 / 21


Plate Temperature (°C)

Volume of oxidation

(m3) Spacing (m) Plate Temperature

(°C)

Volume of oxidation

(m3) Spacing (m)

1 (top) 29.4 51 2.25 19 42.1 35.6 1.21

2 - “ “ 20 42.9 “ “

3 30.0 “ “ 21 43.6 “ “

4 30.6 58.5 “ 22 44.4 “ “

5 31.4 “ 2.00 23 45.2 “ “

6 32.2 “ “ 24 45.9 “ “

7 33.0 “ “ 25 46.7 “ “

8 33.8 51.6 “ 26 47.4 “ “

9 34.5 “ “ 27 48.2 “ “

10 35.3 “ 1.75 28 48.9 “ “

11 36.1 “ “ 29 49.7 “ “

12 36.8 “ “ 30 50.5 “ “

13 37.6 35.6 “ 31 51.2 “ “

14 38.3 “ “ 32 52.0 “ “

15 39.1 “ 1.21 33 52.9 79.5 2.70

16 39.8 “ “ 34 54.5 58.5 2.00

17 40.6 “ “ 35 (bottom)

57.0 58.5 2.00

18 41.4 “ “


- the calculation of the temperature profile in the column from the provided temperatures

- the dissolution of NOx is not taken into account and for NOx in liquid phase the oxidation

of NO is taken to 0%



- the calculation of the equilibrium of the system nitrogen oxides–water–nitric acid by the

equation of Zhidkov

- the efficiency of oxidation of each plate is equal to 1

- the hydrodynamic model on each plate is that of a plug-flow reactor

- the absorption efficiency on each plate is calculated by the equation of Atroshenko 2.


Version: May, 12, 2006 Page: 11 / 21


��Column C102


Type of column Absorber

Number of theoretical stages 8

Pressure drop in the column (bar) 0.41

��Pump P101


Exhaust pressure (bar) 7.5

Volumetric efficiency 0.65

Mechanical efficiency 1

��Stream splitters

Name Type Operating parameters Value

V101 3 ways valve Mass flowrate of stream NH3 S05 (kg/H) 87.4

V102 3 ways valve Mass flowrate of stream Air S03 (kg/H) 1006.8

V103 3 ways valve Splitting rate for the stream Air S06 (%) 79.93111

V104 3 ways valve Splitting rate for the stream CW S03 (%) 80

��Reactor R102


Type of reactor simple

Conversion rate of NO (%) 6 NO + 4 NH3 � 6 H20 + 5 N2 90.0

Conversion rate of NO2 (%) 6 NO2 + 8 NH3 � 12 H20 + 7 N2 28.5


Output temperature adiabatic


Version: May, 12, 2006 Page: 12 / 21


��Expander T101


Exhaust pressure (bar) 1.03

Isentropic efficiency 0.83

1.7. "Hints and Tips"

For the nitrous vapors condenser E107 modeling, an information stream (E107 duty) is used to transfer information

“heat duty” to a simple heat exchanger module. This one will calculate the temperature increase of the cooling

water stream (CW S01). The information streams make it possible in ProSimPlus HNO3 to transfer any type of

parameter of a module to another one. It can be for example an operating parameter of a module (data), a result of

the calculation of a module, or a parameter of a stream (using the MEASURE module). It is in addition possible to

make simple calculations on the information streams using the HANDLER module, before reintroducing them in a

module.

In this example of simulation, most of the heat exchangers are simulated as on the industrial plant by coupling a

hot stream and a cold stream. However, it is also possible to simulate an exchanger by splitting the hot stream and

the cold stream, it is what is made in E107 condenser. This way of modeling a two-stream heat exchanger enables

to avoid a stream recycle that would penalize the calculation by splitting the heat exchanger in two parts. This way

of modeling is frequently used in process simulation. It is illustrated in the example of application of ProSimPlus

E02 (Cyclohexane Plant). It should be noted also that the order of calculation of the modules (the sequence of

calculation), automatically given by ProSimPlus HNO3, takes account of the presence of the information streams.

In this example, the module E107 is calculated before the module E107 CW in order to have the heat duty required

for the calculation of this last.


Version: May, 12, 2006 Page: 13 / 21


2. RESULTS

2.1. Comments on results

Since the flowsheet contains several recycling streams, it is necessary to initialize two streams. The streams which

one chose to initialize are streams PG S07 and Air S09. From there, the calculation sequence (the order of

calculation of the modules) is generated automatically.

The convergence of the cycle is obtained in 2 iterations, that is to say 4 passages in the Maximum Cyclic Network.

Regarding the absorption column (C101), convergence is obtained in 3 iterations, without any initialization.

Regarding the bleaching column (C102), it converges in 6 iterations, also without any initialization.

2.2. Mass and energy balances

Streams Acid production Acid S01 Acid S02 Acid S03 Acid S04 From E111 E107 P101 C101 C102 To >>> P101 C101 C102 E111 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 0 0 0 0 0 WATER 722.908657 396.6531571 396.6531571 724.583951 722.908657 NITRIC ACID 1000.047136 317.4994765 317.4994765 1034.546471 1000.047136 NITRIC OXIDE 0 0 0 0 0 NITROGEN DIOXIDE 0 0 0 0 0 NITROGEN TETROXIDE 0 0 0 0 0 NITROGEN 0.453006404 0 0 0 0.453006404 OXYGEN 0.757082434 0 0 0 0.757082434 Total flowrate t/d 1724.165882 714.1526336 714.1526336 1759.130422 1724.165882 Total flowrate kmol/h 2334.894571 1127.335029 1127.335029 2359.921849 2334.894571 Total flowrate m3/h 54.28099682 24.3139225 24.31415125 55.94119064 55.14015165 Physical state Liquid Liquid Liquid Liquid Liquid Temperature C 45 65.6574402 65.66759008 57 59.82806917 Pressure bar 7.599997946 7.249998041 7.499997973 7.239998043 7.649997933 Enthalpy kW -167645.4732 -83471.21405 -83470.95428 -168448.9755 -166828.3745 Vapour fraction


Version: May, 12, 2006 Page: 14 / 21


Streams Air LP Air S01 Air S02 Air S03 Air S04 From Air feed K101 E110 V102 V102 To K101 E110 V102 >>> E106 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 0 0 0 0 0 WATER 47.06653398 47.06653398 47.06653398 0.222045564 46.84448841 NITRIC ACID 0 0 0 0 0 NITRIC OXIDE 0 0 0 0 0 NITROGEN DIOXIDE 0 0 0 0 0 NITROGEN TETROXIDE 0 0 0 0 0 NITROGEN 3898.253523 3898.253523 3898.253523 18.39077216 3879.862751 OXYGEN 1176.535789 1176.535789 1176.535789 5.55053731 1170.985251 Total flowrate t/d 5121.855846 5121.855846 5121.855846 24.16335503 5097.692491 Total flowrate kmol/h 7438.992158 7438.992158 7438.992158 35.09489802 7403.89726 Total flowrate m3/h 184408.6462 45444.75699 29939.85648 141.2471189 29798.60936 Physical state Vapour Vapour Vapour Vapour Vapour Temperature C 25 299.9519976 102 102 102 Pressure bar 0.99999973 7.799997892 7.749997906 7.749997906 7.749997906 Enthalpy kW -7311.986587 9566.085921 -2648.046449 -12.49267617 -2635.553772 Vapour fraction 1 1 1 1 1

Streams Air S05 Air S06 Air S07 Air S08 Air S09 From E106 V103 V103 E108 C102 To V103 M101 E108 C102 M103 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 0 0 0 0 0 WATER 46.84448841 37.44331956 9.401168851 9.401168851 11.07646403 NITRIC ACID 0 0 0 0 34.49932639 NITRIC OXIDE 0 0 0 0 0 NITROGEN DIOXIDE 0 0 0 0 0 NITROGEN TETROXIDE 0 0 0 0 0 NITROGEN 3879.862751 3101.217363 778.6453877 778.6453877 778.1923813 OXYGEN 1170.985251 935.9815093 235.003742 235.003742 234.2466597 Total flowrate t/d 5097.692491 4074.642192 1023.050299 1023.050299 1058.014831 Total flowrate kmol/h 7403.89726 5918.017264 1485.879997 1485.879997 1510.907272 Total flowrate m3/h 40686.50405 32521.17431 8165.329743 6026.124666 5727.807686 Physical state Vapour Vapour Vapour Vapour Vapour Temperature C 235.7686327 235.7686327 235.7686327 100 56.95858407 Pressure bar 7.699997919 7.699997919 7.699997919 7.649997933 7.239998043 Enthalpy kW 5531.676766 4421.530641 1110.146125 -553.2016122 -2173.802556 Vapour fraction 1 1 1 1 1


Version: May, 12, 2006 Page: 15 / 21


Streams CW S01 CW S02 CW S03 CW S04 CW S05 From >>> E107 CW V104 E101 V104 To E107 CW V104 E101 M104 M104 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 0 0 0 0 0 WATER 48000.30797 48000.30797 38400.24638 38400.24638 9600.061594 NITRIC ACID 0 0 0 0 0 NITRIC OXIDE 0 0 0 0 0 NITROGEN DIOXIDE 0 0 0 0 0 NITROGEN TETROXIDE 0 0 0 0 0 NITROGEN 0 0 0 0 0 OXYGEN 0 0 0 0 0 Total flowrate t/d 48000.30797 48000.30797 38400.24638 38400.24638 9600.061594 Total flowrate kmol/h 111016.7478 111016.7478 88813.39821 88813.39821 22203.34955 Total flowrate m3/h 2005.604375 2012.015487 1609.61239 1608.387466 402.4030975 Physical state Liquid Liquid Liquid Liquid Liquid Temperature C 25 35.40831105 35.40831105 33.17156043 35.40831105 Pressure bar 4.199998865 4.149998878 4.149998878 4.099998892 4.149998878 Enthalpy kW -1356824.586 -1332644.306 -1066115.444 -1070274.822 -266528.8611 Vapour fraction

Streams CW S06 NH3 S01 NH3 S02 NH3 S03 NH3 S04 From M104 >>> E101 E102 V101 To >>> E101 E102 V101 M101 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 0 284.9778284 284.9778284 284.9778284 282.8844462 WATER 48000.30797 0.576003696 0.576003696 0.576003696 0.571772504 NITRIC ACID 0 0 0 0 0 NITRIC OXIDE 0 0 0 0 0 NITROGEN DIOXIDE 0 0 0 0 0 NITROGEN TETROXIDE 0 0 0 0 0 NITROGEN 0 0 0 0 0 OXYGEN 0 0 0 0 0 Total flowrate t/d 48000.30797 285.5538321 285.5538321 285.5538321 283.4562187 Total flowrate kmol/h 111016.7478 698.5478067 698.5478067 698.5478067 693.4164335 Total flowrate m3/h 2010.784935 11.9010776 2965.487195 2943.703401 Physical state Liquid Liquid Liq./Vap. Vapour Vapour Temperature C 33.61911767 10 34 120 120 Pressure bar 4.099998892 13.99999622 9.199997514 7.699997919 7.699997919 Enthalpy kW -1336803.683 -13078.90835 -8919.515736 -8296.145332 -8235.203737 Vapour fraction 0.999377112 1 1


Version: May, 12, 2006 Page: 16 / 21


Streams NH3 S05 NH3 S06 PG S01 PG S02 PG S03 From V101 E112 M101 R101 E103 To E112 M102 R101 E103 E104 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 2.093382266 2.093382266 282.8844462 0 0 WATER 0.004231192 0.004231192 38.01509207 486.8760978 486.8760978 NITRIC ACID 0 0 0 0 0 NITRIC OXIDE 0 0 0 478.9242924 478.9242924 NITROGEN DIOXIDE 0 0 0 0 0 NITROGEN TETROXIDE 0 0 0 0 0 NITROGEN 0 0 3101.217363 3110.31426 3110.31426 OXYGEN 0 0 935.9815093 281.9829628 281.9829628 Total flowrate t/d 2.097613458 2.097613458 4358.098411 4358.097613 4358.097613 Total flowrate kmol/h 5.131373198 5.131373198 6611.433697 6784.457202 6784.457202 Total flowrate m3/h 21.78379399 29.5166218 35671.16062 89461.45361 54389.44149 Physical state Vapour Vapour Vapour Vapour Vapour Temperature C 120 180 220.0270068 924.2394575 450 Pressure bar 7.699997919 6.54999823 7.599997946 7.54999796 7.499997973 Enthalpy kW -60.9415954 -57.55504786 -3813.674778 -3813.673275 -34240.58572 Vapour fraction 1 1 1 1 1

Streams PG S04 PG S05 PG S06 PG S07 PG S08 From E104 O101 E105 O102 E106 To O101 E105 O102 E106 O103 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 0 0 0 0 0 WATER 486.8760978 486.8760978 486.8760978 486.8760978 486.8760978 NITRIC ACID 0 0 0 0 0 NITRIC OXIDE 443.0541023 333.237625 333.237625 181.1809487 161.0475003 NITROGEN DIOXIDE 54.99612525 223.3656295 223.3366844 456.4668549 486.0240427 NITROGEN TETROXIDE 0.000226523 0.00188495 0.030830071 0.034703009 1.346218689 NITROGEN 3110.31426 3110.31426 3110.31426 3110.31426 3110.31426 OXYGEN 262.8568012 204.3021157 204.3021157 123.2247486 112.4894949 Total flowrate t/d 4358.097613 4358.097613 4358.097613 4358.097613 4358.097614 Total flowrate kmol/h 6759.552468 6683.306267 6683.293159 6577.718634 6563.146097 Total flowrate m3/h 47009.60857 49633.76337 39337.31087 43107.12057 33362.90531 Physical state Vapour Vapour Vapour Vapour Vapour Temperature C 350 391.3980884 250 308.5481984 175 Pressure bar 7.449997987 7.439997989 7.389998003 7.379998006 7.329998019 Enthalpy kW -41059.03089 -41059.03089 -49391.10639 -49391.10607 -57558.33661 Vapour fraction 1 1 1 1 1


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Streams PG S09 PG S10 PG S11 PG S12 TG S01 From O103 E107 O104 M103 C101 To E107 O104 M103 C101 E108 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 0 0 0 0 0 WATER 486.8760978 44.83661247 44.83661247 55.91307649 16.0316407 NITRIC ACID 0 0 0 34.49932639 1.177197379 NITRIC OXIDE 142.5644048 141.8785615 125.8582112 125.8582112 1.822550919 NITROGEN DIOXIDE 514.5327866 231.3125928 263.2463569 263.2463569 0.463094038 NITROGEN TETROXIDE 1.175847459 53.64236882 46.27107651 46.27107651 0.00191831 NITROGEN 3110.31426 3110.31426 3110.31426 3888.506641 3888.506641 OXYGEN 102.6342176 61.96089405 53.41876453 287.6654242 134.7209912 Total flowrate t/d 4358.097614 3643.94529 3643.945282 4701.960113 4042.724034 Total flowrate kmol/h 6550.390457 5241.363685 5233.578798 6744.48607 5999.874011 Total flowrate m3/h 33882.20491 20365.3366 20779.84707 26508.93082 23327.45565 Physical state Vapour Vapour Vapour Vapour Vapour Temperature C 182.2396884 65.6574402 72.59012207 69.1048027 29.4 Pressure bar 7.319998022 7.249998041 7.239998043 7.239998043 6.469998251 Enthalpy kW -57558.33661 1732.473715 1732.473716 -441.3288666 -2238.432867 Vapour fraction 1 1 1 1 1

Streams TG S02 TG S03 TG S04 TG S05 TG S06 From E108 E109 E105 M102 R102 To E109 E105 M102 R102 T101 Partial flowrates t/d t/d t/d t/d t/d AMMONIA 0 0 0 2.093382266 1.40731213 WATER 16.0316407 16.0316407 16.0316407 16.03587189 17.1244794 NITRIC ACID 1.177197379 1.177197379 1.177197379 1.177197379 1.177197379 NITRIC OXIDE 1.822550919 1.822550919 1.822550919 1.822550919 0.182255092 NITROGEN DIOXIDE 0.464821724 0.464986475 0.465012266 0.465012266 0.332483814 NITROGEN TETROXIDE 0.000190623 2.58712E-05 8.04297E-08 8.04297E-08 3.6602E-08 NITROGEN 3888.506641 3888.506641 3888.506641 3888.506641 3889.876931 OXYGEN 134.7209912 134.7209912 134.7209912 134.7209912 134.7209912 Total flowrate t/d 4042.724034 4042.724034 4042.724034 4044.821647 4044.82165 Total flowrate kmol/h 5999.874794 5999.874868 5999.87488 6005.006253 6005.485896 Total flowrate m3/h 26044.89809 28904.94428 42353.57623 42648.37158 43663.2908 Physical state Vapour Vapour Vapour Vapour Vapour Temperature C 63.60017079 100 269.3707912 269.2633248 273.3824657 Pressure bar 6.449998257 6.43999826 6.389998273 6.349998284 6.249998311 Enthalpy kW -575.0727694 1197.90261 9529.97837 9472.423332 9472.422883 Vapour fraction 1 1 1 1 1


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Streams TG S07 Water S01 Water S02 From T101 >>> >>> To H-102 C101 C101 Partial flowrates t/d t/d t/d AMMONIA 1.40731213 0 0 WATER 17.1244794 85.32054742 300.4819279 NITRIC ACID 1.177197379 0 0 NITRIC OXIDE 0.182255092 0 0 NITROGEN DIOXIDE 0.332483814 0 0 NITROGEN TETROXIDE 3.6602E-08 0 0 NITROGEN 3889.876931 0 0 OXYGEN 134.7209912 0 0 Total flowrate t/d 4044.82165 85.32054742 300.4819279 Total flowrate kmol/h 6005.485896 197.3322692 694.964841 Total flowrate m3/h 177362.1524 3.565546916 12.55714413 Physical state Vapour Liquid Liquid Temperature C 92.71229898 25 25 Pressure bar 1.029999722 6.499998243 6.599998216 Enthalpy kW 574.4929786 -15659.59244 -55149.95707 Vapour fraction 1

2.3. Column C101 profiles

Recovered duty profile

0

1 000

2 000

3 000

4 000

5 000

6 000

0 5 10 15 20 25 30 35

Stage

Hea

t dut

y (k

W)


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NOx content profile

0

10 000

20 000

30 000

40 000

50 000

60 000

70 000

0 5 10 15 20 25 30 35

Stage

NO

x co

nten

t (pp

mv)

Liquid nitric acid mass fraction profile

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 5 10 15 20 25 30 35

Stage

HN

O3

mas

s fr

actio

n


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Partial mass flowrates in gas phase profiles

0

100

200

300

400

500

600

0 5 10 15 20 25 30 35

Stage

Flow

rate

(t/d

)

NONO2N2O4NOX (NO+NO2+2*N2O4)

2.4. Column C102 profiles

Liquid mass fraction profiles

0,4

0,42

0,44

0,46

0,48

0,5

0,52

0,54

0,56

0,58

0,6

0 1 2 3 4 5 6 7 8 9

Stage

Mas

s fr

actio

ns

WATER

NITRIC ACID


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Vapour phase mass fraction profile

0,032

0,032

0,033

0,033

0,034

0,034

0,035

0 1 2 3 4 5 6 7 8 9

Stage

Mas

s fr

actio

ns

NITRIC ACID

3. REFERENCES

[1] Badoual C.

Acide Nitrique

Techniques de l'Ingénieur, traité de Génie des Procédés

[2] Clarke Stephen I. and Mazzafro William J.

Nitric Acid

Kirk-Othmer Encyclopedia of Chemical Technology, 4th edition

[3] Joulia X.

"Contribution au développement d'un programme général de simulation. Application à l'analyse du

fonctionnement d'un atelier de production d'acide nitrique"

Thèse INPT 1981

mono pressure process

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