This document provides an overview of the key components and processes in an ammonia plant. It describes the desulphurization process to remove sulfur from natural gas and naphtha feeds. It then explains the multi-step reforming process used to produce hydrogen and other gases from these feeds, including pre-reforming, primary reforming, and secondary reforming. The shift reaction process is also summarized, which converts carbon monoxide into carbon dioxide. Overall temperatures, pressures, catalysts and reactions for each major unit are outlined to concisely explain the production of ammonia.

1. SIMPLE WAY TOSIMPLE WAY TO
UNDERSTAND AMMONIAUNDERSTAND AMMONIA
PLANTPLANT
BYBY
PREM BABOOPREM BABOO
SR. MANAGER(PROD)SR. MANAGER(PROD)
NATIONAL FERTILIZERS LTD,VIJAIPUR, INDIANATIONAL FERTILIZERS LTD,VIJAIPUR, INDIA

2. SIMPLE WAY TO UNDERSTANDSIMPLE WAY TO UNDERSTAND
AMMONIA PLANTAMMONIA PLANT
 TECHNOLOGY HALDOR TOPSOETECHNOLOGY HALDOR TOPSOE
 CAPACITY 1750/1864 TPDCAPACITY 1750/1864 TPD
 FEED NG AND NEPTHAFEED NG AND NEPTHA
 ENERGY 7.2GCAL/TON OF AMMONIAENERGY 7.2GCAL/TON OF AMMONIA
ON NGON NG
 7.36 GCAL/TON OFAMMONIA IN7.36 GCAL/TON OFAMMONIA IN
 CASE OF MIXED FEEDCASE OF MIXED FEED

4. INGREDIENT FOR AMMONIAINGREDIENT FOR AMMONIA
 TO PRODUCE AMMONIA WE REQUIRETO PRODUCE AMMONIA WE REQUIRE
HH22 AND NAND N22
 HH22 WE GET FROM NG AND WATERWE GET FROM NG AND WATER
 NN22 WE GET FROM AIRWE GET FROM AIR
 NG CONTAINS ABOUT 92%CHNG CONTAINS ABOUT 92%CH44
 NEPTHA CONTAINS HIGHERNEPTHA CONTAINS HIGHER
HYDROCAREBONHYDROCAREBON

5. BLOCK DIGRAM OF AMOONIABLOCK DIGRAM OF AMOONIA
PLANTPLANT
DESULPHERISATION REFORMING
SHIFT REACTION CO2 REMOVAL AREA
SYNTHESIS
COMP HOUSE
CO2 TO UREA
AMM TO UREA
AND METHNATION

6. DESULPHERISATIONDESULPHERISATION
AIMAIM
 TO REMOVE ALL SULPHERTO REMOVE ALL SULPHER
COMING WITH NG AND NEPTHACOMING WITH NG AND NEPTHA
 SULPHER IS POISIONOUS FOR THESULPHER IS POISIONOUS FOR THE
DOWNSTREAM CATALAYSTDOWNSTREAM CATALAYST
 IT CONSISTS OF TWO STEPSIT CONSISTS OF TWO STEPS

7. HYDROGENATIONHYDROGENATION
 IN THIS VESSLE NG AND NEPTHA AREIN THIS VESSLE NG AND NEPTHA ARE
BROUGHT IN CONTACT WITHBROUGHT IN CONTACT WITH
HYDROGEN SO THAT ORGANICHYDROGEN SO THAT ORGANIC
SULPHER GETS CONVERTED INTOSULPHER GETS CONVERTED INTO
INORGANIC SULPHER WHICH ISINORGANIC SULPHER WHICH IS
SUBSEQUENTLY REMOVED IN ZNOSUBSEQUENTLY REMOVED IN ZNO
ABSORBERABSORBER
 CATALYST NIMO –FOR NGCATALYST NIMO –FOR NG
 COMO -FOR NAPHTHACOMO -FOR NAPHTHA

8. HYDRODE-SULPHERISATIONHYDRODE-SULPHERISATION
 ALL ORGANIC SULPHER GETSALL ORGANIC SULPHER GETS
CONVERTED IN H2SCONVERTED IN H2S
HDS
NIMO
NG
H2
OUTLET
RSH +H2 =RH +H2S
R1SSR2 +H2 = R1H +R2H +H2S

9. ZnO ABSORBERZnO ABSORBER
 TWO BEDS ARE INSTALLED IN SERIESTWO BEDS ARE INSTALLED IN SERIES
 CATALYST USED IS = ZnOCATALYST USED IS = ZnO
 ZnO+HZnO+H22S = ZnS + HS = ZnS + H22OO
 SULPHER AT THE OUTLET OF THESE VESSLE ARESULPHER AT THE OUTLET OF THESE VESSLE ARE
LESS THAN .01PPMLESS THAN .01PPM
 INCREASING SULPHER CONTENT GIVE THEINCREASING SULPHER CONTENT GIVE THE
INDICATION THAT BEDS ARE GETTING EXHUSTEDINDICATION THAT BEDS ARE GETTING EXHUSTED
AND THEY REQUIRE CHANGEAND THEY REQUIRE CHANGE
 FIRST BED CAN BE BYPASSED AND CATALYST CANFIRST BED CAN BE BYPASSED AND CATALYST CAN
BE CHANGED ON LINE A SPECIAL BED OF CopperBE CHANGED ON LINE A SPECIAL BED OF Copper
BASEDCATALYST IS INSTALLED AT THE BOTTOM OFBASEDCATALYST IS INSTALLED AT THE BOTTOM OF
THE FIRST BED TO ADSORB ANY ORGANIC SULPHERTHE FIRST BED TO ADSORB ANY ORGANIC SULPHER
IF IT SLIPS FROM HYDROGEATION BEDIF IT SLIPS FROM HYDROGEATION BED

10. DESULPHERISATIONDESULPHERISATION
ZnO +HZnO +H22S = ZnS +HS = ZnS +H22
ZnO ZnO
TO REFORMER
FROM HDS

11. REFORMINGREFORMING
 AIMAIM
 TO REFORM NG AND NEPTHA IN TO HTO REFORM NG AND NEPTHA IN TO H22
CO AND COCO AND CO22 REFORMING IS DONE WITHREFORMING IS DONE WITH
THE HELP OF STEAM THATIS WHY IT ISTHE HELP OF STEAM THATIS WHY IT IS
CALLED STEAM REFORMING ITCALLED STEAM REFORMING IT
CONSIST OF THREE STEPSCONSIST OF THREE STEPS

12. STEPS OF REFORMINGSTEPS OF REFORMING
 PREREFORMERPREREFORMER
 PRIMARY REFORMERPRIMARY REFORMER
 SECONDRY REFORMERSECONDRY REFORMER

13. CONDITION OF REFORMINGCONDITION OF REFORMING
 REFORMING IS AN ENDOTHERMIC REACTIONREFORMING IS AN ENDOTHERMIC REACTION
 IT MEANS THAT HEAT WILL HAVE TO BEIT MEANS THAT HEAT WILL HAVE TO BE
SUPPLIED TO MOVE THE REACTION INSUPPLIED TO MOVE THE REACTION IN
FORWARD DIRECTIONFORWARD DIRECTION
 MAJOR PORTION OF REFORMING IS DONE INMAJOR PORTION OF REFORMING IS DONE IN
PRIMARY REFORMER THIS REACTION ISPRIMARY REFORMER THIS REACTION IS
CARRIED OUT IN A FURNACE OPERATINGCARRIED OUT IN A FURNACE OPERATING
CONDITIONS ARE VERY INTENCECONDITIONS ARE VERY INTENCE

14. REACTIONS OF REFORMINGREACTIONS OF REFORMING
 CnH2n+2 +2H20 = Cn-1H2n +COCnH2n+2 +2H20 = Cn-1H2n +CO22 +3H+3H22--
HEATHEAT
 CHCH44 +2H+2H22O = COO = CO22 +4H+4H22 –HEAT–HEAT
 COCO22 + H+ H22 = CO + H= CO + H220 - HEAT0 - HEAT

15. HOW OPERATING CONDIONSHOW OPERATING CONDIONS
ARE DECIDEDARE DECIDED
 AS PER LE CHATERLIERS PRINCIPLE THEAS PER LE CHATERLIERS PRINCIPLE THE
REACTION OF REFORMING REQUIRESREACTION OF REFORMING REQUIRES
 HIGH TEMERATUTRE CONDITIONSHIGH TEMERATUTRE CONDITIONS
 LOW PRESSURE CONDITIONSLOW PRESSURE CONDITIONS
 OPTIMUM PRESSURE IS SET ARROUNDOPTIMUM PRESSURE IS SET ARROUND
34KGCM34KGCM22
 PRESSURE BELOW THIS SUITS REFORMIGPRESSURE BELOW THIS SUITS REFORMIG
REACTION BUT THIS IS NOT SUITABLE FORREACTION BUT THIS IS NOT SUITABLE FOR
DOWNSREAM REACTIONSDOWNSREAM REACTIONS

16. CATALYST USED INCATALYST USED IN
REFORMINGREFORMING
 CATALYST USED IS NICKLECATALYST USED IS NICKLE
 IN VARIOUS REFORMING STEPS ONLYIN VARIOUS REFORMING STEPS ONLY
THE CONTENT OF NICKLE VARRIESTHE CONTENT OF NICKLE VARRIES
 BESIDES THIS BASE OF THE CATALYSTBESIDES THIS BASE OF THE CATALYST
ALSO VARRIESALSO VARRIES
 CONDENSATION OF STEAM IS TO BECONDENSATION OF STEAM IS TO BE
AVOIDED IN CATALYST BEDAVOIDED IN CATALYST BED
BECAUUSE IT MAY SPOIL THE ENTIREBECAUUSE IT MAY SPOIL THE ENTIRE
CATALYSTCATALYST

17. PRE REFORMERPRE REFORMER
 PRE REFORMER IS ISTALLED IN AMMONIAPRE REFORMER IS ISTALLED IN AMMONIA
EXPANSIONEXPANSION
 ITS PURPOSE IS TO REFORM HIGER HYDROCARBONITS PURPOSE IS TO REFORM HIGER HYDROCARBON
TO LOWER HYDROCARBONTO LOWER HYDROCARBON
 TO BE KEPT IN LINE WHEN NEPTHA IS BEING USEDTO BE KEPT IN LINE WHEN NEPTHA IS BEING USED
IN FEEDIN FEED
 WITHOUT PREREFORMER NEPTHA CAN NOT BEWITHOUT PREREFORMER NEPTHA CAN NOT BE
USED IN FEEDUSED IN FEED
 IT CAN BE KEPT IN LINE WITH NG ALSO BUT NOTIT CAN BE KEPT IN LINE WITH NG ALSO BUT NOT
WITH GREAT DEAL OF ADVANTAGEWITH GREAT DEAL OF ADVANTAGE
 ITS CATALYST IS ONE OF THE COSLIEST INITS CATALYST IS ONE OF THE COSLIEST IN
AMMONIA PLANTAMMONIA PLANT

18. PRE REFORMERPRE REFORMER
NI
NG+NEPTHA+STEAM
REFORMED GAS TO P R
490 ----510
440----470
PRE
REFORMER

19. PRIMARY REFORMERPRIMARY REFORMER
 IT IS THE MOST IMPORTANT STEP INIT IS THE MOST IMPORTANT STEP IN
THE REFORMING PROCESSTHE REFORMING PROCESS
 IT COSIST OF A FURNACEIT COSIST OF A FURNACE
 FURNACE IS SIDE FIREDFURNACE IS SIDE FIRED
 IT CONTAINS 288 TUBES AND 576IT CONTAINS 288 TUBES AND 576
BURNERSBURNERS
 CATALYST IS FILLED INSIDE THE TUBECATALYST IS FILLED INSIDE THE TUBE
 FIRING IS DONE ON BOTH THE SIDESFIRING IS DONE ON BOTH THE SIDES
OF THE TUBEOF THE TUBE

20. REFORMER FURNACEREFORMER FURNACE
NI
TUBES CH4 90%
CH4 11%
450---500
765

21. IMPORTANT PARAMETER OFIMPORTANT PARAMETER OF
PRIMARY REFORMERPRIMARY REFORMER
 FURNACE INSIDE PRESSURE SHOULD BEFURNACE INSIDE PRESSURE SHOULD BE
SLIHTLY BELOW ATMOSPHERIC PRESSURESLIHTLY BELOW ATMOSPHERIC PRESSURE
ARROND -5MMWCARROND -5MMWC
 TUBES SKIN TEMP SHOULD NOT EXCEEDTUBES SKIN TEMP SHOULD NOT EXCEED
905DEGREE CENTRIGADE OTHRWISE TUBE905DEGREE CENTRIGADE OTHRWISE TUBE
LIFE WOULD BE SHORTENEDLIFE WOULD BE SHORTENED
 S/C RATIO IS ONE OF THE MOST IMPS/C RATIO IS ONE OF THE MOST IMP
PARAMETE ITS KEPT ARROUND 3.3 LOWERPARAMETE ITS KEPT ARROUND 3.3 LOWER
S/C RATIO MAY RESULT IN CARBONS/C RATIO MAY RESULT IN CARBON
FORMATIONFORMATION

22. SECONDRY REFORMINGSECONDRY REFORMING
 AIMAIM
 TO COMLETE THE REMAININGTO COMLETE THE REMAINING
REFORMINGREFORMING
 TO INTRODUCE AIR SO THAT WE CANTO INTRODUCE AIR SO THAT WE CAN
GET N2 REQUIRED FOR THE AMMONIAGET N2 REQUIRED FOR THE AMMONIA
PRODUCTIONPRODUCTION

23. SECONDRY REFORMINGSECONDRY REFORMING
SECONDRY REFORMER
P REF O/L
AIR
S R O/L
1200
765
940
CH4 11%
CH4 .3%

24. WHAT HAPPENS IN SECONDRYWHAT HAPPENS IN SECONDRY
REFORMERREFORMER
 PRIMARY REFORMER OUTLET GASPRIMARY REFORMER OUTLET GAS
WHICH CONTAINS ABOUTWHICH CONTAINS ABOUT
11%METHANE AT ATEMP OF ABOUT11%METHANE AT ATEMP OF ABOUT
765DEGREE IS BROGHT IN CONTACT765DEGREE IS BROGHT IN CONTACT
WITH AIR AT A TEMP OF 575 DEGREEWITH AIR AT A TEMP OF 575 DEGREE
 FIRST REACTION IN SR IS EXOTHERMICFIRST REACTION IN SR IS EXOTHERMIC
REACTION IN WHICH APART OF GASREACTION IN WHICH APART OF GAS
BURNS WITH AIR O2 GETS CONSUMEDBURNS WITH AIR O2 GETS CONSUMED

25. WHAT HAPPENS IN SECONDRYWHAT HAPPENS IN SECONDRY
REFORMERREFORMER
 TEMERATURE OF GAS IN TOP PAERT OFTEMERATURE OF GAS IN TOP PAERT OF
REFORMER REACHES TO ARROUNDREFORMER REACHES TO ARROUND
1200 DEGREE1200 DEGREE
 THIS HEAT IS USED FOR FURTHERTHIS HEAT IS USED FOR FURTHER
REFORMINGREFORMING
 METHANE AT OUTLET OF SR BECOMESMETHANE AT OUTLET OF SR BECOMES
ABOUT .3%ABOUT .3%
 SR OUTLET TEMP BECOMES 940SR OUTLET TEMP BECOMES 940
DEGREEDEGREE

26. SHIFT REACTIONSHIFT REACTION
 AIMAIM
 GAS AT THE OUTLET OF SR CONTAINSGAS AT THE OUTLET OF SR CONTAINS
BOTH CO AND CO2BOTH CO AND CO2
 CO IS OF NO USECO IS OF NO USE
 CO2 IS REQUIRED FOR THECO2 IS REQUIRED FOR THE
PRODUCTION OF UREAPRODUCTION OF UREA
 IN SHIFT REACTORS ALL CO ISIN SHIFT REACTORS ALL CO IS
CONVERTED IN TO CO2CONVERTED IN TO CO2

27. SHIFT REACTIONSHIFT REACTION
 SHIFT REACTION IS TWO STEPSHIFT REACTION IS TWO STEP
PROCESSPROCESS
 FIRST STEP IS CARRIED OUT AT HIGHFIRST STEP IS CARRIED OUT AT HIGH
TEMP IT IS CALLED HT SHIFTTEMP IT IS CALLED HT SHIFT
REACTION TO INCREASE THE RATE OFREACTION TO INCREASE THE RATE OF
REACTIONREACTION
 SECOND STEP IS CARRIED OUT AT LOWSECOND STEP IS CARRIED OUT AT LOW
TEMP CALLED LT SHIFT REACTION ITTEMP CALLED LT SHIFT REACTION IT
IS TO ACHIVE HIGH EQULIBIRIUMIS TO ACHIVE HIGH EQULIBIRIUM
CONVERSIONCONVERSION

28. HT SHIFT CONVERTORHT SHIFT CONVERTOR
 CATALYST USED IRON OXIDECATALYST USED IRON OXIDE
 INLETTEMP 355 DEGREEINLETTEMP 355 DEGREE
 OUTLET TEMP 423DEGREEOUTLET TEMP 423DEGREE
 OUTLET CO 2.8%OUTLET CO 2.8%
 CO+HCO+H22O = COO = CO22 +H+H22

29. HT SHIFT CONVERTORHT SHIFT CONVERTOR
HT SHIFT
CATALYST
IRON OXIDE
SR OULET GAS
GAS TO LT
355
423
CO 2.8%
CO 12.77

30. LT CONVERTORLT CONVERTOR
 CATALEST USED MIANLY CUCATALEST USED MIANLY CU
 INLET TEMP 195 DEGREEINLET TEMP 195 DEGREE
 OUTLET 212 DEGREEOUTLET 212 DEGREE
 OUTLET CO .17%OUTLET CO .17%
 CO +HCO +H22O = COO = CO22 + H+ H22
 POISON FOR THE CATALYST AREPOISON FOR THE CATALYST ARE
 S AND CHLORIDES AND CHLORIDE

31. LT SHIFT CONVERTORLT SHIFT CONVERTOR
LT CONVERTOR
HT OUUTLET
LT OUTLET
CO .17%
CO 2.8%

32. CO2 REMOVALCO2 REMOVAL
 TWO MAIN PROCESS FOR THIS ARETWO MAIN PROCESS FOR THIS ARE
 BENFIELD PROCESS USED IN LINE 1BENFIELD PROCESS USED IN LINE 1
 GV PROCESS USED IN LINE 2GV PROCESS USED IN LINE 2
 GV PROCESS USED IN LINE 2 HAS SOMEGV PROCESS USED IN LINE 2 HAS SOME
ADVANTAGE OVER BENFIELD PROCESSADVANTAGE OVER BENFIELD PROCESS

33. GV PROCESSGV PROCESS
 AIMAIM
 TO REMOVE ALL CO2 FROM THETO REMOVE ALL CO2 FROM THE
PROCESS GAS BY ABSORBING IN HOTPROCESS GAS BY ABSORBING IN HOT
POTTASIUM CARBONATE SOLUTIONPOTTASIUM CARBONATE SOLUTION
AND THEN REGENERATING THEAND THEN REGENERATING THE
SOLUTIONSOLUTION
 CO2 PRODUCED IS SENT TO UREACO2 PRODUCED IS SENT TO UREA
PLANTPLANT

34. GV PROCESSGV PROCESS
 SOLUTION IS MADE OF POTTASSIUMSOLUTION IS MADE OF POTTASSIUM
CARBONATECARBONATE
 TWO ACTIVATORS USED ARETWO ACTIVATORS USED ARE
 GLYCENE AND DEAGLYCENE AND DEA
 COMPOSITIONCOMPOSITION
 KK22COCO33 27%27%
 GLYCENE 1.2%GLYCENE 1.2%
 DEA 1.0%DEA 1.0%
 VANADIUM .4%VANADIUM .4%

35. GV PROCESSGV PROCESS
 CHEMISTRY INVOLVEDCHEMISTRY INVOLVED
 ABSORBTION REACTIONABSORBTION REACTION
 KK22COCO33+H20+CO2 =2 KHCO+H20+CO2 =2 KHCO33
 REGENERATION REACTIONREGENERATION REACTION
 2KHCO2KHCO33 +HEAT = K+HEAT = K22COCO33 +H+H220+CO0+CO22

36. TWO STAGE REGENERATION & USE OF FLASH STEAM OF HP IN LPTWO STAGE REGENERATION & USE OF FLASH STEAM OF HP IN LP
REGENERATOR & REDUCTION IN LP STEAMREGENERATOR & REDUCTION IN LP STEAM
REDUCTION CO2 SLIP by 1000PPMREDUCTION CO2 SLIP by 1000PPM
IMPROVED HEAT RECOVERYIMPROVED HEAT RECOVERY

37. Heat loss to
atmosphere via
air cooler-12.68
Gcal/h

38. BLOCK DIGRAMBLOCK DIGRAM
 CO2 FREE GASCO2 FREE GAS
ABSORBER
GAS
SOLUTION
LOADED SOL
REGENERATOR
CO2
REGENERATED SOL
LOADED SOL
STEAM

39. METHNATIONMETHNATION
 AIMAIM
 TO CONVERT ALL CO AND COTO CONVERT ALL CO AND CO22 TOTO
METHANEMETHANE
 OUTLET GAS FROM COOUTLET GAS FROM CO22 REMOVALREMOVAL
AREA CONTAINS BOTH C0 AND C0AREA CONTAINS BOTH C0 AND C022
BOTH THESE GAS ARE NOT REQUIREDBOTH THESE GAS ARE NOT REQUIRED
AS THESE ARE POISON FOR THE SYNAS THESE ARE POISON FOR THE SYN
CATALYSTCATALYST

40. METHNATIONMETHNATION
 CATALYST USED NICKLECATALYST USED NICKLE
 C0 + HC0 + H22 = CH= CH44 + HEAT+ HEAT
 COCO22 +H+H22 =CH=CH44 + HEAT+ HEAT
 METHANE FORMED ACTS AS A INERTMETHANE FORMED ACTS AS A INERT
GAS IN SYN REACTION AND IT ISGAS IN SYN REACTION AND IT IS
REMOVED IN PURGE TAKEN OUT FROMREMOVED IN PURGE TAKEN OUT FROM
THE SYN LOOPTHE SYN LOOP

41. METHNATIONMETHNATION
METHNATOR
NICKLE
GAS FROM GV
CO .17% CO2 300 PPM
COANDCO2<1PPM
GAS TO COMP
290
306

42. COMP HOUSECOMP HOUSE
 COMP HOUSE CONTAINS THREE COMPCOMP HOUSE CONTAINS THREE COMP
 AIR COMPAIR COMP
 REFRIGRATION COMPREFRIGRATION COMP
 SYNTHESIS COMPSYNTHESIS COMP

43. AIR COMPAIR COMP
 AIMAIM
 AIR COMPRESSOR COMPRESSES AIR UPAIR COMPRESSOR COMPRESSES AIR UP
TO 34KGCM2 PRESSURETO 34KGCM2 PRESSURE
 AIR IS USED IN SECONDRY REFORMERAIR IS USED IN SECONDRY REFORMER
 H2/N2 RATIO DETERMINES FLOW OFH2/N2 RATIO DETERMINES FLOW OF
AIR TO SECONDRY REFORMERAIR TO SECONDRY REFORMER

44. AIR COMPAIR COMP
AIR COMP
AIR TO SECONDRY REFORMER
34KG /CM2 170ATMOS AIR

45. REFRIGRATION COMPRESSORREFRIGRATION COMPRESSOR
 AIMAIM
 IT IS USED TO COMPRESS AMMONIAIT IS USED TO COMPRESS AMMONIA
WHICH IS USED AS A REFRIGRENT INWHICH IS USED AS A REFRIGRENT IN
SYNTHESIS LOOPSYNTHESIS LOOP
 REFIGRATION IS DONE AT THREEREFIGRATION IS DONE AT THREE
PRESSURE LEVELPRESSURE LEVEL
 ITS FINAL DISCHARGE PRESSURE ISITS FINAL DISCHARGE PRESSURE IS
14KG CM214KG CM2

46. SYNTHESIS COMPSYNTHESIS COMP
 AIMAIM
 AMMONIA SYNTHESIS REACTION ISAMMONIA SYNTHESIS REACTION IS
CARRIED OUT AT HIGH PRESSURECARRIED OUT AT HIGH PRESSURE
CONDITIONS AT ABOUT 180KGCM2CONDITIONS AT ABOUT 180KGCM2
 SYN COMP IS USED TO COMPRESS GASSYN COMP IS USED TO COMPRESS GAS
UP TO THAT PRESSUREUP TO THAT PRESSURE

47. Syn compressorSyn compressor
Gas to comp
Gas to loop
Gas from loop
Gas to conv26kg/cm2
175
172kg/cm2
180kg/cm2

48. AMMONIA SYNTHESISAMMONIA SYNTHESIS
 AIMAIM
 TO PRODUCE AMMONIA WITH THETO PRODUCE AMMONIA WITH THE
HELP OF SYN GAS COMING FROMHELP OF SYN GAS COMING FROM
METHNATORMETHNATOR
 SYN GAS CONTAINS MAINLY HSYN GAS CONTAINS MAINLY H22 AND NAND N22

49. AMMONIA SYN REACTIONAMMONIA SYN REACTION
 3H3H22 +N+N22 = 2NH= 2NH33 +HEAT+HEAT
 CATALYST USED IRONCATALYST USED IRON
 REACTION CONDITIONREACTION CONDITION
 HIGH PRESSURE AND LOW TEMPHIGH PRESSURE AND LOW TEMP

50. AMMONA SYN REACTIONAMMONA SYN REACTION
 AMMONIA SYN REACTION IS A REVERSIBILEAMMONIA SYN REACTION IS A REVERSIBILE
REACTION AND EQULIBIRIUM CONDITION ISREACTION AND EQULIBIRIUM CONDITION IS
DETERMINED BY TEMP AND PRESSUREDETERMINED BY TEMP AND PRESSURE
CONDITIONSCONDITIONS
 IN ONE PASS THROUGH THE CONVERTORIN ONE PASS THROUGH THE CONVERTOR
ONLY 30% OF THE REACTANTS GETSONLY 30% OF THE REACTANTS GETS
CONVERTED TO THE PRODUCT SOCONVERTED TO THE PRODUCT SO
REMAINING GAS KEEPS ON CIRCULATINGREMAINING GAS KEEPS ON CIRCULATING

51. BLOCK DIGRAMBLOCK DIGRAM
GAS TO CONV
OUT LET GAS
H2 AND N2
H2 N2 AND NH3

53. BLOCK DIGRAM OF SYNBLOCK DIGRAM OF SYN
SECTIONSECTION
AMM CONVERTOR BFW HEATER
GAS GAS EX WATER COOLER GAS GAS EX
PRI CHIL SEC CHILL AMM SEP LET DOWNVESSLE
LOOP BOILER
STEAM
PURGE GAS
AMM TO UREA
TO
STORAGE
SYN GAS

55. What is purgeWhat is purge
 AS AMMONIA SYN REACTION IS NOTAS AMMONIA SYN REACTION IS NOT
COMPLETED IN ONE STEP AND GAS IS KEPTCOMPLETED IN ONE STEP AND GAS IS KEPT
ON CIRCULATING INERTS BUILDS UP IN THEON CIRCULATING INERTS BUILDS UP IN THE
LOOPLOOP
 INERT MEANS CH4, Ar NH3 AT INLET OFINERT MEANS CH4, Ar NH3 AT INLET OF
CONV THEIR CONCENTRATION SHALL NOTCONV THEIR CONCENTRATION SHALL NOT
INCREASE BEYOND 14%INCREASE BEYOND 14%
 SO A SMALL AMMOUNT OF GAS ISSO A SMALL AMMOUNT OF GAS IS
CONTTIOUSLY WITHDRAWN FROM THECONTTIOUSLY WITHDRAWN FROM THE
LOOP THIS STREAM OF THE GAS IS CALLEDLOOP THIS STREAM OF THE GAS IS CALLED
PUGE GASPUGE GAS

56. PURGE GAS RECOVERYPURGE GAS RECOVERY
 PURGE GAS CONTAINS HPURGE GAS CONTAINS H22, CH, CH44 ANDAND
AMMONIAAMMONIA
 AMMONIA IS RECOVERED BYAMMONIA IS RECOVERED BY
WASHING THE GAS WITH WATER ANDWASHING THE GAS WITH WATER AND
REMAINING GAS WHICH CONTAINS CHREMAINING GAS WHICH CONTAINS CH44
AND HAND H22 IS USED IN REFORMER FIRINGIS USED IN REFORMER FIRING
SYSTEMSYSTEM

57. PURGE GAS RECOVERYPURGE GAS RECOVERY
ABSORBER REGENERATIONR
PUURGE
WATER
STEAM
GAS TO REF
LOADED SOL
AM TO STORAGE

58. Installation of Plate type Combustion airInstallation of Plate type Combustion air
preheaterpreheater
 Facilitate reduction in reformer stack temperature toFacilitate reduction in reformer stack temperature to
125125°C°C
 Energy saving: 0.055 Gcal /MT NH3Energy saving: 0.055 Gcal /MT NH3
 Energy saving due toEnergy saving due to
 a) NG saving due to increase in combustion aira) NG saving due to increase in combustion air
temperaturetemperature
 B) Reduction in steam consumption in ID FanB) Reduction in steam consumption in ID Fan

59. Conversion of Benfield process to GVConversion of Benfield process to GV
processprocess
 To increase capacity and improve energyTo increase capacity and improve energy
effciencyeffciency
 GV 2 stage process has a lower specificGV 2 stage process has a lower specific
regeneration heat requirement and henceregeneration heat requirement and hence
reduction in low pressure steam consumption byreduction in low pressure steam consumption by
utilizing flash steam of HP regenerator &utilizing flash steam of HP regenerator &
utilization heat by LP steam reboiler instead ofutilization heat by LP steam reboiler instead of
loosing to atmosphere through air coolerloosing to atmosphere through air cooler
 Energy savings: 0.18 Gcal/MT NH3Energy savings: 0.18 Gcal/MT NH3
 Existing Amm-II is based on GV ProcessExisting Amm-II is based on GV Process

60. New equipment in conversion from Benfield to GVNew equipment in conversion from Benfield to GV
sectionsection
 Separator OH 2Separator OH 2ndnd
regenerator (B-1307)regenerator (B-1307)
 LP steam boiler (E-1301)LP steam boiler (E-1301)
 DMW pre-heater (E-1305 A/B)DMW pre-heater (E-1305 A/B)
 Condenser OH 2Condenser OH 2ndnd
regenerator (E-1309)regenerator (E-1309)
 22ndnd
Regenerator (F-1303)Regenerator (F-1303)
 Steam Ejector (X-1301)Steam Ejector (X-1301)
 Aeration Injection tank (T-1305)Aeration Injection tank (T-1305)
 Sealing water heater (E-1315)Sealing water heater (E-1315)
 Cooler for Aeration tank (E-1324)Cooler for Aeration tank (E-1324)
 Activated carbon filter and 2Activated carbon filter and 2ndnd
Mechanical filterMechanical filter

61. New machinery in conversion from Benfield to GVNew machinery in conversion from Benfield to GV
sectionsection
 CO2 blower (K-1301)CO2 blower (K-1301)
 Semi-lean solution pump (P-1301D)Semi-lean solution pump (P-1301D)
 Lean solution pump (P-1302 A/B)Lean solution pump (P-1302 A/B)
 22ndnd
condensate pump (P-1308 A/B)condensate pump (P-1308 A/B)
 Aeration Injection pump (P-1309 A/B)Aeration Injection pump (P-1309 A/B)
 Sealing water pump (P-1310 A/B)Sealing water pump (P-1310 A/B)

62. Modifications in 1Modifications in 1stst
regeneratorregenerator
 New take off trays are installed below bed 2New take off trays are installed below bed 2
and above bed 3and above bed 3
 New liquid re-distributors above bed 1 and 3New liquid re-distributors above bed 1 and 3
 Bed limiters over beds 1 and 3Bed limiters over beds 1 and 3
 11stst
bed height reduced by 2195 mmbed height reduced by 2195 mm
 DemisterDemister
 New nozzles and instrumentation for newNew nozzles and instrumentation for new
take-off traystake-off trays

63. Modification in CO2 absorberModification in CO2 absorber
 Liquid distributor over Bed 2 and 4Liquid distributor over Bed 2 and 4
 Liquid redistributor over beds 1,2,3 & 4Liquid redistributor over beds 1,2,3 & 4
 Gas distributor under bed 1Gas distributor under bed 1
 Packing : Bed 1: IMTP 50 Bed 4: IMTP25Packing : Bed 1: IMTP 50 Bed 4: IMTP25

64. Installation of S-50 converterInstallation of S-50 converter
 To increase the energy efficiency of the ammoniaTo increase the energy efficiency of the ammonia
synthesis loop, an S-50 converter R-1502 is installedsynthesis loop, an S-50 converter R-1502 is installed
downstream of the existing converter.downstream of the existing converter.
 The increase in ammonia concentration exit the newThe increase in ammonia concentration exit the new
converter results in a decrease in loop pressure and aconverter results in a decrease in loop pressure and a
lower circulation rate, which gives savings on thelower circulation rate, which gives savings on the
synthesis gas compressor and the refrigerationsynthesis gas compressor and the refrigeration
compressor.compressor.
 Energy saving: 0.18 Gcal/MT NH3Energy saving: 0.18 Gcal/MT NH3

65. Advantages of addition of S-50 LoopAdvantages of addition of S-50 Loop
 Ammonia concentration at the outlet of S-50 =Ammonia concentration at the outlet of S-50 =
24.35% as compared to 20.02% in S-20024.35% as compared to 20.02% in S-200
 Higher conversion 35.5 % as compared to 28.3% in S-200Higher conversion 35.5 % as compared to 28.3% in S-200
 Lower circulation rate as compared to S-200 for sameLower circulation rate as compared to S-200 for same
loadload
 Higher steam generation 82 T/hr as compared to 70 T/hr in S-Higher steam generation 82 T/hr as compared to 70 T/hr in S-
200200
 Lower synthesis loop pressureLower synthesis loop pressure
 Lower compressor power due to less circulation and lowLower compressor power due to less circulation and low
pressurepressure
 Possible to achieve higher plant load with same equipmentsPossible to achieve higher plant load with same equipments

66. S-50 Integration in synthesis loop

68. Parallel Air compressorParallel Air compressor
 Addition of Parallel air compressorAddition of Parallel air compressor
(reciprocating type) to meet the additional(reciprocating type) to meet the additional
process air requirementprocess air requirement
 Process air from Existing PAC: 59152Process air from Existing PAC: 59152
Nm3/hrNm3/hr
 Process air from New Compressor: 6030Process air from New Compressor: 6030
Nm3/hrNm3/hr
 Total air requirement for 1750 MTPDTotal air requirement for 1750 MTPD
ammonia as per PFD: 65181 Nm3/hrammonia as per PFD: 65181 Nm3/hr

69. Ammonia-II CEP: Process airAmmonia-II CEP: Process air
 As per PFD of Ammonia-II CEP, the totalAs per PFD of Ammonia-II CEP, the total
requirement of process air from PAC ofrequirement of process air from PAC of
Ammonia-II shall be 75683 Nm3/hr withAmmonia-II shall be 75683 Nm3/hr with
distribution as follows:distribution as follows:
 Process air for Ammonia-II CEP : 69234Process air for Ammonia-II CEP : 69234
Nm3/hrNm3/hr
 Instrument air : 3924 Nm3/hrInstrument air : 3924 Nm3/hr
 Export to Ammonia-I : 2525 Nm3/hrExport to Ammonia-I : 2525 Nm3/hr
6969

70. Ammonia-II CEP: HTAS report & OEM reviewAmmonia-II CEP: HTAS report & OEM review
 The capacity of existing PAC in Ammonia-II is : Normal:The capacity of existing PAC in Ammonia-II is : Normal:
59275 Nm³/h , Rated : 64900 Nm³/h59275 Nm³/h , Rated : 64900 Nm³/h
 Based on overall performance curve of PAC, HTAS hasBased on overall performance curve of PAC, HTAS has
confirmed that the desired load shall remain within theconfirmed that the desired load shall remain within the
operating range of the compressor.operating range of the compressor.
 OEM of PAC of Ammonia-II has confirmed that it shouldOEM of PAC of Ammonia-II has confirmed that it should
be possible to operate the machine with 75372 Nm³/hbe possible to operate the machine with 75372 Nm³/h
without modifications.without modifications.
 It was practically observed that the machine is in positionIt was practically observed that the machine is in position
to deliver the desired load with no limitation on driverto deliver the desired load with no limitation on driver
side.side.
7070

71. LINE1 AND LINE2 DIFFERENCELINE1 AND LINE2 DIFFERENCE
 LINE 1 DOES NOT HAVE MIXED FEEDLINE 1 DOES NOT HAVE MIXED FEED
CAPABILITY ONLY NG CAN BE USEDCAPABILITY ONLY NG CAN BE USED
AS FEEDAS FEED
 IN LINE1 AIR COMP IS RUN BY STEAMIN LINE1 AIR COMP IS RUN BY STEAM
TURBINE IN LINE 2 GT IS USED FORTURBINE IN LINE 2 GT IS USED FOR
RUNNING AIR COMPRUNNING AIR COMP

72. LINE1 AND LINE2 DIFFERENCELINE1 AND LINE2 DIFFERENCE
 IN LINE 1 STRIPPING OF CONDENSATEIN LINE 1 STRIPPING OF CONDENSATE
IS DONE BY LOW PREESURE STEAMIS DONE BY LOW PREESURE STEAM
AND ALL THE STEAM IS VENTED TOAND ALL THE STEAM IS VENTED TO
ATMOSPHEREATMOSPHERE
 IN LINE 2 STRIIPING IS DONE BY MPIN LINE 2 STRIIPING IS DONE BY MP
STEAM AND STEAM IS REUSED INSTEAM AND STEAM IS REUSED IN
REFORMER THUS SAVING THE ENERGYREFORMER THUS SAVING THE ENERGY

73. LINE1 AND LINE2 DIFFERENCELINE1 AND LINE2 DIFFERENCE
 IN LINE 1 BENFIELD PROCESS IS USEDIN LINE 1 BENFIELD PROCESS IS USED
FOR CO2 STRIPPINGFOR CO2 STRIPPING
 IN LINE 2 GV PROCESS IS USED FORIN LINE 2 GV PROCESS IS USED FOR
CO2 REMOVALCO2 REMOVAL
 LINE 1 DOES NOT HAVE PRELINE 1 DOES NOT HAVE PRE
REFORMERREFORMER

74. LINE1 AND LINE2 DIFFERENCELINE1 AND LINE2 DIFFERENCE
 IN LINE 1 BENFIELD PROCESS IS USEDIN LINE 1 BENFIELD PROCESS IS USED
FOR CO2 STRIPPINGFOR CO2 STRIPPING
 IN LINE 2 GV PROCESS IS USED FORIN LINE 2 GV PROCESS IS USED FOR
CO2 REMOVALCO2 REMOVAL
 LINE 1 DOES NOT HAVE PRELINE 1 DOES NOT HAVE PRE
REFORMERREFORMER