Ammonia plant

SIMPLE WAY TO SIMPLE WAY TO UNDERSTAND AMMONIA UNDERSTAND AMMONIA

PLANTPLANT

BYBY

PREM BABOOPREM BABOO

SR. MANAGER(PROD)SR. MANAGER(PROD)

NATIONAL FERTILIZERS LTD,VIJAIPUR, INDIANATIONAL FERTILIZERS LTD,VIJAIPUR, INDIA

SIMPLE WAY TO UNDERSTAND SIMPLE 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

INGREDIENT FOR AMMONIAINGREDIENT FOR AMMONIA

TO PRODUCE AMMONIA WE REQUIRE TO PRODUCE AMMONIA WE REQUIRE HH22 AND N AND N22

HH22 WE GET FROM NG AND WATER WE GET FROM NG AND WATER

NN22 WE GET FROM AIR WE GET FROM AIR

NG CONTAINS ABOUT 92%CHNG CONTAINS ABOUT 92%CH44

NEPTHA CONTAINS HIGHER NEPTHA CONTAINS HIGHER HYDROCAREBONHYDROCAREBON

BLOCK DIGRAM OF AMOONIA BLOCK DIGRAM OF AMOONIA PLANTPLANT

DESULPHERISATION REFORMING

SHIFT REACTION CO2 REMOVAL AREA

SYNTHESISCOMP HOUSE

CO2 TO UREA

AMM TO UREA

AND METHNATION

DESULPHERISATIONDESULPHERISATION

AIMAIM TO REMOVE ALL SULPHERTO REMOVE ALL SULPHER

COMING WITH NG AND NEPTHA COMING WITH NG AND NEPTHA SULPHER IS POISIONOUS FOR THE SULPHER IS POISIONOUS FOR THE

DOWNSTREAM CATALAYSTDOWNSTREAM CATALAYST IT CONSISTS OF TWO STEPSIT CONSISTS OF TWO STEPS

HYDROGENATIONHYDROGENATION

IN THIS VESSLE NG AND NEPTHA ARE IN THIS VESSLE NG AND NEPTHA ARE BROUGHT IN CONTACT WITH BROUGHT IN CONTACT WITH HYDROGEN SO THAT ORGANIC HYDROGEN SO THAT ORGANIC SULPHER GETS CONVERTED INTO SULPHER GETS CONVERTED INTO INORGANIC SULPHER WHICH IS INORGANIC SULPHER WHICH IS SUBSEQUENTLY REMOVED IN ZNO SUBSEQUENTLY REMOVED IN ZNO ABSORBERABSORBER

CATALYST NIMO –FOR NGCATALYST NIMO –FOR NG COMO -FOR NAPHTHACOMO -FOR NAPHTHA

HYDRODE-SULPHERISATIONHYDRODE-SULPHERISATION

ALL ORGANIC SULPHER GETS ALL ORGANIC SULPHER GETS CONVERTED IN H2SCONVERTED IN H2S

HDS

NIMO

NG

H2

OUTLET

RSH +H2 =RH +H2S

R1SSR2 +H2 = R1H +R2H +H2S

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 + H22O O SULPHER AT THE OUTLET OF THESE VESSLE ARE SULPHER AT THE OUTLET OF THESE VESSLE ARE

LESS THAN .01PPMLESS THAN .01PPM INCREASING SULPHER CONTENT GIVE THE INCREASING SULPHER CONTENT GIVE THE

INDICATION THAT BEDS ARE GETTING EXHUSTED INDICATION THAT BEDS ARE GETTING EXHUSTED AND THEY REQUIRE CHANGE AND THEY REQUIRE CHANGE

FIRST BED CAN BE BYPASSED AND CATALYST CAN FIRST BED CAN BE BYPASSED AND CATALYST CAN BE CHANGED ON LINE A SPECIAL BED OF Copper BE CHANGED ON LINE A SPECIAL BED OF Copper BASEDCATALYST IS INSTALLED AT THE BOTTOM OF BASEDCATALYST IS INSTALLED AT THE BOTTOM OF THE FIRST BED TO ADSORB ANY ORGANIC SULPHER THE FIRST BED TO ADSORB ANY ORGANIC SULPHER IF IT SLIPS FROM HYDROGEATION BEDIF IT SLIPS FROM HYDROGEATION BED

DESULPHERISATIONDESULPHERISATION

ZnO +HZnO +H22S = ZnS +HS = ZnS +H22

ZnO ZnO

TO REFORMER

FROM HDS

REFORMINGREFORMING

AIM AIM TO REFORM NG AND NEPTHA IN TO HTO REFORM NG AND NEPTHA IN TO H22

CO AND COCO AND CO22 REFORMING IS DONE WITH REFORMING IS DONE WITH

THE HELP OF STEAM THATIS WHY IT IS THE HELP OF STEAM THATIS WHY IT IS CALLED STEAM REFORMING IT CALLED STEAM REFORMING IT CONSIST OF THREE STEPSCONSIST OF THREE STEPS

STEPS OF REFORMINGSTEPS OF REFORMING

PREREFORMERPREREFORMER

PRIMARY REFORMERPRIMARY REFORMER

SECONDRY REFORMERSECONDRY REFORMER

CONDITION OF REFORMING CONDITION OF REFORMING

REFORMING IS AN ENDOTHERMIC REACTIONREFORMING IS AN ENDOTHERMIC REACTION IT MEANS THAT HEAT WILL HAVE TO BE IT MEANS THAT HEAT WILL HAVE TO BE

SUPPLIED TO MOVE THE REACTION IN SUPPLIED TO MOVE THE REACTION IN FORWARD DIRECTION FORWARD DIRECTION

MAJOR PORTION OF REFORMING IS DONE IN MAJOR PORTION OF REFORMING IS DONE IN PRIMARY REFORMER THIS REACTION IS PRIMARY REFORMER THIS REACTION IS CARRIED OUT IN A FURNACE OPERATING CARRIED OUT IN A FURNACE OPERATING CONDITIONS ARE VERY INTENCECONDITIONS ARE VERY INTENCE

REACTIONS OF REFORMING REACTIONS 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

HOW OPERATING CONDIONS HOW OPERATING CONDIONS ARE DECIDEDARE DECIDED

AS PER LE CHATERLIERS PRINCIPLE THE AS PER LE CHATERLIERS PRINCIPLE THE REACTION OF REFORMING REQUIRES REACTION OF REFORMING REQUIRES

HIGH TEMERATUTRE CONDITIONSHIGH TEMERATUTRE CONDITIONS LOW PRESSURE CONDITIONS LOW PRESSURE CONDITIONS OPTIMUM PRESSURE IS SET ARROUND 34KG\OPTIMUM PRESSURE IS SET ARROUND 34KG\

CMCM22

PRESSURE BELOW THIS SUITS REFORMIG PRESSURE BELOW THIS SUITS REFORMIG REACTION BUT THIS IS NOT SUITABLE FOR REACTION BUT THIS IS NOT SUITABLE FOR DOWNSREAM REACTIONSDOWNSREAM REACTIONS

CATALYST USED IN CATALYST USED IN REFORMINGREFORMING

CATALYST USED IS NICKLECATALYST USED IS NICKLE IN VARIOUS REFORMING STEPS ONLY IN VARIOUS REFORMING STEPS ONLY

THE CONTENT OF NICKLE VARRIES THE CONTENT OF NICKLE VARRIES BESIDES THIS BASE OF THE CATALYST BESIDES THIS BASE OF THE CATALYST

ALSO VARRIESALSO VARRIES CONDENSATION OF STEAM IS TO BE CONDENSATION OF STEAM IS TO BE

AVOIDED IN CATALYST BED AVOIDED IN CATALYST BED BECAUUSE IT MAY SPOIL THE ENTIRE BECAUUSE IT MAY SPOIL THE ENTIRE CATALYST CATALYST

PRE REFORMERPRE REFORMER PRE REFORMER IS ISTALLED IN AMMONIA PRE REFORMER IS ISTALLED IN AMMONIA

EXPANSION EXPANSION ITS PURPOSE IS TO REFORM HIGER HYDROCARBON ITS PURPOSE IS TO REFORM HIGER HYDROCARBON

TO LOWER HYDROCARBONTO LOWER HYDROCARBON TO BE KEPT IN LINE WHEN NEPTHA IS BEING USED TO BE KEPT IN LINE WHEN NEPTHA IS BEING USED

IN FEED IN FEED WITHOUT PREREFORMER NEPTHA CAN NOT BE WITHOUT PREREFORMER NEPTHA CAN NOT BE

USED IN FEEDUSED IN FEED IT CAN BE KEPT IN LINE WITH NG ALSO BUT NOT IT 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 IN ITS CATALYST IS ONE OF THE COSLIEST IN

AMMONIA PLANTAMMONIA PLANT

PRE REFORMERPRE REFORMER

NI

NG+NEPTHA+STEAM

REFORMED GAS TO P R

490 ----510

440----470

PREREFORMER

PRIMARY REFORMERPRIMARY REFORMER

IT IS THE MOST IMPORTANT STEP IN IT IS THE MOST IMPORTANT STEP IN THE REFORMING PROCESSTHE REFORMING PROCESS

IT COSIST OF A FURNACE IT COSIST OF A FURNACE FURNACE IS SIDE FIREDFURNACE IS SIDE FIRED IT CONTAINS 288 TUBES AND 576 IT CONTAINS 288 TUBES AND 576

BURNERSBURNERS CATALYST IS FILLED INSIDE THE TUBECATALYST IS FILLED INSIDE THE TUBE FIRING IS DONE ON BOTH THE SIDES OF FIRING IS DONE ON BOTH THE SIDES OF

THE TUBETHE TUBE

REFORMER FURNACEREFORMER FURNACE

NI

TUBES CH4 90%

CH4 11%

450---500

765

IMPORTANT PARAMETER OF IMPORTANT PARAMETER OF PRIMARY REFORMERPRIMARY REFORMER

FURNACE INSIDE PRESSURE SHOULD BE FURNACE INSIDE PRESSURE SHOULD BE SLIHTLY BELOW ATMOSPHERIC PRESSURE SLIHTLY BELOW ATMOSPHERIC PRESSURE ARROND -5MMWCARROND -5MMWC

TUBES SKIN TEMP SHOULD NOT EXCEED TUBES SKIN TEMP SHOULD NOT EXCEED 905DEGREE CENTRIGADE OTHRWISE TUBE 905DEGREE CENTRIGADE OTHRWISE TUBE LIFE WOULD BE SHORTENEDLIFE WOULD BE SHORTENED

S/C RATIO IS ONE OF THE MOST IMP S/C RATIO IS ONE OF THE MOST IMP PARAMETE ITS KEPT ARROUND 3.3 LOWER PARAMETE ITS KEPT ARROUND 3.3 LOWER S/C RATIO MAY RESULT IN CARBON S/C RATIO MAY RESULT IN CARBON FORMATIONFORMATION

SECONDRY REFORMINGSECONDRY REFORMING

AIMAIM TO COMLETE THE REMAINING TO COMLETE THE REMAINING

REFORMINGREFORMING TO INTRODUCE AIR SO THAT WE CAN TO INTRODUCE AIR SO THAT WE CAN

GET N2 REQUIRED FOR THE AMMONIA GET N2 REQUIRED FOR THE AMMONIA PRODUCTIONPRODUCTION

SECONDRY REFORMINGSECONDRY REFORMING

SECONDRY REFORMER

P REF O/L

AIR

S R O/L

1200

765

940

CH4 11%

CH4 .3%

WHAT HAPPENS IN SECONDRY WHAT HAPPENS IN SECONDRY REFORMERREFORMER

PRIMARY REFORMER OUTLET GAS PRIMARY REFORMER OUTLET GAS WHICH CONTAINS ABOUT WHICH CONTAINS ABOUT 11%METHANE AT ATEMP OF ABOUT 11%METHANE AT ATEMP OF ABOUT 765DEGREE IS BROGHT IN CONTACT 765DEGREE IS BROGHT IN CONTACT WITH AIR AT A TEMP OF 575 DEGREEWITH AIR AT A TEMP OF 575 DEGREE

FIRST REACTION IN SR IS EXOTHERMIC FIRST REACTION IN SR IS EXOTHERMIC REACTION IN WHICH APART OF GAS REACTION IN WHICH APART OF GAS BURNS WITH AIR O2 GETS CONSUMED BURNS WITH AIR O2 GETS CONSUMED

WHAT HAPPENS IN SECONDRY WHAT HAPPENS IN SECONDRY REFORMERREFORMER

TEMERATURE OF GAS IN TOP PAERT OF TEMERATURE OF GAS IN TOP PAERT OF REFORMER REACHES TO ARROUND REFORMER REACHES TO ARROUND 1200 DEGREE1200 DEGREE

THIS HEAT IS USED FOR FURTHER THIS HEAT IS USED FOR FURTHER REFORMING REFORMING

METHANE AT OUTLET OF SR BECOMES METHANE AT OUTLET OF SR BECOMES ABOUT .3%ABOUT .3%

SR OUTLET TEMP BECOMES 940 SR OUTLET TEMP BECOMES 940 DEGREEDEGREE

SHIFT REACTIONSHIFT REACTION

AIMAIM GAS AT THE OUTLET OF SR CONTAINS GAS 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 THE CO2 IS REQUIRED FOR THE

PRODUCTION OF UREAPRODUCTION OF UREA IN SHIFT REACTORS ALL CO IS IN SHIFT REACTORS ALL CO IS

CONVERTED IN TO CO2CONVERTED IN TO CO2

SHIFT REACTIONSHIFT REACTION

SHIFT REACTION IS TWO STEP PROCESSSHIFT REACTION IS TWO STEP PROCESS FIRST STEP IS CARRIED OUT AT HIGH FIRST STEP IS CARRIED OUT AT HIGH

TEMP IT IS CALLED HT SHIFT TEMP IT IS CALLED HT SHIFT REACTION TO INCREASE THE RATE OF REACTION TO INCREASE THE RATE OF REACTIONREACTION

SECOND STEP IS CARRIED OUT AT LOW SECOND STEP IS CARRIED OUT AT LOW TEMP CALLED LT SHIFT REACTION IT TEMP CALLED LT SHIFT REACTION IT IS TO ACHIVE HIGH EQULIBIRIUM IS TO ACHIVE HIGH EQULIBIRIUM CONVERSIONCONVERSION

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

HT SHIFT CONVERTORHT SHIFT CONVERTOR

HT SHIFT

CATALYST

IRON OXIDE

SR OULET GAS

GAS TO LT

355

423CO 2.8%

CO 12.77

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

LT SHIFT CONVERTORLT SHIFT CONVERTOR

LT CONVERTOR

HT OUUTLET

LT OUTLET

CO .17%

CO 2.8%

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 SOME GV PROCESS USED IN LINE 2 HAS SOME

ADVANTAGE OVER BENFIELD PROCESSADVANTAGE OVER BENFIELD PROCESS

GV PROCESSGV PROCESS

AIM AIM TO REMOVE ALL CO2 FROM THE TO REMOVE ALL CO2 FROM THE

PROCESS GAS BY ABSORBING IN HOT PROCESS GAS BY ABSORBING IN HOT POTTASIUM CARBONATE SOLUTION POTTASIUM CARBONATE SOLUTION AND THEN REGENERATING THE AND THEN REGENERATING THE SOLUTION SOLUTION

CO2 PRODUCED IS SENT TO UREA CO2 PRODUCED IS SENT TO UREA PLANTPLANT


SOLUTION IS MADE OF POTTASSIUM SOLUTION IS MADE OF POTTASSIUM CARBONATECARBONATE

TWO ACTIVATORS USED ARE TWO 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%


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

TWO STAGE REGENERATION & USE OF FLASH STEAM OF HP IN LP TWO STAGE REGENERATION & USE OF FLASH STEAM OF HP IN LP REGENERATOR & REDUCTION IN LP STEAM REGENERATOR & REDUCTION IN LP STEAM

REDUCTION CO2 SLIP by 1000PPMREDUCTION CO2 SLIP by 1000PPMIMPROVED HEAT RECOVERYIMPROVED HEAT RECOVERY

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

BLOCK DIGRAMBLOCK DIGRAM

CO2 FREE GASCO2 FREE GAS

ABSORBER

GAS

SOLUTION

LOADED SOL

REGENERATOR

CO2

REGENERATED SOL

LOADED SOL

STEAM

METHNATIONMETHNATION

AIM AIM TO CONVERT ALL CO AND COTO CONVERT ALL CO AND CO22 TO TO

METHANEMETHANE

OUTLET GAS FROM COOUTLET GAS FROM CO22 REMOVAL REMOVAL AREA CONTAINS BOTH C0 AND C0AREA CONTAINS BOTH C0 AND C022 BOTH THESE GAS ARE NOT REQUIRED BOTH THESE GAS ARE NOT REQUIRED AS THESE ARE POISON FOR THE SYN AS THESE ARE POISON FOR THE SYN CATALYSTCATALYST


CATALYST USED NICKLECATALYST USED NICKLE C0 + HC0 + H22 = CH = CH44 + HEAT + HEAT

COCO22 +H +H22 =CH =CH44 + HEAT + HEAT METHANE FORMED ACTS AS A INERT METHANE FORMED ACTS AS A INERT

GAS IN SYN REACTION AND IT IS GAS IN SYN REACTION AND IT IS REMOVED IN PURGE TAKEN OUT FROM REMOVED IN PURGE TAKEN OUT FROM THE SYN LOOPTHE SYN LOOP


METHNATORNICKLE

GAS FROM GV

CO .17% CO2 300 PPM

COANDCO2<1PPM

GAS TO COMP

290

306

COMP HOUSECOMP HOUSE

COMP HOUSE CONTAINS THREE COMPCOMP HOUSE CONTAINS THREE COMP AIR COMPAIR COMP

REFRIGRATION COMPREFRIGRATION COMP

SYNTHESIS COMPSYNTHESIS COMP

AIR COMPAIR COMP

AIMAIM AIR COMPRESSOR COMPRESSES AIR UP AIR COMPRESSOR COMPRESSES AIR UP

TO 34KG\CM2 PRESSURETO 34KG\CM2 PRESSURE AIR IS USED IN SECONDRY REFORMERAIR IS USED IN SECONDRY REFORMER H2/N2 RATIO DETERMINES FLOW OF H2/N2 RATIO DETERMINES FLOW OF

AIR TO SECONDRY REFORMERAIR TO SECONDRY REFORMER

AIR COMPAIR COMP

AIR COMP

AIR TO SECONDRY REFORMER

34KG /CM2 170ATMOS AIR

REFRIGRATION COMPRESSORREFRIGRATION COMPRESSOR

AIMAIM IT IS USED TO COMPRESS AMMONIA IT IS USED TO COMPRESS AMMONIA

WHICH IS USED AS A REFRIGRENT IN WHICH IS USED AS A REFRIGRENT IN SYNTHESIS LOOPSYNTHESIS LOOP

REFIGRATION IS DONE AT THREE REFIGRATION IS DONE AT THREE PRESSURE LEVELPRESSURE LEVEL

ITS FINAL DISCHARGE PRESSURE IS ITS FINAL DISCHARGE PRESSURE IS 14KG \CM214KG \CM2

SYNTHESIS COMPSYNTHESIS COMP

AIMAIM AMMONIA SYNTHESIS REACTION IS AMMONIA SYNTHESIS REACTION IS

CARRIED OUT AT HIGH PRESSURE CARRIED OUT AT HIGH PRESSURE CONDITIONS AT ABOUT 180KG\CM2CONDITIONS AT ABOUT 180KG\CM2

SYN COMP IS USED TO COMPRESS GAS SYN COMP IS USED TO COMPRESS GAS UP TO THAT PRESSUREUP TO THAT PRESSURE

Syn compressorSyn compressor

Gas to comp

Gas to loopGas from loop

Gas to conv26kg/cm2175

172kg/cm2

180kg/cm2

AMMONIA SYNTHESISAMMONIA SYNTHESIS

AIM AIM TO PRODUCE AMMONIA WITH THE TO PRODUCE AMMONIA WITH THE

HELP OF SYN GAS COMING FROM HELP OF SYN GAS COMING FROM METHNATORMETHNATOR

SYN GAS CONTAINS MAINLY HSYN GAS CONTAINS MAINLY H22 AND N AND N22

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

AMMONA SYN REACTIONAMMONA SYN REACTION

AMMONIA SYN REACTION IS A REVERSIBILE AMMONIA SYN REACTION IS A REVERSIBILE REACTION AND EQULIBIRIUM CONDITION IS REACTION AND EQULIBIRIUM CONDITION IS DETERMINED BY TEMP AND PRESSURE DETERMINED BY TEMP AND PRESSURE CONDITIONSCONDITIONS

IN ONE PASS THROUGH THE CONVERTOR IN ONE PASS THROUGH THE CONVERTOR ONLY 30% OF THE REACTANTS GETS ONLY 30% OF THE REACTANTS GETS CONVERTED TO THE PRODUCT SO CONVERTED TO THE PRODUCT SO REMAINING GAS KEEPS ON CIRCULATING REMAINING GAS KEEPS ON CIRCULATING

BLOCK DIGRAMBLOCK DIGRAM

GAS TO CONV

OUT LET GAS

H2 AND N2

H2 N2 AND NH3

BLOCK DIGRAM OF SYN BLOCK 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 GASAMM TO UREA

TO STORAGE

SYN GAS

What is purgeWhat is purge

AS AMMONIA SYN REACTION IS NOT AS AMMONIA SYN REACTION IS NOT COMPLETED IN ONE STEP AND GAS IS KEPT COMPLETED IN ONE STEP AND GAS IS KEPT ON CIRCULATING INERTS BUILDS UP IN THE ON CIRCULATING INERTS BUILDS UP IN THE LOOP LOOP

INERT MEANS CH4, Ar NH3 AT INLET OF INERT MEANS CH4, Ar NH3 AT INLET OF CONV THEIR CONCENTRATION SHALL NOT CONV THEIR CONCENTRATION SHALL NOT INCREASE BEYOND 14% INCREASE BEYOND 14%

SO A SMALL AMMOUNT OF GAS IS SO A SMALL AMMOUNT OF GAS IS CONTTIOUSLY WITHDRAWN FROM THE CONTTIOUSLY WITHDRAWN FROM THE LOOP THIS STREAM OF THE GAS IS CALLED LOOP THIS STREAM OF THE GAS IS CALLED PUGE GASPUGE GAS

PURGE GAS RECOVERYPURGE GAS RECOVERY

PURGE GAS CONTAINS HPURGE GAS CONTAINS H22, CH, CH44 AND AND

AMMONIAAMMONIA AMMONIA IS RECOVERED BY AMMONIA IS RECOVERED BY

WASHING THE GAS WITH WATER AND WASHING THE GAS WITH WATER AND REMAINING GAS WHICH CONTAINS CHREMAINING GAS WHICH CONTAINS CH44

AND HAND H22 IS USED IN REFORMER FIRING IS USED IN REFORMER FIRING

SYSTEMSYSTEM

PURGE GAS RECOVERYPURGE GAS RECOVERY

ABSORBER REGENERATIONR

PUURGE

WATER

STEAM

GAS TO REF

LOADED SOL

AM TO STORAGE

Installation of Plate type Combustion air Installation of Plate type Combustion air preheaterpreheater

Facilitate reduction in reformer stack temperature to Facilitate reduction in reformer stack temperature to 125125°C°C

Energy saving: 0.055 Gcal /MT NH3 Energy saving: 0.055 Gcal /MT NH3 Energy saving due to Energy saving due to a) NG saving due to increase in combustion air a) NG saving due to increase in combustion air

temperature temperature B) Reduction in steam consumption in ID FanB) Reduction in steam consumption in ID Fan

Conversion of Benfield process to GV Conversion of Benfield process to GV process process

To increase capacity and improve energy To increase capacity and improve energy effciencyeffciency

GV 2 stage process has a lower specific GV 2 stage process has a lower specific regeneration heat requirement and hence regeneration heat requirement and hence reduction in low pressure steam consumption by reduction 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 of utilization 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

New equipment in conversion from Benfield to GV New equipment in conversion from Benfield to GV section section

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 filter Mechanical filter

New machinery in conversion from Benfield to GV New machinery in conversion from Benfield to GV section section

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)

Modifications in 1Modifications in 1stst regenerator regenerator

New take off trays are installed below bed 2 New 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 mm bed height reduced by 2195 mm DemisterDemister New nozzles and instrumentation for new New nozzles and instrumentation for new

take-off traystake-off trays

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

Installation of S-50 converter Installation of S-50 converter To increase the energy efficiency of the ammonia To increase the energy efficiency of the ammonia

synthesis loop, an S-50 converter R-1502 is installed synthesis 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 new The increase in ammonia concentration exit the new converter results in a decrease in loop pressure and a converter results in a decrease in loop pressure and a lower circulation rate, which gives savings on the lower circulation rate, which gives savings on the synthesis gas compressor and the refrigeration synthesis gas compressor and the refrigeration compressor.compressor.

Energy saving: 0.18 Gcal/MT NH3Energy saving: 0.18 Gcal/MT NH3

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 same Lower circulation rate as compared to S-200 for same

loadload Higher steam generation 82 T/hr as compared to 70 T/hr in Higher steam generation 82 T/hr as compared to 70 T/hr in

S-200S-200 Lower synthesis loop pressure Lower synthesis loop pressure Lower compressor power due to less circulation and low Lower compressor power due to less circulation and low

pressure pressure Possible to achieve higher plant load with same equipmentsPossible to achieve higher plant load with same equipments

S-50 Integration in synthesis loop

Parallel Air compressor Parallel Air compressor Addition of Parallel air compressor Addition 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: 59152 Process air from Existing PAC: 59152 Nm3/hrNm3/hr

Process air from New Compressor: 6030 Process air from New Compressor: 6030 Nm3/hrNm3/hr

Total air requirement for 1750 MTPD Total air requirement for 1750 MTPD ammonia as per PFD: 65181 Nm3/hrammonia as per PFD: 65181 Nm3/hr

Ammonia-II CEP: Process air Ammonia-II CEP: Process air

As per PFD of Ammonia-II CEP, the total As per PFD of Ammonia-II CEP, the total requirement of process air from PAC of requirement of process air from PAC of Ammonia-II shall be 75683 Nm3/hr with Ammonia-II shall be 75683 Nm3/hr with distribution as follows:distribution as follows:

Process air for Ammonia-II CEP : 69234 Process 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

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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 has Based on overall performance curve of PAC, HTAS has

confirmed that the desired load shall remain within the confirmed 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 should OEM of PAC of Ammonia-II has confirmed that it should be possible to operate the machine with 75372 Nm³/h be possible to operate the machine with 75372 Nm³/h without modifications. without modifications.

It was practically observed that the machine is in position It was practically observed that the machine is in position to deliver the desired load with no limitation on driver to deliver the desired load with no limitation on driver side.side.

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LINE1 AND LINE2 DIFFERENCELINE1 AND LINE2 DIFFERENCE

LINE 1 DOES NOT HAVE MIXED FEED LINE 1 DOES NOT HAVE MIXED FEED CAPABILITY ONLY NG CAN BE USED CAPABILITY ONLY NG CAN BE USED AS FEEDAS FEED

IN LINE1 AIR COMP IS RUN BY STEAM IN LINE1 AIR COMP IS RUN BY STEAM TURBINE IN LINE 2 GT IS USED FOR TURBINE IN LINE 2 GT IS USED FOR RUNNING AIR COMPRUNNING AIR COMP


IN LINE 1 STRIPPING OF CONDENSATE IN LINE 1 STRIPPING OF CONDENSATE IS DONE BY LOW PREESURE STEAM IS DONE BY LOW PREESURE STEAM AND ALL THE STEAM IS VENTED TO AND ALL THE STEAM IS VENTED TO ATMOSPHEREATMOSPHERE

IN LINE 2 STRIIPING IS DONE BY MP IN LINE 2 STRIIPING IS DONE BY MP STEAM AND STEAM IS REUSED IN STEAM AND STEAM IS REUSED IN REFORMER THUS SAVING THE ENERGYREFORMER THUS SAVING THE ENERGY


IN LINE 1 BENFIELD PROCESS IS USED IN LINE 1 BENFIELD PROCESS IS USED FOR CO2 STRIPPINGFOR CO2 STRIPPING

IN LINE 2 GV PROCESS IS USED FOR IN LINE 2 GV PROCESS IS USED FOR CO2 REMOVAL CO2 REMOVAL

LINE 1 DOES NOT HAVE PRE LINE 1 DOES NOT HAVE PRE REFORMERREFORMER

Ammonia plant

Engineering

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