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Industrial Solutions

AmmoniaLeading fertilizer technologies

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Thepoweroftrueefficiency

The Business Area Industrial Solutions of thyssenkrupp is a world leaderforplanning,constructionandserviceinthefieldofindustrialplants and systems. Together with our customers we develop solutionsatthehighestlevelanddeliverefficiency,reliabilityandsustainabilitythroughouttheentirelifecycle.Ourglobalnetwork,witharound19,000employeesat70locations,enablesustoprovi-deturnkeysolutionsworldwidewhichsetnewbenchmarkswiththeirhigh productivity and particularly resource conserving technologies.

We are at home in many different industries. Along with chemical, fertilizer,coking,refinery,cementandotherindustrialplants,ourportfolio also includes equipment for open-cast mining, ore proces-sing and transshipment, as well as associated services. In the naval sector,wearealeadingglobalsystemsupplierforsubmarinesandsurface vessels. As an important system partner to our customers intheautomotive,aerospaceandbatteryindustries,weoptimizethevalue chain and improve performance.

Contents04 thyssenkrupp Industrial

Solutions’ ammonia experience

07 The Uhde ammonia process

08 - Steam reforming

10 - CO2 removal

11 - Ammonia synthesis

12 - Steam system

13 - Concept variants

14 - The Uhde Dual-Pressure Process

16 Proprietary Uhde equipment designs

17 - The Uhde primary reformer with a cold outlet manifold system

20 - The Uhde secondary reformer

21 - Process gas cooling train downstream of the Uhde secondary reformer

22 - Uhde ammonia converter and waste heat recovery

25 - Production and consumption figures

26 Services for our customers

27 Recent references

thyssenkrupp Industrial Solutions’ ammonia experience

ThefirstammoniaplanttouseanUhdeproprietaryprocess went on-stream at the site of the Mont-Cenis coalmineatHerne-Sodingen,Germany,asfarback as 1928. The plant had an output of 100 t/day of ammonia and comprised four reactors with a capacity of 25 t/day each, the loop operating at a pressure of 100bar.

ThefactthatthefirstUhde-engineeredammoniareac-tors were equipped with an internal heat exchanger and a synthesis loop with an integrated two-stage refrigera-tion unit deserves a special mention. Unfortunately, this efficientsystemwassoonconsideredoutdated,anditwas not until the seventies that these design principles were taken up again.

Rising energy prices have posed an increasing challenge for ammonia plant designers since this period. As early as 1968, Uhde took up the challenge and engineered a plant with an energy consumption of only 7.8 Gcal per tonne of ammonia.

Thisnaturalgas-basedplantwithacapacityof880t/dayincorporated the following essential elements for reducing energy consumption:

• Maximum heat recovery from the primary reformer fluegasbycoolingitto135°Catthestackinlet.

• Preheatingofthecombustionairfortheprimary reformer.

• Generationof125barsteamfromprocesswaste heat downstream of the secondary reformer and in the ammonia synthesis unit.

• High-pressure steam superheating with waste process heat downstream of the secondary reformer.

• Three-bedammoniareactorwithheatexchangers betweencatalystbeds.

Allsubsequentammoniaplantsdesignedby thyssenkrupp Industrial Solutions have incorporated most of these low-energy features.

In recent years, ammonia plant technology has under- goneradicaldevelopmentsintermsofbothdesignandequipment.Inordertoimproveplantefficiency,efforts

havehadtobefocusedonreducingpowerconsump-tion, improving process heat recovery, minimising stack lossesandcuttingenergyconsumptionforCO

2 removal.

Thecompany'sobjectiveofmakingasubstantialim- provementinenergyefficiencyhasreliedheavilyonexperienceandinvolvedabroadspectrumoftechnicalexpertise including a technical review of process design, engineering design, research and development and the evaluation of operating data. Equally important has beentheenhancementofplantoperabilityandrelia- bility.Hence,muchattentionhasbeenpaidtopastsuccessful experience and proven energy-saving features.

In1998,UhdejoinedforceswithSynetix,nowJohnsonMattheyCatalysts(JMCatalysts),tofurtherimprovetheUhdeammoniaprocess.Thispartnershipbuildsonthetraditional strengths of the two companies and takes advantageofJMCatalysts'know-howincatalysis,am-monia plant operation and support services together withtheexperienceindesign,engineeringandprojectexecution that thyssenkrupp Industrial Solutions can offer.ThepartnershipallowsstrongcollaborationbetweenJMCatalystsandthyssenkruppIndustrialSolutions' engineers so that the Uhde ammonia process canbefurtheroptimisedtotakebestadvantageofthelatesthigh-performancecatalystsfromJMCatalysts,thusimprovingefficiencyandloweringcost.

The most recent successful implementations of the Uhde ammonia process include a plant in Turkmenistan with a capacity of 600 t/day, a 2,000 t/day plant for Qatar FertilizerCo.(QAFCO)inMesaieed,Qatar,seven 1,200 t/day plants in Egypt, a 2,000 t/day plant in the UAE(FERTIL2)anda2,200t/dayplantinIowa,US,which is under construction.

A new milestone in ammonia technology was achieved withtheplantbuiltforSaudiArabianFertilizerCompany(SAFCO)inAlJubail,SaudiArabia.Itwasthefirstplanttobebasedonthe"UhdeDual-PressureProcess"and,with a single-train capacity of 3,300 t/day, it was and still is one of the world's largest ammonia plant. Built in 2006,ithassincebeenmarginallytoppedbyanUhdeDual-PressureplantbuiltinSaudiArabia(MAADENI).Two other plants of this type and capacity are currently underconstruction,oneinSaudiArabia(MAADENII)and the other in Louisiana, US.

4

ProcessflowsheetofUhde’sfirstammoniaplant

in Herne, Germany, completed in 1928

Ammonia plant in fertilizer complex

in Tecen, Turkmenistan

Capacities: 600 t/day of ammonia

1,050 t/day of urea synthesis

1,050 t/day granulation unit

5

1,500 t/day ammonia

plant and fertilizer complex,

Saskferco, Canada

6

7

The Uhde ammonia process

TheblockdiagramofanUhdeammoniaplantfoundbelowshowstheconventionalsequence of process steps that form the basisofmostpresent-dayammoniapro- cesses. However, ammonia processes cannotbejudgedsolelyonthebasisofa blockdiagram.Amoredetailedscrutiny ofthefactsandfiguresshowsthatwhatappearstobeaconventionalset-upisinfact a state-of-the-art ammonia plant concept.

Thetotalconsumptionfigure(feed+fuel+electricpower)permetrictonofammoniaproduced is in the range of 6.4 to 7.2 Gcal (26.8-30.1GJ),dependingonlocalcon- ditions(e.g.coolingwatertemperature)andproject-specificrequirements(suchasthenaturalgasprice,etc.).

The following process areas have under-gonemajormodificationsinordertoachievethesefigures:

• Steam reforming section including its waste heat recovery system.

• Steam system.

• Optionalgasturbinedrivefor the process air compressor.

• CO2 removal unit.

• Ammonia synthesis unit.

Assumingthereadertobefamiliarwiththe basicsofammoniatechnology,attentioninthefollowingsectionshasbeenrestrictedtothoseaspectsspecifictotheUhdelow-energy concept.

Block diagram

of an Uhde ammonia plant

Desulphurisation

Primary reformer

Secondary reformer

CO shift

CO2 removal

Methanation

NH3 synthesis

H2 recovery

Refrigeration

Natural gas feed

Fuel Process steam

Process air

Syngas compressor

H2 to syngas compressor

Combustionair

HP steamsuperheated

BFW

CO2

HP steam tosuperheater

NH3

Product

Fuel

7

The Uhde ammonia processSteam reforming

Thefollowingmodificationstoconventionalplant designshavecontributedtoimprovementsinoverallefficiency:

• Shift of part of the reforming reaction from the primary to the secondary reformer as a result of the following measure:

Installationofapurgegasrecoveryunit,bymeans of which hydrogen is recycled to the suction side of thesyngascompressor,therebyallowingoperation of the secondary reformer with excess air while the hydrogen-to-nitrogen ratio of the make-up gas is kept close to 3:1.

• Preheating of the process air for the secondary reformertoahighertemperatureofupto600°C. Shifting part of the reaction to the secondary reformer leads to lower operating temperatures in the primary reformer and therefore to fuel savings.

• Optimumuseofthereducedprimaryreformerload isachievedbyincreasingthereformerpressureto about44barwhilstmaintainingtheestimatedlife- timeofthereformertubesat100,000hours.This step entails a reduction in overall energy consumption as the aggregate power required for the synthesis gas compressor is reduced.

• Increase in the feed / steam mixture preheat temperature.Thisreducesthefiringrequirementsinthe primaryreformerbyshiftingtheheattransferduty from the radiant section to the convection section.

• Decreaseinthesteam-to-carbonratioto3.0.This includes an adequate safety margin against the formationofcarbondepositsontheprimaryrefor- mer catalyst. Reducing the admixture of steam to thefeedresultsinlessheatbeingabsorbedinthe primary reformer radiant section and therefore lower fuelconsumption.Nevertheless,thesteam-to-gas ratioishighenoughtominimiseby-productforma- tion in the HT shift through the use of commercially proven catalysts.

The process data of the reforming section aresummarisedbelow:

Steam/carbonratio 3.0

Feed/steam,primaryreformerinlet °C 530-580

Pressure,primaryreformerexit bar 39-43

Methane, primary reformer exit vol.% 10 - 13

Methane, secondary reformer exit vol.% 0.3 - 0.6

Processairtemperature °C 520-600

Combustionairtemperature °C 250-440

125barsteam,superheated °C 530-540

Stacktemperature °C 120-180

Primary and secondary

reformer of the AFC

ammonia plant in Egypt.

8

Specialmentionshouldbemadeofanessentialitem of equipment in the steam reforming section: the steam superheater, located in the process train downstream of the secondary reformer.

Inalow-energyplant,theobjectiveistorecoverasmuchheataspossiblefromtheconvectionsectionfordirectprocessuse,therebyreducingthefuelrequire-ment.ThisreducestheheatavailableintheconvectionsectionforsuperheatingHPsteam.Thebalanceoftheenergy required for this purpose is therefore recovered in the superheater downstream of the secondary re-former. The duty of this superheater is in the range of15to40%oftheheatavailablebetweenthesecond-ary reformer exit and HT shift inlet, depending on the process parameters selected.

Thelowerthefuelconsumptionfigure,themoreprocessgas heat is utilised to superheat the HP steam, whereas the total HP steam generated is reduced. In other words: fuel savings also reduce the net energy export.

AsuperheaterofthistypewasinstalledbywhatwasthenUhdeforthefirsttimeintheGewerkschaftVictorplant, which went on stream in 1970. This same design configurationwasalsousedfortheCILplantinCanada(on-streamsince1985)andisnowthesuperheaterofchoiceinalloftheammoniaplantsrecentlybuiltbythyssenkrupp Industrial Solutions. Firstly this arrange-mentprovidesthenecessaryflexibilitytoadapttheplantto any given set of process requirements, and secondly, itenablesthesteamsystemtooperatesafelyunderanynormal,orabnormal,operatingconditions.

Aninternalbypassintheevaporationsectionpermitstheshiftingofheattransferdutybetweentheevapora-tor and the steam superheater. In normal operation, the internalbypassremainspartiallyopen.Byclosingit,thegastemperatureatthesuperheaterinletcanbere- duced, thus increasing steam generation. This is important in overcoming partial plant failures, e.g. in the case of a loss of steam production in the ammonia synthesis section.

� ��

Fuel

HP steam

Feed

Desulphurisation

MP steam

Process air

Combustion air

Reformer

Secondaryreformer

Steam drum

LT shift HT shift

HP steam

BFW

Process gas

BFW

Convection bank coils� HP steam superheater� Feed/steam preheater� Process air preheater� Feed preheater� Combustion air preheater

HP steamsuperheater

Processgas cooler

Steam reforming

andCOshift

9

The Uhde ammonia process CO

2 removal

VariouschemicalandphysicalabsorptionsystemsareavailablefortheremovalofCO

2, e.g. aMDEA®,Benfield,

Amine Guard and Selexol. thyssenkrupp Industrial Solutions has used all these processes in the past and has the experience of many years of commercial operation. The lowest energy consumption is achieved using theOASEWHITE®processlicensedbyBASF.Thekey to these energy savings is that the solution is primarily regeneratedbyflashingratherthansteamstripping.

TheactivatedOASEWHITE® process uses a solution of N-methyldiethanolamineandwaterwithaspecialactiv-

Thedesignselectedincorporatesatwo-stageabsorber.MostoftheCO

2 is removed in the lower part using a

semi-leansolutionthathasbeenregeneratedinatwo- stageflashloopwithoutanyneedforstrippingenergy.Finalpurificationtotheppmrangethentakesplaceintheupperpartoftheabsorberwitharelativelysmallpor- tion of the total circulating solvent. It is only this portion thathastobethermallyregeneratedbyastrippingpro- cessinareboilingcolumn.ThisprocessschemepermitsareductioninthespecificenergyconsumptionoftheCO

2 recoverysystemto1,340kJ/Nm3ofCO

2 (13,000

BTU/lbmoleofCO2).

ator as the solvent. As the activated MDEA solution isothermsforCO

2arebetweenthoseofatypical

chemical solvent and a physical solvent, this process combinesthebenefitsofbothchemicalandphysicalCO

2 removal processes.

In addition, the process offers the following advantages:

• HighCO2recoveryrate(>96%)andCO

2 purity

(>99%byvolume).

• Noneedforcorrosioninhibitorsasthesolutionis notcorrosivetocarbonsteel.

• MinimisationofsolutionlossesbecauseactivatedMDEA has a low vapour pressure and does not degradeduringoperation.Noreclaimingofthesolution is required.

• Notoxicsolvents.

• Nocrystallisationproblems.

Process gas

LP steam

Fuel

CO2 (high purity)

Stripper

Flashvessel

C.W. C.W.

Absorber

Pure

gas

aMDEA®CO2

removal system

10

The most fundamental improvements to earlier designs havebeeneffectedintheammoniasynthesisunit.

The main feature of this unit is its high conversion rate whichisachievedbyalargecatalystvolume.Inordertominimise reactor size and cost while keeping the pressure drop low, the large catalyst volume requires:

• Use of small grain-size catalyst.

• Applicationoftheradial-flowconceptinthe ammonia reactor.

thereforeusesonlywell-provenmagnetite-basedcata- lystsinallthreebeds.Thefirstofthethreebedswilltypicallybefilledwithprereducedcatalysttoacceleratethe initial start-up.

Dependingonthesite-specificandproject-specificcon- ditions,thethreecatalystbedsarearrangedineitherone or two ammonia reactors.

Designs with one ammonia reactor and one waste heat boilercannotoptimallyexploitthereactionheatforthegeneration of high-pressure steam. However, optimum heatrecoverycanbeachievedifanadditionalwasteheatboilerisintroducedbetweenthesecondandthirdbed.

This arrangement improves the gas-side temperature of theboilersandprovidesanadditionaladvantageinthat

Uhdehasalwaysadvocatedthree-bedreactorswithhighammonia conversion rates per pass. Therefore, the Uhde ammoniasynthesisunitisbasedonathree-bedreactorsystem,eachbedwitharadialflow.Ahigh-conversionsynthesisloopoffersconsiderableadvantagessincetherecyclegasquantityisconsiderablyreducedand,consequently, power requirements for the circulator are lower and heat exchanger surfaces smaller. Refrigeration re- quirementsalsodecreaseoverproportionatelybecausemost of the ammonia produced is condensed upstream of the loop chiller.

Studiesoninnovativehigh-activitypreciousmetal-basedcatalysts have revealed that no economic advantage can begainedthroughtheiruseinviewoftheuncertaintyoffuture prices for the precious metals required. Further-more, due to the different physical properties operational problemscanbeexpected.Formaximumreliabilityandcost-effectiveness thyssenkrupp Industrial Solutions

itpermitsahigherboilerfeedwatertemperatureattheboilerinlet,whichmeansthatthepreheatingoftheboiler feedwatercanbeenhancedbyusingthelow-levelheatavailableinotherplantsections,forexampledownstreamof the LT shift.

Theeffectofatwo-boilersystemonhigh-pressuresteamgenerationissignificant:itisincreasedfrom1.1to1.5t / t of ammonia. The process parameters of the synthesisloopdesignareshownbelow:

HP steam

BFW

Make-up gas

C.W.

Ammonia converter

Syngas compressor

NH3

(liquid)

Purge

The Uhde ammonia process Ammonia synthesis

H2 /N

2 ratio, methanation exit 2.95

Synthesislooppressure bar 140-210

NH3 reactor inlet vol.% 3 - 5

NH3 reactor outlet vol.% 20 - 25

HPsteamgeneration t/tNH3 1.1 - 1.5

Numberofreactors 1or2

Ammonia synthesis

11

The Uhde ammonia process Steam system

Process gas Flue gas

HP steam header

112 bar, 530 °CTurbine syngas compressor

Turbine process aircompressor and alternator

C.W. Surface condenser

Condensate pump

Condensatetreatment

MP steam header

415 °C, 49 bar

Process gas

Process gas

Process steam

LP steam consumers

LP steam header

BFW pump

Steam drum125 bar

NH3

synthesis

BFW

Condensate

Process gas

The diagram shows the heat management system un-derlying the Uhde low-energy ammonia plant concept, the essence of which is the optimum utilisation of process waste heat for the generation of superheated high-pressure steam.

High-pressureboilerfeedwaterisheatedinafirststepdownstream of the LT shift; the stream is then split into two, one part-stream going to the ammonia synthesis unit and the other to the HT shift for further preheating.

High-pressure steam is only generated from process waste heat at two locations:

• Downstream of the secondary reformer.

• In the ammonia synthesis unit.

Superheating of high-pressure steam takes place downstream of the secondary reformer and in the primaryreformerconvectionbank.

The superheated steam is expanded in the high-pres-surepartofthesyngascompressorturbineandfedtothe medium-pressure system.

Medium-pressuresteamat49bar,415°C,isusedasprocess steam or for the following equipment:

• Condensingturbinethatdrivesthesyngas compressor.

• Condensingturbinethatdrivestheprocessair compressor / alternator.

• Back-pressureturbinedrivingtheboilerfeed water pump.

Depending on the plant requirements, the process air compressorturbineortherefrigerationcompressorturbinecanbefedwithHPsteam.Allothermachinesaredrivenbyelectricmotors.

Further reduction of the overall energy consumption is achievedbyapplicationofagasturbinedrivecombinedwith a heat recovery system.

Steam system

12

The Uhde ammonia process Concept variants

Theplantconceptpresentedhereconstitutesthebasisof the Uhde low-energy ammonia technology. The designcaneasilybeadaptedtosuitthespecificconditionsofanyproject.Variationsmayrangefromminorprocessmodifications(e.g.inthesteamsystem)tothereplace-mentofentireunits(e.g.substitutionoftheaMDEA® CO

2removalsystemforanAmineGuard,Benfieldor

Selexolunit).

13

The Uhde ammonia process The Uhde Dual-Pressure Process

Chemicalplantcapacitieshaveforalongtimebeentaking on ever greater dimensions. The reason for this isthereductionofthespecificproductioncoststhrougheconomiesofscale.Morethaneverbefore,theplantconstruction sector is facing the challenge of exploiting this advantage while at the same time continuing toemploy proven technologies and equipment.

thyssenkruppIndustrialSolutionsandJohnsonMattheyCatalysts have risen to this challenge and developed a processbasedonexistingtechnologywhichnowenablesammonia plants to produce very large capacities. This newprocess(seeflowsheet)deliversacapacityof3,300 t/day using well-tried and tested equipment. Italsoprovidesthebasisforevenlargerplants(e.g.4,000-5,000t/day).

ThefirstplanttoapplythisprocesswastheSAFCOIVammoniaplantinAl-Jubail,SaudiArabia.Withaca- pacityof3,300t/dayitwasbyfarthelargestammoniaplantworldwide.Theplanthasbeeninoperationsince2006.AsecondplantbasedontheDual-PressurePro- cess came on stream with a similar capacity in 2011 and the next two plants are under construction.

The key innovation of the Uhde Dual-Pressure Ammo- nia Process is an additional medium-pressure once- through ammonia synthesis connected in series with the conventional high-pressure ammonia synthesis loop as follows:

1. The once-through ammonia synthesis involves compression of the make-up gas in a two-stage intercooled compressor. This is the low-pressure (LP)casingofthesyngascompressor.Thepressure atthedischargeofthecompressorisabout110bar. Atthispressurethethree-bed,intercooled,once- through converter produces approximately one third of the total ammonia output. The syngas-ammonia mixture leaving this converter is cooled and 85% of the ammonia produced is separated from the gas as liquid.

2. The remaining syngas is then compressed in the high-pressure(HP)casingofthesyngascompressor to the operating pressure of the ammonia synthesis loop(upto210bar).Sincethesyngashasbeen cooled down the HP casing can operate at a much

lower temperature than in the conventional ammmo- nia process. The high synthesis loop pressure is achievedthroughacombinationofthechilledsecond casing of the syngas compressor and a slightly elevated front-end pressure. In this conventional ammonia synthesis loop the remaining two thirds of the total ammonia is produced.

Technology highlights

• Well-provenmagnetite-basedcatalystscanbeused in all stages of the new process.

• Energyefficiencyisimprovedby4%comparedtothe conventional Uhde process.

• A high conversion rate in the high-pressure synthesis loopcombinedwiththereducedproductionrequire- ment results in reduced piping sizes in the high-pres- sureloop.Standardpipingcanbeusedforcapacities of 4,000 t/day and more.

• The syngas compressor of a 3,300 t/day dual- pressure plant is the same size as that in current 2,000 t/day ammonia plants; several reference compressors are in operation.

• Only2/3ofthehydrogenrecoveredfromthepurge gashastoberecompressedtotheloop;1/3iscon- verted to ammonia in the once-through synthesis.

• Theprocessdesignisextremelyflexiblewithalarge numberofprocessparametersavailabletooptimise the use of catalyst and machinery.

• Itisnowpossibletoachieveasynthesiscapacityof about3,300t/dayofammoniausingconventional equipmentandcatalyststhathaveprovedtobereliable andefficientinexistingplants.

• Therearenomajordeviationsfromprovenprocess conditions.

• The front-end of the plant is very similar to the conventional Uhde design except that it operates at a pressureofabout3barhigher,aprocessconditionwhich is well within our proven long-term design and operating experience.

14

Secondammoniaconverter

LPcasing

HPcasing

Once-throughammonia converters

Off-gas

PGR unit

Firstammoniaconverter

HPsteam

HPsteam

CW

~ 110 bar

Purge gas recovery

NH3 chiller NH3

AmmoniafromHP loop

HPsteam

NH3 chiller

Ammonia from once-through conversionNH3 chiller

NH3chiller

CW

CW

Note: Molecularsieves (dryers)not shown

H2O

Make-up gas from front-end

~ 210 bar

NH3

Low pressure sectionHigh pressure section

The Uhde Dual-Pressure Ammonia Process

15

Proprietary Uhde equipment designs

Agoodprocessaloneisnotsufficient.

Itisatleastasimportanttohaveprovenandreliabledesignsforcriticalitemsofequipment.Onlythetwocombinedwillmakeagoodplant.

thyssenkrupp Industrial Solutions has pioneered the development of essential items of equipment for ammonia plants and is one of the leading contractors inthisfield.Thesedevelopmentsinclude:

• Primary reformer with a cold outlet manifold system.

• Secondary reformer.

• Process gas cooling train downstream of the secondary reformer for - generating high-pressure steam - superheating high-pressure steam.

• High-efficiencyammoniaconvertersystemwiththree beds,indirectheatexchangeandradialflow.

• Ammoniasynthesiswasteheatboiler.

thyssenkrupp Industrial Solutions holds, or has pending,anumberofpatentsforsuchequipmentandhas granted numerous manufacturing and marketing licences to equipment manufacturers and chemical engineering contractors.

Inlet manifold

Burners

Reformer

tubes

Cold outlet

manifold system

Process air

Water jacket

Refractory

Catalyst bed

Gas outlet

Primary reformer Cold outlet manifold system

Secondary reformer

Reformer radiant section, outlet

manifold system and secondary reformer

16

Proprietary Uhde equipment designs The Uhde primary reformer with a cold outlet manifold system

The Uhde primary reformer is a furnace in which amultiplicityoftubesfilledwithcatalystareheatedbyburningfuel.Theprocessgastemperaturerequired attheoutletofthecatalyst-filledtubesisabout800°C atapressureofapproximately45bar.Inevitably,theservicelifeofcomponentssuchasthereformertubes is limited. Material deterioration occurs through the combinedeffectsofcreep,alternatingthermalandmechanical stresses, external and internal oxidation andcarburisation.

Consequently, the furnace designer is faced with two main tasks:

• Firstly,tominimisethenumberofcomponents subjecttowearandtearduetothecombinedeffectsof high temperatures and pressures.

• Secondly, to allow as smooth and safe an operation aspossible.

The following main features show our approach to fulfillingtheaboverequirements:

• Top-firingforanoptimumuniformityofthetubeskin temperatureprofile.

• Smallnumberofburners(incomparisonwitha side-firedreformer).

• Internally insulated cold outlet manifold system made fromcarbonsteelandlocatedexternallyunderthe reformerbottom.

• Internallyinsulatedreformertube-to-manifoldconnection which operates at moderate temperatures.

• Eachtuberowisconnectedtoaseparateoutlet manifold.

Advantages of the Uhde reformer:

• Nohigh-alloyoutletpigtailsand/oroutletmanifolds or risers which work at creep conditions.

• Minimumnumberofcomponentsexposedtothe severe process conditions.

• Uniformtemperatureprofileovertheentirelength ofthereformertubewiththelowestpossiblepeak temperature, resulting in optimum utilisation of the reformertubematerial.

• Nothermalexpansionproblemswiththeoutletmani- fold system. The slight remaining thermal expansions donothavetobecompensatedbymaterialsexposed to the severe process conditions. The design of very largesingle-boxreformersispossible.

• The process gas outlet temperature is monitored for eachtuberowandisadjustableduringoperationfor optimum reformer performance and temperature uniformity.

• Almost unlimited service life of the Uhde outlet manifold system with no maintenance required other than painting.

• Considerableoperationalallowanceoftheoutlet manifold system with regard to process gas temperature and pressure.

Morethan60reformersofthistypehavesofarbeendesigned and constructed since 1966. All have per- formed excellently. The two largest units are equipped with630and960tubes,respectively.

Skin temperature [°C]300 600 900

Refractory

Feed/steam

Furnace arch

Reformer tube

Fire box

Catalyst grid

Furnace bottom

Bellow

Gas conducting tube

Shop weld

Field weld

Carbon steel

Outlet manifold

Skin temperatureprofile

Reformertube-to-manifoldconnection

withskintemperatureprofile

17

Fertilizercomplexno.4(SAFCOIV)forSaudi

ArabianFertilizerCompanyinAlJubail,SaudiArabia

Capacities: 3,300 t/day of ammonia

3,250 t/day of urea


19

Proprietary Uhde equipment designs The Uhde secondary reformer

Combustionzone

Arch

Refractory

Catalyst

Process air

Process gas

Process gas

Water jacket

Secondary reformer

CFD optimisation

Particularly challenging areas in secondary reformer design include:

• The transfer line from the primary reformer outlet to the secondary reformer.

• The refractory lining including the ceramic archwhichbearsthecatalystweight.

• Theburners.

thyssenkrupp Industrial Solutions’ answer to a safe and reliablesecondaryreformercomprisesthefollowingfeatures:

• Arefractory-linedtransferlinebetweentheprimaryand secondary reformer, which is only short as it is connected to the process gas inlet nozzle of the secondaryreformer.Onceinthesecondaryreformer,the gas passes through an central internal riser into thecombustionchamber.Thisdesignfacilitatesductingandeliminatesthermalstressbetweenthetransfer line and the secondary reformer.

• A multi-layer refractory lining with high-alumina bricksinthehotzones.

• Aring-shapedarchmadeofhigh-aluminabricksthat providesahighlystablesupportforthecatalyst.Due to the internal riser, the arch spans only half of the vesseldiameter,resultinginimprovedstabilitycom- pared to other designs.

• Amultiplenozzleburnersystemcomprisedofnozzles equallydistributedroundthecircumferenceofthe combustionchamberattwolevels.

• Discharge of the process gas from the central internal riserintothedomebyreversingtheflowdirection.Air isaddedviaaspecificnumberofnozzlesinstalledin thevesselwallatadefinedangle,thuscreatinga vortexflowinthecombustionchamber.Thevortex flowensuresoptimisedmixingofairandprocessgas. Theflamesdonotcomeintocontactwiththevessel refractory or the central riser pipe.

• Aproprietaryburnerdesign,firstappliedin1992, which avoids any metallic parts coming into contact with the hot reacting process gas.

Since its introduction in 1968, the Uhde secondary reformerhasprovedtobeareliableitemofequipmentwith a long service life.

The process gas leaving the primary reformer enters the secondaryreformeratthebottom.Thegasisroutedthroughthecentralinternalriserpipeintothecombustionchamberatthetopofthesecondaryreformer.Processairisintroducedintothiscombustionchambervianoz- zles, arranged at equal intervals round the circumference ofthecombustionchamberintworows.Thepartiallyoxidisedgaspassesthroughthecatalystbedfromtoptobottom,thecatalystbedbeingsupportedbyaceramicarch. Finally, the gas leaves the secondary reformer throughtheoutletnozzleatthebottom.

20

Proprietary Uhde equipment designsProcess gas cooling train downstream of the Uhde secondary reformer

Theprocessgasfromthesecondaryreformerhastobecooledfrom1,000°CtoacontrolledtemperaturesuitableforthedownstreamCOshift.Thesensibleheatcanbestbeutilisedinthegenerationandsuperheatingofhigh-pressure steam.

Thechallengeindesigningsuitablecoolingtrainequip- ment is to arrive at a concept which provides safe temperature limitation for all parts according to their particular load sensitivity and materials of construction. In addition, theequipmentshouldbeavailableatcompetitiveprices.

Since1966,thyssenkruppIndustrialSolutionshasbothusedandpromoteduseofthehorizontalfire-tubeboilerfor this purpose. In 1969, the process gas cooling train wasfirstmodifiedtoincludeahigh-pressuresteamsuperheater.

Features of the Uhde process gas cooling train

Horizontalfire-tubeboilerwith:

• Thinflexibletube-sheetdesign.

• Full-penetrationtubetotube-sheetswelds.

• Tubeinletsprotectedbyferrulestolimittheheadflux atthetubeinlet.

• Doublelayerrefractoryliningfortheinletand,if necessaryfortheoutletchamberwithhigh-duty bricksonthehotsurface.

• Internalgasbypassfortemperaturecontrolwith steam-cooleddamperblades.

• Steamdrummountedontopoftheboilerand supportedbydowncomersandrisers.

High-pressure steam superheater with:

• Processgasinletandoutletatthebottom.

• Preferablyverticalarrangementofthesuper- heating coil.

• Pressure shell in contact with the cooled process gas only.

• Internalbypassfortemperaturecontrol.

Advantagesofthehorizontalfire-tubeboiler:

• Simple,fixed-tubesheetdesign.

• Nocrevicecorrosion.

• Reliablenaturalwatercirculation.

• Noheateddeadendsonwatersidewheredebris can settle.

• Lowmetaltemperaturesatandneartubesheetsdue toefficientinsulationandferrules.

• Simpleandreliableprocessgastemperaturecontrol.

• Easy access for inspection and maintenance.

• Lowerectioncostsduetoshopassemblyofboiler and drum.

Advantages of the high-pressure steam superheater:

• Coildesignedforhighmechanicalflexibility.

• Thermal expansions compensated for within the coil.

• Safemetaltemperaturesmaintainedbyefficient bypasscontrol.

• Temperatureofthepressure-bearingshellgoverned bycooledoutletgas.

• Simple steam and process gas temperature control.

Uhde secondary reformer and process gas cooling train

21

Proprietary Uhde equipment designsUhde ammonia converter and waste heat recovery

Fertilizer complex of

EFC in Ain Shukna

(nearSuez),Egypt.

Capacities:

1,200 t/day of ammonia

1,925 t/day of urea


Thedemandforenergy-efficientammonia production dictates the following criteria for the design of the ammonia synthesis unit:

• High conversion rates and therefore large catalyst volume.

• Maximum utilisation of reaction heat for the generation of high-pressure steam.

• Low pressure drop in the loop.

Such criteria, in turn, call for the:

• Useoffine-particle catalyst.

• Applicationoftheradial-flow principle.

• High-pressure steam gen- erationwhereverfeasible.

The Uhde ammonia synthesis design therefore incorporates threeradial-typecatalystbedsarranged in either one or two ammonia converters.

Features of the Uhde single-converter design:

• Heatexchangerbetween catalystbedsforindirect cooling of synthesis gas; consequently,highlyefficient temperature control.

• Radialflowfromoutsideto inside through all catalyst beds.

• Designadaptabletofull-bore or drawn-in top closure of converter, depending on projectconstraints.

• Heatexchangersextractable without removal of cartridge.

• An externally arranged BFW preheater/HPsteamboiler downstreamofthethirdbed.

Features of the Uhde two-converter design:

• Locationofthefirsttwo catalystbedsinthefirst converter vessel and of the thirdbedinthesecond converter vessel.

• Radialflowfromoutsideto inside through all catalyst beds.

• SimpleU-tubeheatex- changerbetweenfirstand secondcatalystbedsfor indirect cooling of the synthesis gas.

• Designadaptabletofull-bore or drawn-in top closure of converter, depending on projectconstraints.

Start-up gas

Gas inlet

Bypass

control

First bed

Second bed

Third bed

Gas outlet

Start-up gas Gas inlet

First bed

Second bed

Gas outlet

Left:

Three-bedammonia

converter,radialflow

Right:

AmmoniaconverterI,radialflow,

catalystbeds1and2

22

• Easy withdrawal of internal heat exchanger without removing catalyst.

• Smaller dimensions and lower weight of vessels to reduce transport and handlingproblems.

• AnexternalHPsteamboiler downstream of the second catalystbed.

• An externally arranged BFW preheater/HPsteamboiler downstreamofthethirdbed.

Features of the Uhde HP steam boilers:

• Tubesheetcoolingtoprevent nitriding.

• Channels in contact solely with the cooled synthesis gasleavingtheboiler.

• FreelymovableU-tube designofthebundle.

• Internalborewelding,the heatexchangertubesbeing joinedtothetubesheetby means of full-penetration welds.

• Steam/boilerwatersepar- ation in the upper part of the wasteheatboiler.

The design of HP synthesis loopboilersisalong-standingtradition at thyssenkrupp Indus-trialSolutions,datingbackto1969 when equipment of this type was pioneered.

Advantages of Uhde HP steam boilers:

• Allcomponentsfabricated from hydrogen-resistant, easy-to-handle, low-alloy materials.

• Elimination of stress corrosion cracking and crevice corrosion.

• Low thermal stress.

• Integratedboilerfeedwater preheating.

• Tube-to-tubesheet weldsallsubjectedto non-destructive tests.

Third bed

Gas outletGas inlet

Steam outlet

Gas outletGas

inlet

BFW inlet

Temp.

blow down

Cont.

blow downBFW

bypass

Vane

separator

Ammonia converter II ,

radialflow,catalystbed3 HPSteamboiler

23

Sorfert Algeria fertilizer complex.

Capacities: 2 x 2,200 t/day of ammonia

1 x 3,450 t/day of urea

24

OverallviewoftheQAFCO4

ammonia / urea complex

successfully commissioned

byUhdebackin2004.

Capacities:

2,000 t/day of ammonia

3,200 t/day of urea


Proprietary Uhde equipment designsProductionandconsumptionfigures

Feed and Energy Consumption

Naturalgasasfeedandfuel ....................Gcal(1) .............. 6.8 ....to ...... 7.4Electric power ........................................kWh............... 15 .......to ....90Overallfeedandenergy(2) ........................Gcal(1) .............. 6.4 ....to ...... 7.4

Utilities

Cooling water ( T=10K) .......................mt ............... 120 .......to .. 260Demineralisedwater(netcons.) ...............mt ................... 0.65 ..to ...... 0.75

Effl uents

Treated process condensate(3) ..................mt ................... 0.85 ..to ..... 1.15

Product Quality

Ammonia content ...................................%bywt. ........ 99.8 ....to ...100.0Water content .......................................%bywt. ........ 0.0 ....to ...... 0.2Oilcontent.............................................ppmbywt. ...............max. ... 5

(1)expressed as lower heating value of natural gas per metric ton of ammonia(2) electric power and steam export converted into fuel equivalents(3)routedbacktothedemineralisationunitforre-use

Allconsumptionfiguresarepermetrictonofliquidammoniaandserveasgeneralinformationonly.Localclimaticconditionsandgascompositionmayhaveaconsiderableinfluenceontheperformancefigures.

25

thyssenkrupp Industrial Solutions is dedicated to pro-viding its customers with a wide range of services and to supporting them in their efforts to succeed in their lineofbusiness.

With our worldwide network of local organisations and experienced local representatives, as well as first-class backingfromourheadoffice,wehavetheidealqualifi-cations to achieve this goal.

We at thyssenkrupp Industrial Solutions place particu-lar importance on interacting with our customers at an earlystagetocombinetheirambitionandexpertisewith our experience.

Whenever we can, we give potential customers the op-portunity to visit operating plants and to personally eval-uatesuchmattersasprocessoperability,maintenanceandon-streamtime.Weaimtobuildourfuturebusi-ness on the confidence our customers place in us.

We provide the entire spectrum of services associated withanEPCcontractor,fromtheinitialfeasibilitystudy,throughfinancingconceptsandprojectmanagementright up to the commissioning of units and grassroots plants.

Ourimpressiveportfolioofservicesincludes:

• Feasibilitystudies/technologyselection.

• Projectmanagement.

• Arrangement of financing schemes.

• Financialguidancebasedonanintimate knowledge of local laws, regulations and tax procedures.

• Environmental studies.

• Licensingincl.basic/detailengineering.

• Utilities / offsites / infrastructure.

• Procurement / inspection / transportation services.

• Civil works and erection.

• Commissioning.

• Training of operating personnel using operator training simulator.

• Plant operation support / plant maintenance.

• RemotePerformanceManagement(Teleservice).

Weliketocultivateourbusinessrelationshipsandlearnmoreaboutthefuturegoalsofourcustomers.Ourafter- sales services include regular consultancy visits which keeptheownerinformedaboutthelatestdevelopmentsor revamping options.

Ourpolicyistoensureutmostqualityintheimplemen-tationofourprojects.Weworkworldwidetothesamequality standard, certified according to:

DIN/ISO9001/EN29001.

We remain in contact with our customers even after projectcompletion.Partneringisourbyword.

By organising and supporting technical symposia, we promoteactivecommunicationbetweencustomers,licensors, partners, operators and our specialists. This enablesourcustomerstobenefitfromthedevelopmentof new technologies and the exchange of experience aswellastroubleshootinginformation.

thyssenkrupp Industrial Solutions stands for tailor-made concepts and international competence. For more information contact one of the thyssenkrupp IndustrialSolutionsofficesnearyouorvisitourwebsite:

www.thyssenkrupp-industrial-solutions.com

Services for our customers

26

Recent references

Completion Customer Plant Site Plant Capacity Contract Project Notes

2016 DaelimforSaudiArabian RasAlKhair, Ammonia 3,300t/day E,P MiningCompany,Ma'aden SaudiArabia

2016 CFIndustries PortNeal,USA Ammonia 2,200t/day E,P

2015 CF Industries Donaldsonville, USA Ammonia 3,300 t/day E, P

2013 Samsung for Ruwais Ruwais, Ammonia 2,000 t/day E, P FertilizerIndustries AbuDhabi,UAE

2014 EgyptianAgriumNitrogen Damietta, Ammonia 2x1,200t/day Turnkey Products Co. SAE Egypt (EAgrium)

2013 OrascomConstruction Arzew, Ammonia 2x2,200t/day E,P Industries for Sonatrach Algeria OrascomFertilizer Company(Sorfert)

2011 Samsung for Saudi Ras Al Khair, Ammonia 3,300 t/day E, P ArabianMiningCompany, SaudiArabia Ma'aden

2008 MisrOilProcessingCo. Damietta, Ammonia 1,200t/day Turnkey Egypt

2008 KuibyshevAzot Togliatti, Ammonia 1,800t/day E Expansion Russia

2007 Duslo a.s. Sala, Ammonia 1,300 t/day E Expansion Slovakia Expansionby 300t/day

2007 Helwan Helwan, Ammonia 1,200 t/day Turnkey Fertilizer Co. Egypt

2006 Egyptian Fertilizer Ain Sukhna / Suez, Ammonia 1,200 t/day Turnkey Co.(EFCII) Egypt

2006 Alexandria Fertilizers Co. Alexandria, Ammonia 1,200 t/day Turnkey (AlexFert) Egypt

2006 SaudiArabianFertilizer AlJubail, Ammonia 3,300t/day Turnkey Company(SAFCOIV) SaudiArabia

2004 Turkmendokunhimiya Tecen, Ammonia 600 t/day E,P via Gap Insaat Turkmenistan

2004 Qatar Fertilizer Mesaieed, Ammonia 2,000 t/day Turnkey Company(QAFCOIV) Qatar

2003 ASEANBintuluFertilizer Bintulu, Ammonia 1,350t/day E 3rdExpansion SdnBhd(ABF) Malaysia Expansionby 30t/day

2000 Egyptian Fertilizer Co. Ain Sukhna / Suez, Ammonia 1,200 t/day Turnkey (EFC) Egypt

1999 IstanbulGübre Körfez, Ammonia 1,200t/day E,P Expansion SanayiiA.S.(IGSAS) Turkey Expansionby 50t/day

1998 AbuQirFertilizersand AbuQir, Ammonia 1,200t/day Turnkey ChemicalInd.(AFC) Egypt (AbuQirIII)

1997 ASEANBintuluFertilizer Bintulu, Ammonia 1,320t/day E,P 2ndExpansion SdnBhd(ABF) Malaysia Expansionby 120t/day

1997 Saskferco Products Inc. Belle Plaine, Ammonia 1,800 t/day E Expansion Canada Expansionby 300t/day

1997 SASTECH(Pty)Ltd. Sasolburg, Ammonia 830t/day E Expansion SouthAfrica Expansionby 100t/day

1997 Qatar Fertilizer Mesaieed, Ammonia 1,500 t/day Turnkey Company(QAFCO3) Qatar

E Engineering

P Procurement

C Construction

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Industrial SolutionsFertilizer and Syngas Technologies

thyssenkrupp Industrial Solutions AG Friedrich-Uhde-Straße 15 44141 Dortmund GermanyP: +49 231 547 0 F: +49 231 547 10 www.thyssenkrupp-industrial-solutions.com

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