12[1][1].02 Thermodynamics and HYSYS.doc

8/13/2019 12[1][1].02 Thermodynamics and HYSYS.doc

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ThermodynamicsandHYSYS 1

ThermodynamicsandHYSYS

2000AEATechnologyplc-AllRightsReserved.Chem2_5.pdf 1


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2 ThermodynamicsandHYSYS

WorkshopOneoftheminssetsof!"#"#isitsstrongthermodynmic

fo$ndtion.%otonlycnyo$$se&idevrietyofinternlproperty

pc'ges(yo$cn$set)$lrcp)ilitiestooverridespecificproperty

clc$ltionsformorecc$rcyovernrro&rnge.Or(yo$cn$sethe

f$nctionlityprovidedthro$ghO*Etointerct&ithe+ternlly

constr$ctedpropertypc'ges.

The)$ilt-inpropertypc'gesin!"#"#providecc$rte

thermodynmic(physiclndtrnsportpropertypredictionsfor

hydrocr)on(non-hydrocr)on(petrochemiclndchemiclfl$ids.

Thedt)seconsistsofne+cessof,500componentsndover,000

fitted)inrycoefficients.f li)rrycomponentcnnot)efo$nd

&ithinthedt)se(comprehensiveselectionofestimtionmethods

isvil)leforcretingf$lly definedhypotheticlcomponents.

!"#"#lsocontinsregressionpc'ge&ithinthet)$lrfet$re.

E+perimentlp$recomponentdt(&hich!"#"#providesforover

,000components(cn)e$sedsinp$ttotheregressionpc'ge.

Alterntively(yo$cns$pplementthee+istingdtors$pplysetof

yo$ro&ndt.Theregressionpc'ge&ill fittheinp$tdttooneof

then$mero$smthemticle+pressionsvil)lein!"#"#.This&ill

llo&yo$too)tinsim$ltionres$ltsforspecificthermophysicl

propertiesthtcloselymtchyo$re+perimentl dt.

!o&ever( thererecses&hen theprmetersclc$lted)y!"#"#

re notcc$rteeno$gh(orcses&henthemodels$sed)y!"#"#do

notpredictthecorrect)ehvio$rofsomeli/$id-li/$idmi+t$res

01eotropicmi+t$res.3orthosecsesitisrecommendedto$se

notherof!yprotech4sprod$cts(#T*.Thispo&erf$lsim$ltion

progrmprovidesnenvironmentfore+plortionofthermodynmic

model)ehvio$r(properdetermintionndt$ningofinterction

prmetersndphysiclproperties(s&ellslterntivedesignsfor

distilltionsystems.

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6roper$seofthermodynmicpropertypc'geprmetersis'eyto

s$ccessf$lly sim$ltingnychemiclprocess.Effectsofpress$rend

tempert$recndrsticllylterthecc$rcyofsim$ltiongiven

missingprmetersorprmetersfittedfordifferentconditions.

!"#"#is$serfriendly)yllo&ing/$ic'vie&ingndchngingofthe

prtic$lrprmetersssocited&ithnyofthepropertypc'ges.n

ddition(yo$re)leto/$ic'lychec'theres$ltsofonesetof

prmetersndcomprethoseres$lts&ithnotherset.

nthismod$le(yo$&ill e+plorethethermodynmicpc'gesof!"#"#

ndtheproper$seoftheirthermodynmicprmeters.

LearningObjectivesOnceyo$hvecompletedthismod$le(yo$&ill)e)leto7

SelectanappropriatePropertyPackage

UnderstandthevalidityofeachActivityModel

Enternewinteractionparametersforapropertypackage

Checkmltiphase!ehaviorofastream

Understandtheimportanceofproperlyregressed!inarycoefficients

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SelectingPropertyPackagesThepropertypc'gesvil)lein!"#"#llo&yo$topredict

propertiesofmi+t$resrngingfrom&ell definedlighthydrocr)on

systemstocomple+oilmi+t$resndhighlynon-idel non-electrolytic

chemiclsystems.!"#"#providesenhncede/$tionsofstte6R

nd6R#8forrigoro$stretmentofhydrocr)onsystems9semi-

empiricl ndvpo$rpress$remodelsforthehevierhydrocr)on

systems9stemcorreltionsforcc$rtestempropertypredictions9

ndctivitycoefficientmodelsforchemiclsystems.Allofthese

e/$tionshvetheiro&ninherentlimittionsndyo$reenco$rged

to)ecomemorefmilir&iththepplictionofeche/$tion.

Thefollo&ingt)lelistssometypicl systemsndrecommendedcorreltions7

Typeof#ystem Recommended6roperty6c'ge

TE: ehydrtion 6R

#o$r;ter 6R(#o$r6R

Cryogenic:s6rocessing 6R(6R#8

Air#eprtion 6R(6R#8

AtmCr$deTo&ers 6R(6R Options(:#

8c$$mTo&ers 6R(6R Options(:#,0(

Esso>

EthyleneTo&ers *ee>esler6loc'er

!igh!2#ystems 6R(?@or:#seeTA6limits

Reservoir#ystems 6R(6R Options

#tem#ystems #tem6c'ge(C#or:#

!ydrtenhi)ition 6R

Chemicl#ystems ActivityBodels(6R#8

!3Al'yltion 6R#8(%RT*Contct!yprotech

TE:ehydrtion&ith

Aromtics

6RContct!yprotech

#


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E$ationsofState3oroil(gsndpetrochemiclpplictions(the6eng-Ro)insonEO#

6Risgenerllytherecommendedpropertypc'ge.!"#"#c$rrently

offerstheenhnced6eng-Ro)inson6Rnd#ove-Redlich->&ong

#R>e/$tionsofstte.nddition(!"#"#offersseverlmethods

&hichremodifictionsofthesepropertypc'ges(incl$ding6R#8(

?$d'evitch@offee?@nd>)dinner>.*ee>esler6loc'er

*>6isndpttionofthe*ee>eslere/$tionsformi+t$res(&hich

itself&smodifiedfromthe=;Re/$tion.Ofthese(the6eng-

Ro)insone/$tionofsttes$pportsthe&idestrngeofoperting

conditionsndthegretestvrietyofsystems.The6eng-Ro)insonnd

#ove-Redlich->&onge/$tionsofstteEO#genertellre/$ired

e/$ili)ri$mndthermodynmicpropertiesdirectly.Altho$ghtheformsoftheseEO#methodsrecommon&ithothercommercil

sim$ltors(theyhve)eensignificntlyenhnced)y!yprotechto

e+tendtheirrngeofpplic)ility.

%hePeng&'o!insonpropertypackageoptionsarePR(SourPR(andPRSV)

Soave&'edlich&*wonge$ationofstateoptionsaretheSRK(SourSRK(KDandZJ)

3ortheChemiclind$stryd$etothecommonocc$rrenceofhighly

non-idelsystems(the6R#8EO#my)econsidered.tist&o-fold

modifictionofthe6Re/$tionofsttethte+tendsthepplictionof

theoriginl6Rmethodforhighlynon-idelsystems.

+thasshowntomatchvaporpressrecrvesofprecomponentsandmi,tres(especiallyatlowvaporpressres)

+thas!eensccessfllye,tendedtohandlenon&idealsystemsgivingresltsasgoodasthoseo!tained!yactivitymodels)

Alimitedamontofnon&hydrocar!oninteractionparametersareavaila!le)

ActivityModels

Altho$ghe/$tionofsttemodelshveprovento)everyreli)lein

predictingpropertiesofmosthydrocr)on)sedfl$idsoverlrge

rngeofopertingconditions(theirpplictionhs)eenlimitedtoprimrily non-polr or slightlypolr components. 6olr or non-

idel chemiclsystemshve trditionlly)eenhndled$singd$l

model pproches.

ActivityBodelsrem$chmoreempiriclinnt$re&hencompredto

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thepropertypredictionsinthehydrocr)onind$stry.3ore+mple(

theycnnot)e$sedsreli)lysthee/$tionsofstteforgenerli1ed

pplictionore+trpoltinginto$ntestedopertingconditions.Their

t$ningprmeterssho$ld)efittedginstrepresenttivesmpleof

e+perimentldtndtheirpplictionsho$ld)elimitedtomoderte

press$res.

3oreverycomponentiinthemi+t$re(theconditionof

thermodynmicse/$ili)ri$misgiven)ythee/$lity)et&eenthe

f$gcitiesoftheli/$idphsendvpo$rphse.Thisfet$regivesthe

fle+i)ilityto$seseprtethermodynmicmodelsfortheli/$idndgs

phses(sothef$gcitiesforechphsehvedifferentforms.nthis

pproch7

ane$ationofstateissedforpredictingthevaporfgacitycoefficients.normallyidealgasassmptionorthe'edlich*wong(Peng&'o!insonorS'*e$ationsofstate(althogha/iriale$ationofstateisavaila!leforspecificapplications0

anactivitycoefficientmodelissedfortheli$idphase)

Altho$ghthereisconsider)lereserch)eingcond$ctedtoe+tend

e/$tionofsttepplictionsintothechemicl ind$strye.g.(6R#8

e/$tion(thestteofthertofpropertypredictionsforchemicl

systemsisstill governedminly)yActivityBodels.

ActivityModelsproducethebestresultswhentheyareappliedintheoperatingregionforwhichtheinteractionparameterswereregressed.

Activitycoefficientsref$dgeDfctorsppliedtotheidelsol$tion

hypothesisRo$lt4s*&initssimplestformtollo&thedevelopment

ofmodels&hichct$llyrepresentreldt.Altho$ghtheyref$dgeDfctors(ctivitycoefficientshvene+ctthermodynmicmenings

thertioofthef$gcitycoefficientofcomponentinmi+t$ret6nd

T(ndthef$gcitycoefficientofthep$recomponenttthesme6nd

T.Consequently,morecautionshouldbeexercisedwhenselectingthese

modelsforyoursimulation.


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ThermodynamicsandHYSYS

Thefollo&ingt)le)rieflys$mmri1esrecommendedctivity

coefficientmodelsfordifferentpplictionsrefertothe)$lleted

referenceg$ide)elo&7

Appliction Brg$les vn*r ;ilson %RT* %FAC

=inry#ystems A A A A A

B$lticomponent

#ystems

*A *A A A A

A1eotropic#ystems A A A A A

*i/$id-*i/$id

E/$ili)ri

A A %AA A A

il$te#ystems G G A A A

#elf-Associting

#ystems

G G A A A

6olymers %A %A %A %A A

E+trpoltion G G : : :

!2Applica!le "#!23otApplica!le $24estiona!le %25ood &!26imitedApplication

7


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' ThermodynamicsandHYSYS

8verviewofModels

Margles

Oneoftheerliestctivitycoefficiente+pressions&sproposed)y

Brg$lesttheendofthe,Hthcent$ry.

%heMarglese$ationwasthefirst5i!!se,cessenergyrepresentationdeveloped)

%hee$ationdoesnothaveanytheoretical!asis(!tisseflfor$ickestimatesanddatainterpolation)

+nitssimplestform(ithas9stonead9sta!leparameterandcanrepresentmi,treswhichfeatresymmetricactivitycoefficientcrves)

TheMargulesequationshouldnotbeusedforextrapolationbeyondtherangeoverwhichtheenergyparameters havebeenfitted.

ThevanLaarequationperformspoorlyfordilutesystemsandCA!Trepresentmanycommonsystems,suchasalcohol"hydrocarbonmixtures, withacceptableaccuracy.

!"#"#hsne+tendedm$lticomponentBrg$lese/$tion&ith$pto

fo$rdI$st)leprmetersper)inry.Thefo$rdI$st)leprmeters

fortheBrg$lese/$tionin!"#"#retheiIndIitempert$re

independentndthe)iInd)Iitermstempert$redependent.

%hee$ationwillseparametervalesstoredin:;S;Soranysersppliedvaleforfrtherfittingthee$ationtoagivensetofdata)

+n:;S;S(thee$ationisempiricallye,tendedandthereforecationshold!ee,ercisedwhenhandlingmlticomponentmi,tres)

van6aar

The vn *r e/$tion &s the first :i))s e+cess energy

representtion &ithphysicl significnce. This e/$tion fits mny

systems /$ite &ell( prtic$lrly for **E component distri)$tions. t

cn)e$sedfor

systemsthte+hi)itpositiveornegtivedevitionsfromRo$lt4s*&.

#omeofthedvntgesnddisdvntgeforthismodel re7

5enerallyre$ireslessCPUtimethanotheractivitymodels)

+tcanrepresentlimitedmisci!ilityaswellasthreephasee$ili!rim)

+tcannotpredictma,imaorminimaintheactivitycoefficient

andtherefore(generallyperformspoorlyforsystemswithhalogenatedhydrocar!onsandalcohols)

+talsohasatendencytopredicttwoli$idphaseswhentheydonote,ist)


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ThermodynamicsandHYSYS (

Thevn*re/$tionimplementedin!"#"#hst&oprmeters&ith

linertempert$redependency(th$sm'ingitfo$rprmeter

model.n!"#"#( thee/$tionisempiricllye+tendedndthereforeits

$sesho$ld)evoided&henhndlingm$lticomponentmi+t$res.

=ilson

The;ilsone/$tion(proposed)y:rntB.;ilsonin,HJ(&sthe

firstctivitycoefficiente/$tiontht$sedtheloclcompositionmodel

toderivethe:i))sE+cessenergye+pression.toffers

thermodynmicllyconsistentpprochtopredictingm$lti-

component)ehvio$rfromregressed)inrye/$ili)ri$mdt.

The #ilson equationCA!T be used forproblems involving liquid"liquidequilibrium.

The additionalparameterinthe$TLequation,calledthealphaterm,ornon"randomnessparameter,

representsthe inverseofthecoordinationnumberofmolecule%i&surroundedbymolecules%'&.(ince liquidsusuallyhaveacoordinationnumberbetween)and*,youmightexpectthe alphaparameterbetween+.-and+.)).

Althoghthe=ilsone$ationismorecomple,andre$iresmoreCPUtimethaneitherthevan6aarorMarglese$ations(itcanrepresentalmostallnon&idealli$idsoltionssatisfactorilye,ceptelectrolytesandsoltionse,hi!itinglimitedmisci!ility.66Eor/66E0)

+tperformsane,cellent9o!ofpredictingternarye$ili!rimsingparametersregressedfrom!inarydataonly)

+twillgivesimilarresltstotheMarglesandvan6aare$ationsforweaknon&idealsystems(!tconsistentlyotperformsthemforincreasinglynon&idealsystems)

+tcannotpredictli$id&li$idphasesplittingandthereforesholdonly!esedonpro!lemswheredemi,ingisnotanisse)

O$re+periencesho&sthtthe;ilsone/$tioncn)ee+trpolted

&ith reson)le confidence to other operting regions &ith the

sme setofregressedenergyprmeters.

3'%6

The%RT*%on-Rndom-T&o-*i/$ide/$tion(proposed)yRenon

nd6r$snit1in,HK(isne+tensionoftheoriginl ;ilsone/$tion.t

$sessttisticlmechnicsndtheli/$idcell theorytorepresentthe

li/$idstr$ct$re.Theseconcepts(com)ined&ith;ilson4slocl

compositionmodel(prod$cene/$tioncp)leofrepresenting8*E(

**E(nd8**Ephse)ehvio$r.*i'ethe;ilsone/$tion(the%RT*

model isthermodynmiclly consistentndcn)eppliedtoternry

ndhigherordersystems$singprmetersregressedfrom)inrye/$ili)ri$mdt.The%RT*model hsncc$rcycompr)letothe

;ilsone/$tionfor8*Esystems.

%he3'%6com!inestheadvantagesofthe=ilsonandvan6aare$ations)

>


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1) ThermodynamicsandHYSYS

+tisnote,tremelyCPUintensive)

+tcanrepresent66E$itewell)

:owever(!ecaseofthemathematicalstrctreofthe3'%6e$ation(itcanprodceerroneosmltiplemisci!ilitygaps)

The%RT*e/$tionin!"#"#continsfivedI$st)leprmeters

0tempert$redependentndindependentforfittingper)inrypir.

U3+4UAC

The%FAC%verslFAsiChemicle/$tionproposed)y

A)rmsnd6r$snit1in,HL5$sessttisticlmechnicsndthe/$si-

chemicl theoryof:$ggenheimtorepresenttheli/$idstr$ct$re.The

e/$tioniscp)leofrepresenting**E(8*End8**E&ithcc$rcycompr)letothe%RT*e/$tion()$t&itho$ttheneedfornon-

rndomnessfctor(itist&oprmetermodel.

The%FACe/$tionissignificntlymoredetilednd

sophistictedthnnyoftheotherctivitymodels.

+tsmainadvantageisthatagoodrepresentationof!oth/6Eand66Ecan!eo!tainedforalargerangeofnon&electrolytemi,tressingonlytwoad9sta!leparametersper!inary)

%hefittedparameterssallye,hi!itasmallertemperatredependencewhichmakesthemmorevalidfore,trapolationprposes)

%heU3+4UACe$ationtili?estheconceptoflocal

compositionasproposed!y=ilson)Sincetheprimaryconcentrationvaria!leisasrfacefractionasopposedtoamolefraction(itisapplica!letosystemscontainingmoleclesofverydifferentsi?esandshape(schaspolymersoltions)

%heU3+4UACe$ationcan!eappliedtoawiderangeofmi,trescontaining:28(alcohols(nitriles(amines(esters(ketones(aldehydes(halogenatedhydrocar!onsandhydrocar!ons)

n its simplest form it is t&oprmeter model( &ith the sme

remr's s;ilson nd%RT*.%FACneeds vnder;ls re

ndvol$meprmeters(ndthosecnsometimes)ediffic$lttofind(

especilly for non-condens)le gses ltho$gh 66R hs fir

n$m)ervil)le.

E,tendedand5eneral3'%6

TheE+tendednd:enerl%RT*modelsrevritionsofthe%RT*

model(simple%RT*&ithcomple+tempert$redependencyforthe

iIndIiterms.Applyeithermodel tosystems7

1@


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The general$TLmodel isparticularly susceptible toinaccuracies if the model isusedoutsideofthe intendedrange.

Care mustbetaentoensurethatyouare operatingwithintheboundsofthemodel.

ointeractionbetween/non"condensable/componentpairsista.enintoaccountinthe 0L1calculations.

withawide!oilingpointrange!etweencomponents

whereyore$iresimltaneossoltionof/6Eand66E(andtheree,istsawide!oilingrangeorconcentrationrange!etweencomponents

E+tremec$tionm$st)ee+ercised&hene+trpolting)eyondthe

tempert$rendpress$rernges$sedinregressionofprmeters.5$e

tothelrgern$m)erofprmeters$sedinfitting(incc$rteres$lts

cn)eo)tinedo$tsidetheoriginl)o$nds.

Chien&3ll

Chien-%$ll isnempiriclmodeldesignedtollo&yo$tomi+nd

mtchmodels&hich&erecreted$singdifferentmethodsnd

com)inedintom$lticomponente+pression.TheChien-%$llmodel

providesconsistentfrme&or'forpplyinge+istingctivitymodels

on)inry)y)inry)sis.nthismnner(Chien-%$ll llo&syo$to

selectthe)estctivitymodel forechpirinthecse.3ore+mple(

Chien-%$ll cnllo&the$sertohve)inrydefined$sing%RT*(

nother$singBrg$lesndnother$singvn*r(ndcom)inethem

toperformthreecomponentclc$ltion(mi+ingthreedifferent

thermodynmicmodels.

TheChien%$llmodelllo&sMsetsofcoefficientsforechcomponent

pir(ccessi)levitheA(=ndCcoefficientmtrices.

providesmoreinformtionon6roperty6c'ges(E/$tionsof#tte(ndActivity Bodels(ndthee/$tionsforech.

:enrys6aw

!enry4s*&cnnot)eselectede+plicitlyspropertymethodin

!"#"#.!o&ever(!"#"#&ill $se!enry4s*&&hennctivitymodel is

selectedndNnon-condens)leNcomponentsreincl$ded&ithinthe

componentlist.

!"#"#considersthefollo&ingcomponentsnon-condens)le7

Bethne(Ethne(Ethylene(Acetylene(!ydrogen(!eli$m(Argon(

%itrogen(O+ygen(%O(!2#( CO2(ndCO.

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Thee+tended!enry4s*&e/$tionin!"#"#is$sedtomodeldil$te

sol$teAsolventinterctions.N%on-condens)leNcomponentsre

definedsthosecomponentsththvecriticltempert$res)elo&the

systemtempert$re.

ActivityModel/aporPhase8ptions

Therereseverlmethodsvil)leforclc$ltingthe8po$r6hsein

conI$nction&iththeselectedli/$idctivitymodel.Thechoice&ill

dependonspecificconsidertionsofyo$rsystem.

+deal

Theidel gsl&cn)e$sedtomodel thevpo$rphse.Thismodel is

ppropriteforlo&press$resndforvpo$rphse&ithlittle

intermolec$lrinterction.Themodel isthedef$ltvpo$rphse

f$gcityclc$ltionmethodforctivitycoefficientmodels.

Peng'o!inson(S'*or'*

Tomodelnon-idelitiesinthevpo$rphse(the6R(#R>(orR>

optionscn)e$sedinconI$nction&ithnctivitymodel.

PRandSRKvaporphasemodelshandlethesametypesofsitationsasthePRandSRKe$ationsofstate)

=henselectingoneofthesethreemodels(ensrethatthe!inaryinteractionparameterssedfortheactivitymodelremainapplica!lewiththechosenvapormodel)

Borapplicationswithcompressorsandtr!ines(PRorSRKwill!esperiortotheRKor+dealvapormodel)

/irial

Careshouldbeexercisedinchoosing2$,($3,$0or0irialtoensure binarycoefficientshave beenregressedwiththecorrespondingvapourphasemodel.

The8iriloptionen)lesyo$to)ettermodelvpo$rphsef$gcities

ofsystemsdisplyingstrongvpo$rphseinterctions.Typiclly this

occ$rsinsystemscontiningcr)o+yliccids(orcompo$ndsththve

thetendencytoformst)le!2)ondsinthevpo$rphse.

!"#"#continstempert$redependentcoefficientsforcr)o+yliccids."o$cnover&ritethese)ychngingtheAssocitioniIor

#olvtioniicoefficientsfromthedef$ltvl$es.

Thisoptionisrestrictedtosystems&herethedensityismoderte(

typicllylessthnone-hlfthecriticldensity.

12


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Thenumbersappearinginthematrixareinitiallycalculatedby45(5(, butyouhavetheoptionofoverwritinganylibraryvalue.

inaryCoefficients3orthe6roperty6c'ges&hichdoincl$de)inrycoefficients(the

=inryCoefficientst)continsmtri+&hichliststheinterction

prmetersforechcomponentpir.5ependingontheproperty

methodchosen(differentestimtionmethodsmy)evil)lend

differentvie&my)esho&n."o$hvetheoptionofover&ritingny

li)rryvl$e.

E$ationofState+nteractionParameters

TheE/$tionof#ttenterction6rmetersgro$ppperssfollo&s

onthe=inryCoeffst)&hennEO#istheselectedpropertypc'ge7

3orllEO#prmeterse+cept6R#8(

3i'63'i

so&henyo$chngethevl$eofoneofthese()othcellsofthepir

$tomticlly$pdte&iththesmevl$e.nmnycses(theli)rry

interctionprmetersfor6R#8dohve3i'63'i()$t!"#"#doesnot

forcethisifyo$modifyoneprmeterin)inrypir.

1"


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f yo$re$sing6Ror#R>oroneofthe#o$roptions(t&ordio

)$ttonsredisplyedtthe)ottomofthepgeintheTretmentof

nterctionCoefficientsnvil)lefromthe*i)rrygro$p7

*s+ima+eH,-H,#Se+"onH,-H,+o).)Dthisradio!ttonisthedefaltselection):;S;Sprovidestheestimatesfortheinteractionparametersinthematri,(settingallnon&hydrocar!onpairsto@)

Se+!//+o).)Dwhenthisisselected(:;S;Ssetsallinteractionparametervalesinthematri,to@)@)

ActivityModel+nteractionParameters

ActivityBodelsrem$chmoreempiriclinnt$re&hencompredto

thepropertypredictionsinthehydrocr)onind$stry.Theirt$ning

prmeterssho$ld)efittedginstrepresenttivesmpleof

e+perimentldtndtheirpplictionsho$ld)elimitedtomoderte

press$res.

TheActivityBodelnterction6rmetersgro$ppperssfollo&s

onthe=inryCoeffst)&hennActivityBodelistheselected

propertypc'ge7

Theinterctionprmetersforech)inrypir&ill)edisplyed."o$

cnover&ritenyvl$eor$seoneoftheestimtionmethods.

%otethtthe3i'63'ir$ledoesnotpplytoActivityBodel interction

prmeters.

1#


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EstimationMethods

;hen$singActivityBodels(!"#"#providesthreeinterction

prmeterestimtionmethods.#electtheestimtionmethod)y

choosingoneoftherdio)$ttonsintheCoeffEstimtion&indo&.The

optionsre7

U3+BAC/6E

U3+BAC66E

+mmisci!le

"o$cntheninvo'etheestimtion)yselectingoneofthevil)le

cells.

3or%3ACmethodstheoptionsre7

0ndiidua/PairDcalclatestheparametersfortheselectedcomponentpair(Ai9 andA9i)%hee,istingvalesinthematri,areoverwritten)

nnons n/yDcalclates theactivityparameters forallthe nknown pairs) +f yo delete the contents of cells or if:;S;S does not provide defalt vales( yo can se thisoption)

!//inariesDrecalclatesallthe!inariesofthematri,)+fyohadchangedsomeoftheoriginal:;S;Svales(yocoldsethistohave:;S;Sre&estimatetheentirematri,)

.

ret$rntheoriginlli)rry vl$es.Estimtionvl$es&ill)eret$rned$singtheselected%3ACmethod.Toret$rntotheoriginlli)rry vl$es(yo$m$stselectne&propertymethodndthenre-selecttheoriginlpropertymethod

The 89:AC;89quacgroup":unctionalActivityCoefficient


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=hichActivityCoefficientModelShold+Use

Thisisto$gh/$estiontons&er()$tsomeg$idelinesreprovided.f

yo$re/$iredditionl ssistnce(itis)esttocontct!yprotech4s

Technicl#$pportdeprtment.

asicFata

Activitycoefficientmodelsreempiricl)ynt$rendthe/$lityof

theirpredictiondependsonthe/$lityndrngeofdt$sedto

determinetheprmeters.#omeimportntthingsyo$sho$ld)e&re

ofin!"#"#.

%heparameters!iltin:;S;Swerefittedat1atmwhereverpossi!le(orwerefittedsingisothermaldatawhichwoldprodcepressresclosestto1atm)%heyaregoodforafirstdesign(!talwayslookfore,perimentaldataclosertotheregionyoareworkingintoconfirmyorreslts)

%hevalesinthe:;S;Scomponentdata!asearedefinedfor/6Eonly(hencethe66Epredictionmaynot!everygoodandadditionalfittingisnecessary)

Fatasedinthedeterminationof!iltininteractionparametersveryrarelygoes!elow@)@1molefraction(ande,trapolatingintotheppmorpp!regioncan!erisky)

Again(!ecasetheinteractionparameterswerecalclatedatmodestpressres(sally1atm(theymay!einade$ateforprocessesathighpressres)

Checktheaccracyofthemodelfora?eotropicsystems)Additionalfittingmay!ere$iredtomatchthea?eotropewithaccepta!leaccracy)Checknotonlyforthetemperatre(!tforthecompositionaswell)

+fthreephase!ehaviorissspected(additionalfittingoftheparametersmay!ere$iredtorelia!lyreprodcethe/66Ee$ili!rimconditions)

U3+BACornoU3+BAC

%3ACishndytool togiveinitilestimtesforctivitycoefficient

models.%evertheless'eepinmindthefollo&ing7

5ropcontri!tionmethodsarealwaysappro,imateandtheyarenots!stittionsfore,perimentaldata)

U3+BACwasdesignedsingrelativelylowmoleclarweightcondensa!lecomponents.thshigh!oilersmaynot!ewellrepresented0(singtemperatres!etween@&1-@oCanddataatmodestpressres)

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5enerally(U3+BACdoesnotprovidegoodpredictionsforthedilteregion)

ChoosinganActivityModel

Agin(somegenerl g$idelinestoconsider.

8ar9u/esoran&aar&generallychosenifcomptationspeedisaconsideration)=iththecompterswehavetoday(thisissallynotanisse)Mayalso!echosenifsomepreliminaryworkhas!eendonesingoneofthesemodels)

:i/son&generallychosenifthesystemdoesnote,hi!itphasesplitting)

"RT&or"0;!,&generallychosenifthesysteme,hi!itsphasesplitting)

%enera/"RT&&sholdonly!esedifana!ndantamontofdataoverawidetemperatrerangewassedtodefineitsparameters)8therwiseitwillprovidethesamemodellingpoweras3'%6)

ExploringwiththeSimlation6roper$seofthermodynmicpropertypc'geprmetersis'eyto

s$ccessf$lly sim$ltingnychemiclprocess.Effectsofpress$rendtempert$recndrsticllylterthecc$rcyofsim$ltiongiven

missingprmetersorprmetersfittedfordifferentconditions.

!"#"#is$serfriendlyinllo&ing/$ic'vie&ingndchngingofthe

prtic$lrprmetersssocited&ithnyofthepropertypc'ges.

Additionlly(the$seris)leto/$ic'lychec'theres$ltsofonesetof

prmetersndcompreginstnother.

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1' ThermodynamicsandHYSYS

E,ercise1

Fi&iso&Propyl&EtherG:28inary

Thise+mpleeffectivelydemonstrtestheneedforhvinginterction

prmeters.othefollo&ing7

,. Opencse6E.hsc.

2. Enterthefollo&ingconditionsforstrem6EA!2O7

Conditions

8po$r3rction 0.0

6ress$re ,tm

Bolr3lo& ,'gmoleAh,l)moleAhr

Composition

di-i-6-Ether 50mole

!2O 50mole

#hatphasesarepresent>??????????

M. Closethestremvie&ndpressthe1nter7asis1nvironment)$tton.

J. #electthe=inryCoeffst)ofthe3l$id6c'ge.%oticethttheinterctionprmetersforthe)inryre)othsetto0.0.

5. 6ressthe$eset2arams)$ttontorecll thedef$lt%RT*ctivity

coefficientmodelinterctionprmeters.

. Closethe3l$id6c'gevie&.

L. Ret$rntothesim$ltionenvironment)ypressingthe$eturnto

(imulation1nvironment)$tton.

K. Openthestremvie&)ydo$)leclic'ingonthestrem6EA

!2O.

#hatphasesarenowpresent>??????????

#hatisthecompositionofeach>??????????

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ThermodynamicsandHYSYS 1(

Clerly(itcn)eseenho&importntitistohveinterction

prmetersforthethermodynmicmodel.The+yphsedigrmson

thene+tpgefig$res,nd2ill$strtethehomogeneo$s)ehvio$r

&hennoprmetersrevil)lendtheheterogeneo$s1eotropic

)ehvio$r&henproperlyfittedprmetersre$sed.ThemIorityof

thedef$ltinterctionprmetersforctivitycoefficientmodelsin

!"#"#hve)eenregressed)sedon8*EdtfromEC!EBA(

Chemistryt#ervices.

1>


20/26

2) ThermodynamicsandHYSYS

3ig.,-nterction6rmeterssetto0.

3ig.2-singtheef$lt!"#"#nterction6rmeters.

2@


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E,ercise2

PhenolG:28inary

This)inrysho&stheimportnceofens$ringthtproperlyfitted

interctionprmetersfortheconditionsofyo$rsim$ltionre$sed.

Thedef$ltprmetersforthe6henolA!2Osystemhve)een

regressedfromtheEC!EBAChemistrydtseriesndprovidevery

cc$rtevpo$r-li/$ide/$ili)ri$msincetheoriginldtso$rce,

&sinthisformt.!o&ever(the6henolA;tersystemislsosho&nto

e+hi)itli/$id-li/$id)ehvio$r2.Asetofinterctionprmeterscn

)eo)tinedfromso$rcess$chsEC!EBAndenteredinto!"#"#.

Thefollo&inge+mpleill$strtesthepoor**Epredictionthncn)e

prod$ced)ycompringtheres$lts$singdef$ltinterction

prmetersndspecillyregressed**Eprmeters.

,. Openthecse6henolh2o.hsc.

2. Enterthefollo&ingconditionsforstrem6henolA!2O7

Conditions

Tempert$re J0PC

6ress$re ,tm

Bolr3lo& ,'gmoleAh,l)moleAhr

Composition

6henol 25mole

!2O L5mole

#hatphase;s??????????

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Toprovide)etterpredictionfor**EtJ0oC,05o3thefollo&ingAiI

interctionprmetersreto)eentered.Toentertheprmetersdo

thefollo&ing7

,. Closethestremvie&ndpressthe1nter7asis1nvironment)$tton.

2. Ens$rethe3l$id6c'gevie&isopenndselectthe=inry

Coeffst).

M. EntertheAiIinterctionprmetersssho&nhere7

J. #electtheAlphai'@Ci'rdio)$tton.

5. EnternAlphiIQ0.2.


L. Ret$rntothesim$ltionenvironment)ypressingthe$eturnto

(imulation1nvironment)$tton.

K. Openthestremvie&for6henolA!2O.

#hatphase;s??????????

#hatarethecompositions>??????????

Thefig$resonthefollo&ingpgefig$resMndJsho&thedifference

)et&eenthet&osetsofinterctionprmeters.Therefore(crem$st)e

e+ercised&hensim$lting**Eslmostllthedef$ltinterctionprmetersforthectivitycoefficientmodelsin!"#"#refor8*E.

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3ig.M-singtheef$lt8*Enterction6rmeters.

3ig.J-singthe3itted**EOptimi1iednterction6rmeters.

2"


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E,ercise"

en?eneGCyclohe,aneG:28%ernary

This e+mple gin ill$strtes the importnce of hving

interctionprmetersndlsodisc$ssesho&the$sercno)tin

prmeters from regression. To ill$strte theprinciples do the

follo&ing7

,. OpenthecseTernry.hsc.

2. Enterthefollo&ingstremconditionsfor=en1eneACCA!2O7

Conditions

Tempert$re 25PC

6ress$re ,tm

Composition

=en1ene 20mole

!2O 20mole

CC 0mole

4owmanyphasesarepresent>??????????

Toprovidemoreprecisesim$ltionthemissingCCA!2Ointerction

prmeterhsto)eo)tined.3ort$ntely(somedtisvil)let

25PCgivingtheli/$id-li/$ide/$ili)ri$m)et&eenCCnd!2O.sing

thisdt(ndtheregressioncp)ilities&ithin#T*(nAEA

TechnologyEngineering#oft&reconcept$ldesignnd

thermodynmicregressionprod$ct(yo$cno)tinne&interction

prmeters.Thetempert$redependent=iIprmetersreto)eleftt

0ndthelphiItermisto)esetto0.2fortheCC!2O.Toimplement

theseprmeters(proceed&iththestepsonthefollo&ingpge.

2#


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,. Ret$rntothe=sisEnvironment)ypressingthe1nter7asis1nvironment)$tton.

2. Openthe3l$id6c'gevie&ndmovetothe=inryCoeffst).

M. EnterthedtintheAiImtri+ssho&nhere7

J. #electtheAlphai'@Ci'rdio)$tton.

5. EnterCCA!2OlphiIvl$eof0.2.


L. Ret$rntothe#im$ltionEnvironment.

K. Openthestrem=en1eneACCA

!2O.

4owmanyphasesarenowpresent>??????????

#hatarethecompositions>??????????

Thefig$resonthefollo&ingpgefig$res5ndclerlysho&the

)ehvio$roftheternrysystem.;itho$ttheregressedCCA!2O

)inry(thethermodynmicpropertypc'geincorrectlypredictsthe

systemto)emisci)lethigherCCconcentrtions.Thispredictionis

correctgivenproperlyregressedCCA!2Oprmeters.

'eferences

,.#chreinem'ers3.A.!.(?.2hys.Chem.M5(J5H,H00.

2.!illA.E.ndBlisoff;.B.(@.Am.Chem.(oc.

JK,H2H,K.

2-


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3ig.5-;itho$tRegressedCCA!2Onterction6rmeters.

3ig.-;ithRegressedCC!2Onterction6rmeters.

2

12[1][1].02 Thermodynamics and HYSYS.doc

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