This paper presents the modelling of a Polyvinyl Chloride (PVC) resins manufacturing process with batch process simulator, SuperPro Designer V6.0. The simulation model has been developed based on the operating condition of a local PVC manufacturing plant. As the polymerisation process is carried out in batch operation mode, efforts have been made to document the scheduling details of each unit operation and results are presented in the Gantt chart. Cycle time for a complete polymerisation process is determined to be 14.28 hours. The model also reveals that approximately 17 batches of polymerisation reaction can be processed per day, which tallies the real operation of the PVC manufacturing plant

Abdul Aziz, Ramlan

Abu Hassan, Mohd. Ariffin

Chan, Jun Hoa

Foo, Dominic C. Y.

Kumaresan, Sivakumar

English

Universiti Teknologi Malaysia Institutional Repository

ICCBPE / SOMChE 2OO5NITE-20Process Modelling ofA PVC Proaluction PlantChan Jun Hoar Dominic C. Y. Foo'? Sivakumar KumaresanlRam]an Abdul Azizr Mohal Adffin Abu [Iassan3) Cheni.al EngineerinE Pilot Plant, UniversiiTeknalogi Mdlatsid8 1 3 1 4 Sktulai, lohor, MalarsiaTel: +60'7 -i 53 1662, Fax: +6a-7-556 97A6, E'moil: ]'ti[t@kop. tri ,tt: ntnltrt@ cepD utn "N1 Schaol of Cheflicdl and EnvnonnentaL Enginee n8, Uniwtsitt of NottinqhM (MdLalsiLt CMPU\)Jdian Btagd $5aA Sedenrih selahgar Darut Ehsan MatqtsiaTeI: +60-3-3921 8130, Fat: +60 3 8924'8A17, E tuail: Dottiri. l-oa@nnni'pharLetd n\3 Chehi.dl Eneineenng Dep4nnen. Uniretsiti Tekhaloei Malayia8131A Skadai, JohoL MalalliaTel: +60-7553-5485, FN: +60-7-558 1,163, E'mail: narifln@fl*kla utnfitrAbstractThis pap.r presents the modellihs of a Polrtinrl Chbn blPvC) ftsins nanuJdctarins ptucess vith batch Processsinutat r, SuperPrc DesiSner v6 0 The sihulatiot m.4.1has been dedaped bued a. the oPentiag condnion of alocdl PVC ntanuldc nns pkttt. As the PoLrme4dtionprcces b cdftied out in bdtch apetatioh nade, effons har.beeh hade to dncunent the scheduliry .tetails oJ edch unrtoperdtian abd. rcsuht are prcsented in the Gantt .harta l" .ia? to, a .ompaP Datta'tt anoh Pra.?' idetemined to be 11.28 hou^. The nodel also rcreak thdtapprcriMtel, 17 batch.s ol polJmerkatioh rcactia4 con beplocesed per .1d!, which taUies the rcaL aPelation of thePvC nan uJdctutits p lant.Keywords: ModelLing, optinisation, batch poces,scheduling, lVC poduciion.IntroductionThe Conrlurq Aided Proce$ DesiSn (CAPD) atdsimulation Lools have been widely used in the buLt andpeircchedical itdust.ies since the erly 1960's It inv.lve-s$e use oi conpute$ to pedom steady-stale h at and m$sbalancing as veu d sizjng add costing ctrcuhilons for aprocess lll. However, the use of dese CA?D udslmulatiod t@ls has only emerged in the batcbnanufact .ing in the last decade [2_7] Conpded !o thercxdily alaildle comercial process siDuiato^ in the bulkchenicai industnes, there are only a limited nunber ofcommecial simulatos available lor batch Procesmodelling in the ma.ket, wbich include Barches by BaichProces Technologies. Batch Plus by Aslen Technology,Sup€rPrc Designer by Inielli8en as weu as Batch DesigrKir by Hyprotech. This siNarion is mainly due ro rhecomplexiry assoclated witb batch Proceses tba! detequenrly operated in cyclical mode. Due to its reLativelynev emergence, nuch work needs to be done in this sector.Tbis !a!e. desc.ibes the use of tbe comeicial b.tchprocess simulator SulerPlo Designe! v6.0 t8l in thenodelljns of a locrl lndusbial production of pobnlnylchloride (PVC), which is operrred in mixed barh andPVC Manufacturing Case StudyI igu e Lhow. ,h" proce \ flow dr,gjd ot Lhe Pvc re. r\manufacluring. h consists of 10 ptuallel batcbpolymedsation rcactos, blow'down ve$el, dd twopdallel hains of downstrcam procesing equipment. Ercbdownstream proce$ing !.ail consists of a stri?per, twodecotes dd a fluid bed dryer. The phnt is op*ated ln aseml batch mode where ulsLrm rclctoF ue scheduled tonalch the dowrsr]em processing rrains lhat de operated fThe baLch reacror feed consist of a mixture of f.esh vilylchlodde monome. (VCM) md recycied vCM from theproce$, mainly f.om btowdown eesel ad s(ipper. At thepolynerlsing or rcacdon secdon of rbe pLant, thepolydensing proces i! caried out subsequently n ienparallel barch re@to!s, Rdw ddtenab ibr thepolymerisation proces include d€minemlised warer, vcM,idtiaio.s ard suspending agents. These raw matenal echarged jito the re&roi in sequerce. The pH of tnedeionised earer is kept berween 6.6 9.0. The suspeldingagent is diluted to aplroximalelr 4.0vt% ald is chrgedinro rhe reactor together vith denlneralised water. This ismrinly dde to lhe high viscosity of the suspending agentJpor .he complefon o '"u petd:ng agen. !h.rge. p, 'ma^and secondal-a lnitiatos a.e added into the reactor manLiallyvla the ve$el man hole. Mdual chugi!8 of initiator isICCBPE / SOMChE 2OO5requned 3 flucluations resuked froh the autohatedchargrng sysrer nay lead Io severe safety problem js nottolerable Two rypes of inidatos a.e us€d jn thNvcMvcMPVCpolymerisation p.ocess, with the prlndl initiltor inpowder fom while the secondary iniriab. in flat<es fom.F/8r.a / Pro. e." tloq dhgrxn ofa PV. reufnudng olMrAfter rhe chdging of watei conpletes. the reactor is prrgedby nilJogen ard then vacuumed befo.e charging of VCM ischdged. This is to ensure tbat no oxygen is pftsent in thereactor as reactior between VCM dd oxygen dd mightFsult in extlosioo.Upon ihe compledon of VCM chdge, heatins is comenceto nise the reacto. temperature to the optimal rcachontemperature of 57oC ud a workirg pessure of 8-9 bd.Exothefri. polymensddon ptuces next comnences, for aduEnon of 7.5 hours. Contiruous cooling is needed roremove excess heat ud to maintain the re@tor tempentmat 57"C. PvC polyme. is the main produd ar the end of thepolymerisdtion process. Other bl-products of the reactionale the unrcacted vcMi iniiiato$, susFndhg agenr andsome kace amount of contamindt. The reaclor conrent isdow presert in slunf fom (a mixture of PVC and watedand is ready !o besentto tbeblowdown syst.m.The blo$dowr vessel receives batches of slu!ry wbich eeinremitterrly dischdged fom rhe reactors. The blowdownlessel acts dr bdffer stonge so thar sturry cb be-ond ,uou. ly IeJ .o ,he ,wo pdal le l  doqnstfrd prcce.. in8tnins. As s1urry is discheged fronr the reelor, ldge lunpswhich could bldk downstrem equtlnent m €noled bysfiainen. As the slury enters ihe blowdown vessel. thenajor pornon of lhe unreacted vCM trapted in the PvCparticles flshes of md is vefted to the gasloldtr forrccolery. The vcM vapoor ls lext codpressed Ddcondensed into liquid lom before it is reused in thepol)merisatioD prcce$.As the effluent Aom the blowdown v€sseL entels thedoMsrrem pro.esing Lairs, lhe shlpper colum tuitrerTh€ batch reacloi feed consjst oi a ni{tue of freslt vinylchloride monome. (VCM) and recycled VCM f.on tbep.ocess, naidly fron blovdown vessel add sripper. At thepolymedsing or reaction seclion of lhe p1dr, thepolymerislng proces is caried ou! subsequertly io tenpdallel batch reacto6. Raw materials fo! thepolymensation proce$ irclude denineralised water, VCM,initiato$ dd suspendirg agenrs. Tbese raw matenal uecharged inio the reactor in se4uence. The !H of thedeiorised wate.is kept belween 6.6 - 9.0. The suspendingagent is diluted to approxinately 4.0wt7o and is chdgedinio the reacror together with denineralised water. This ismainly due to the high viscosity of fie susPending aged' I o- l e co. oleoo, ol \..p_, d -e a8Fn' ft r8e. primcr)add secondary initiatos ae added into lhe .edctor mduallyvia lhe vesel mm hole. Manuai chtuSlng of initiator isrequiEd s tlucrDadons resulted lrom the autonatedchdgins system my lead to severe safely problen is nottolefable. Two types of initialors de used in ltuspol .TFr\1non poc+i .  u,rh rLr p,ma, l  in i l inor inpowder fom while the secordary initiator in flakes fom.l ,  .  1 l \o oe ,o p,ping conJTi ldonine$riled water can only be chdged inlo the reaclosone at a lim€ Demineralised water chdgine in each reactorrekes approximatell 20 minutes !o comPlete. chargugprocedu.e in e&h of the reactor wlll only slart after the endof chdging in an eelier reactor. The sme situation occursto rhe cheging ot vCM dd the biowdown opention after882ICCBPE / SOMChE 200sremores lhe unreacted vcM from the Pvc slurry. sremis iniroduced ar the bse of the stipping colum dd theVCM is moved as a. overhead lroducr to the gdholder.The stipped slurry is then djlected to rwo p{allel decarterslbr water remolrl. Approrihately 797a of wate. is.emoved by rhese <lecante$ lrom the PVC slurryWet cake fron lbe decMtes is rcxt se to the fluidisedbed dryer ro be dried by hor an dd hor water (in tubswhjch a.e heated by stean). Direcr usage of steam m tnedryer is not pGciical as the PvC resins have a low Gla$limsitio! Temperatlre (TJ of 78'C. Exposure of PvCrsins unde. the stem of 10ffC will cause the siructw ofthe resins to collapse. This softens the PVC resins andresulh in poor qurlity of resjns.D.ied PvC rcsins are transpoded by cool pldt air to theshifter. Thc use of cool plrnt air avoids rhe e]€ctrostaticforce that may cause the resins to flocculat.. Flne .e$nsthat pdss rhroush rhe shilter (60 mesb) &e sold as productwhile the couse .esins de gnnded and sold as Low-gddeBase Case Process SimulationFlgurc 2 sbows the base case process simulation model thatbas beed develoled b6ed on the operathg conditiotr ol tbePVC nanufacturing process using Sule.Pro Designer V6.0(Inteilesen, 2005). The dnual operating tine of dePrcce$model is tak€n a5 7920 bous.ln the modelling envilonment of Supe.Pro Dsigne., a lewoperarionr rnke place sequertially ln r single d't'prccedure (.\\ret1eg.r. 2005). For instance, vesserprocednre P-l tu Fisure 2 is used ro model rhe oacrpoi)me.isai.ion pro.ess that consisr of sequeftial olentionsol .aw marerial chdges, vacuum, maleriai heatjng,polynerisation proces d well as prcduct blowdown. Autbese individual operationi rake plee in ve$et K207(wheie yessel Focedure P I takes place). The modellins ofthese single opemtiols is desc.ibed nexr.The raw material chtuged into K20? during rbe srari ofproce{lure P-] includes demitrenljsed varer (CHARGE-H2O), slspendins agent (CEARGE-PVA), prjme.yinitiator (CHARCE-CATI) Dd secondary idrialor(CHARCE-CAT2). P.operties of rhe tuw materidls used tnthe model de summdised ln Table I . Nore ihat suspendingrgent, pnmary and secondary inidaron e user definedcomponeDts where then proledies have beetr changed uthe model. Note that the model has iNluded rhe acualopendng condition of the PVC moufacturing procss,where the chtuglng otdemineElised warer for a subsequenlEactor is scheduled to srui after the warer chugjng ot tbepreceding reactor e!ds. Suspendirg agent, primary andsecondary initiatod m cheged into the reactor dudng theThe vrcum operrlions (VACWM) in prccedure P Iinciude a vacuun air purge from lhe reacto! to 0.226 ara(gauge pEssue = -0 8 kg/6') lbuowed by ! nimgen saspurge to 1.194 atm (gauge presure - 0.2 kChnl ddanothe-r vacuun porge to 0.226 atm (gauge pE$ule = 0.8kg/cn"). The vacuun operations were cdied out beforethe chdgog of VCM (CHARGEVCM). This is to avoidrr-n . inBol \ .M si .har.whch uAhr.eadroe\plonontJ.Fisutp 2 s'nLta a"llo\|.heqat PvC aonuta' t"tnc333ICCBPE / SOMChE 2OO5Tabte t - Feed Stean SpeciJicationChilled HrO 100 US gal(1135.62ks)1.7 kg MW = 571.0007kg MW=398.70Nomdl boiling point =461"CI55kg MeLdng point = 228 'CvcM10500 keln the heating operation, hot water (inlet temlerature of90'C and outlet temperature of 70"C) is defined s a newheat transfei agent to heat the redctor to 57 aC wherepolrmerisation prccess (REACT-1) occus. ln the re@tionoperaiion, duradon of the polynerisadon !rccess rakes 7.5hou.s and tbe @action extent is sei ar 90%. Stoichiometricreacdoo nodel is used and the reaction stoichiomefic isdefided to convert one mss ofVCM to one ma$ of PVC,,(vcM) ) (Pvc)" (l)The ldsr operadon in the veseL procedu.e is to dis.hdge(TRANS OLIT) ihe slury reactor contenr to the blowdownprocedure P 14 (in vesel V-101). Simild to the case ordeminerdlisation water chdge, bLowdown operation of asubsequent reactor is also scheduled to start afte. thecompletjon a preceding reactor, due to the pipfg constranin the actual process. Tbe specification ol the prccess!e$€Ls is showd in Table 2.Tdble 2 - Equipneflt Specifcatiot TableEquipment Equipmcnt t .g volme (mrlidentical deceters dd a fluid-bed dryer rhat opeEre incontinuous mode. Thus, no scheduljng; qeeded in lheseprocesses. The dodelling s!@ificaiions ol eeh unirprocedure in tlrese downstream p.oce$ing L2ins re nextdescdbed.Stripper procedures (P-16 and P-17) {e used for VCMlemoval. The desigr component of the scippers is selectedto be vcM. 2880 kg of steaa at i loqc is infoduced to rbestripler to achieve a VCM remova1 of 99.9%. In thesinularion node1. rhe condenser ar rhe stripper top whichcoldenses the stem is onitied since vCM recovery faciliryid dol modelled. Hence, the srem leaves N enx$,u!togeder wirh VCM- Tbis teads to d slight de{eue in dEtotal amount ol w$tew er dischdged trcm rhe decdte.,which however co be omitted due to ils insignilicerThe slury thL\ (P-l? ddP'18) serve d tehpor:try storasefor tbe PVC s1u.ry before it entes into tbe two p@llelidenticrl decanieB (P-20 md P-21; not shown id Fig 3.2).Solid removal in the decant€B is sp€cilied u 997d for PvC,witb water los! of 21% (include cbiled water lost).E, I l .en "mrs ho{ rhese decr.pr ur i , r  ,  rhr  d. .1wasrewater of the processi while the wet lilter cake is sertto fluidised-bed dryers for noistu€ rnolal.In the fluidised-bed drye6 (P'22 and P-23), hot air ar 95 "Cis used to dry lbe wet fllter cake. Evapomrion Ete of waterand the final solid tenperatlre de set ai 916 ke H:O /h ed60'C .espectively- As a resDlt, 99.8% of the noisture (thecomlonent ofwater and chilled wrtet is cmoved,From the simulation model, the cycle time fo. a comlietebatch potymerisation process is 14.28 hous. This nodelalso reveals that approxlEately 17 batchs ofpolymensrtion reaciion car be proce$ed per day. whichnllies the real ope.ation of |he PVC mduhctding plant.Based on the dnual operating time ol 7920 hous, lbisranslates into 554 batchevyed,It should also be noied tba! all vesel procedurcs (P'1to P'10) m obsefled to have different cycle time (see GartiChad in Fig!re 3). This is maidy due to the schedullng olme TRANSFER OUTI op.Etions in each of the le&torprocetures (P-L to P-10). Since TRANSFER OUT'1opelatlon in each of Oe tacior is scheduled to smn afterfie TRANSFER-OUT-I olection of ihe peceding reaclo.ends, this creales a lag time fo. the prcduct to be dlch&gedfrom the sDbsequent reacto! befo.e the pfeceding redctorcompleies iis TRANSFER OUTI olemtiotr. A goodexmple is shown in Figure 3. As sbo*n, tbepolynerisation .eaction in P-ZK-?078 coftpieted at 9.62hr. However, due ro the TRANSFER-OUT-I of Pl/K-207,4 is in opeEtion, TR-{NSFER OUT I operation ir P-2/K 2078 cannot si.n until the TRANSFER-oUT-1operation in P'1/K-20?A ends ar 9-78 hr. Hence, lhis leadsto a lag tine of 0.16 br.!olytneisahon reactos K2O7A K2O7Jv 101V' l? mdV 132\)94100As the polyme.isarion process is cmied out in batchoperahon mode, efforts have been made ro documelt thescbeduting details for each of the batch vesel lrocedure (P'I !o P-ro). This includes theretup ine ISU'|), prccesstihe (W), Md srirt dn (S'l) ol each indilidual opeEtionin lhe ves$el procedup. The dellils of tbis schedulingsumma.r, 4e shorn in Table 3, wirh lhe prccess Gtntt chalrFrom the blowdo{n vessel, the slurry pioduct enres droL*o luallel idendcal downstream prccessing tmi$ whichindivrdually consist oi a stripper, slury tank. two pdallelICCBPE / SOMChE 2005'tdble 3 Schedrlins Stntury lor B6e Case Sin atotP-1/K207A toP r]/K2UtChdge in SUT = 0 min CHARCE-iI2O for second ddFf=20mln subsequenr reactor starc after theend of CHARGE-H2O inST = Beclnning of batch(CHARGE PVA)SUT=0mnST = 5mir after CHARGE- H2O(CHARCE-CATl)SUT = 0 sinPr=2minStart time = l0 mln after CHARCE-H2O slans(CHARGE CAT2)SUT=0minSt&t tiBe = 10nin after CHARCE-H2O stafis(vAcwM)SUT = 0 mid :lJsl Vacuum to 0,226 a6nlurce $ith N, to L194rrnST = After CHARGE-Ii2O ends Second V(uun ro 0.226 xtnchuge in vCM(CHARGE-VCM)SUT = 5 f,inST = after VACUUM e.dsHeat(HEAT,1)SUT = 0 min Use hot wate. (90 - ?fC) asFhal heating T= 57"CST = aier CHARCE-VCM ends(REACT-1)SUT = 0 ninPT = .+50 min Emisior = 20% of YCM (off ventST- Alier HEAT-I ends :ooli.g agent = coolirg wate. drChdge i! ChilledICHILLED H2O)Sln = 0 minST = ? h after REACT-I startsGRANSFER,OUT- 1)SUT=0tun Scheduled to stan after rhetransfer out ol'previous reactorST= rfter RE-ACT- I endsTCCBPE i SOMChE 2OO5Figute 3 Prccess Ganlt Chan for Bde Case SimulationConclusionA linulatlon model based on the optratilg condition of aPVC manuferuring process has be€n developed on ! batchlroces sinulation softwtue. The developed model rilhesthe real operadotr wherc 17 batch€s of polymerisationprccess are caried ou per day. This trdslates into 554batches of product per a.num.AcknolYledgementThe technical supporl ofMr YoeDg Chee Nyok of hdusharResin lMalaysia) Berhad is srarenrlLy acknowledgedReferencesIll Wesrerberg, A. W.. Hutchjson. H. P., Motl.d, R l.id \ r r f  e,  P.  lo1^ Pa' ."  r iar  h" ' t i '9Crnb.idge: Clmbridge Unilesiry ?re$.l2l Petndes, D., Salidou. E. and Calddnds, J 1995.'  ompu'er . .d_o Pro.e .  Anal)  i '  ond bcor or ic|  \  -uaDor oi  I  J.rr  ner. .  qumlr  In ul in Prod-rr ion- A aa.e )ru ' r .  b 'aP uola$ and I 'a?nBina'n848 529-541.H"ans. r .  lso/ .  Ba.cb PhmredLi !J Poce*D" 'er  and SimuLal ion.  Phatute ' t . rn tn. ,n""anlJaluary,February 19971 28-43.I r,r, S., Cdo. O. A.. winkler. S . venkaLrmalC..  LsBer R. Coore).  c.  L.  dd q. ' i \ .knr n.  R.1997. Process Sinulation for Recombinan! ProteinPoouf l  o :  .ost  t '  rmar,on b-d <c1nr \ r . j  A ral j \ i rlul Hepd .nx\e I Expre"ed 'n Cr hp,\ hia aliB iotechnolasy atut Biaenqineerins 53(6): 575-582.KouLoJi ,  A,  Cdl lndrdn' . ,  J d d Pe.r  dr \ ,  D P.2000. f t ' rcughpL. Ana\. i  dnd D"bo,, l -__ b.d .  ilnr8l . led Brch.hemicclPrc.e\ \e .onD.\pt  a"dCheni.at Enginee/in8 24: 1387'1394.Perndes, D. P., Koulouris, A. and Sileui, C. 2002Throuebpu Andlysis dd Debofileneckilg ofB,ar.nui , , ' . rnB Fac. l iL ie":  A Iob n P,o.eSnnulato.s. EioPiram August 2002: 2 7.Pq oe ,  D. P.,  | \o, lo- ,  . ,  A.  dd S 1. i , . .  2001. TheRole oL Pro.er,  Sinula. :on in Phlr"reu icdl  FGFDe\eloprnenr dnJ PrcduLt .omercidl / . r io 'PhoruceuticaL Eneiheering 22(.1): 56'65.Oh. S. K. w.. Kue(. K H. x d wong. v. v. T. 2001.D- ;g r .  Simul-Don dd Ophm .ar ion of  A I  - ,Be sL. leMoroclonal Andbody Production Platrt: UpstreamDesren. Phdmaceutical E^sineeins 24(6): 42-60.InteUigen, Inc. 2045. SuperPra Designer Uvr'sGatdc, Scotcb Plains: Inrelligen, Inc.t4lt3lt5tt7tt6lt8ltol

Process modelling of a PVC production plant

http://eprints.utm.my/5375/1/ChanJunHoa2005_ProcessModellingOfAPVCProductionPlant.pdf

Process modelling of a PVC production plant

Abstract

Similar works

Full text

Available Versions

Universiti Teknologi Malaysia Institutional Repository