Document O3NJRnyKavn5zZd89o2mQ1DdQ

| >OLYVINYL chloride--PVC 'hardware' involved' --is now a household What .lie the features and piob iuini that arc likely to be associ sivo material to liquefy and store since it lequiros special and ex trcmcly costly c o n s l r u e (i o n (he licensor nnd others dining tt. design stages. Hie i-i'nrt-iiur opmulUpTM fulH_h word. A considerable amount ated with this' materials Vttutevo thorofoi'e-utat c/nriod-ovfl-n"S baiiit o*elgUfrai of information on its manu IIow will they arise in the pro'- built Jflt'ftnvs.-rald'iitii-ojiai stormzoS .frumoees rv rjv.qt S frnm-s'rrt facture, variant forms and applications has already ap commissioning and commissioning operations? IIow aie they likely to dtITer m peared in Double Bond and aspect, in rotation to the three This Keans.HhaUUu&^tiqijsLtt. ancr the clacking section must be com missioned and run in balance `moving up or down' m through ' in nnolhei .sal t lofnrc moving foi Ziliimiis which wi separate out the purified VCM pn elsewhere mam control sections concerned put together, as conditions dictate. duct and the HCt. Vinyl chloride monomer-- with the production--the opera tional, technical control and mam VCM--is the material feed tonance sections' stock foi the PVC process, In Here arc seme answers , . . PARALLEL TRAINS COKING Ilo\vovci,Jiis-all-*Ui#-otitasoc- The main problem facing us n IjjWir-crTvCM complex lholltrK ` tins scrlion will bo in mnintinnini which by moans of an 'initi hn^^i,?!rt0S,fil!07nall0,Vrnu?,CCfi''''-P-kCt3fi-bi.lio,TMin#,. are-a---g-a-Ii-n' associated with') good fnmarr on strimm limes it ated' polymerisation reac tion, undei carefully con trolled temperature condi has ahoady been in- operationiJM^ .corrosion, particularly in the r*/ J!1*1"" ,^ny - action none In order to ensure squui'18 ,'lcons,ct* rro.m t"5^Jnawai*hrCtrallnuily -of--BSIincoi w^vii<iSPh3*fheniiqipAi5,0 l'l.inm opoiation and luss on and ol JjwerUi1 enking up ol Che^qpilfioh.^uwioeae eisewli ei-c can m* (rq;o ,3Q to 40 days depending oi tjtg, , inollted oTopprallon, th< 9; tions, VCM is converted to PVC. The VCM supplied-as a clear, colourless liquid-- must be nf extremely high chemical purity, Demand for PVC, and con sequently VCM, is Increasing and production complexes for these materials arc a notable'part of the Baglan Bay expansion project. So far as BP Chemicals International is concerned, all VCM and Tiie existing plant will become <T poit of the overall VCM complex, especially the crude section. Fur ther EDC will be produced by a new direct cliloi matron section which will produce, about twenty five per cent mom crude EDC than Hie unit curiently m operation. Over the last few yc.ns the mam problems associated with the direct chlorination plant have baer concei nod with corrosion mem -- in pariiculae, and around the reus action cooling section. operation, we have broken the jjrohtp-nf Hie ifj-fiintjg,.hr..tHvd-*un roaclJon cone up into two equal each cleaning ou halves oi 'parallel trains'j_'(liU'IT operation. Viau will bo capable of producing Wo leol we have the ability <- about I he same amount of crude ovi'i cnnie the fli-si aspect b> EDC as cither of tlui direct chlori establishing good procedures am nation units training based on available know Each half will have its own steam how. We have already started generation system, the steam be with the close assistance of on, ing gejuaratotr by (be heat given colleagues in icisemch ami dc nipt'-by the reaction, T-he., iscpiip-'^ vclopmcut department, Epsom, hint Will bo of complex design ) closer study of feodstock const > both nxr-rabTirtrddh' JtflfftlOd mid In/ tuents, By discoveung those which .materials of constmtettott. arc more prone to produce coke ESCTOR FEATURES deposits we shall improve on the coking-up times in tho longer PVC production has previ ously been carried out at Barry. TWO ROUTES By thermally cracking ethylene (hchlontlc -- EDC -- VCM. is ob- tinned along with hydrogen chloride. Tins ciaelang, or `brent ing up', Is achieved by passing the , EDC through tho coils of furnaces which are held at high tomporature The cracking "stage is fol lowed by a separation 01 purifi cation stage which allows the VCM and HC1 to be dissociated from small quantities of unwanted re sidua! compounds and fiom each otliei--and at the required level of purity. VCM Is the 'bunding hncli' for PVC, and EDC is used ns the 'building Illicit' for VCM. Thus, heroic we can start any part of the crocking stage we must first produce E11C--and we need twice tbc amount or FIDO la make the required amount of VCM. Par economic reasons--you'll see why soon--wc mate EDC by two routes . , . LOCAL EXPERIENCE , , The reaclois arc about teuelye. -ieaW in diameter and hove about ISagbui Bay personnel have .130 long coth in each through csscufially laid down (be design whioh wafer flows to -keep tho re- conditions for the new direct aetor temperature under control. chlorination section based on local Because the catnlytic ageat experience. Certain mechanical which assists the reaction Is of a changes have been designed in, al `fluidised1 character, In so far as though (lie basic process principles It Is always in motion as compared and control techniques have been retained. with other 'firitli*Jj*d-4ypc enta' lysis, spaetateffust cyeloneslare also It is hoped that tho modifica built Into tfVlWlHWbrreiini reactor tions incorporated will show for a to pi event the expensive catalyst satisfactory and quick commission ing in the short-term aptHA from (lying out ef tho top. Downstream-of* EWK'TdTCCVoT-'ltie production losses fronfucloSHfi' Ft ants are `nuenehed* In larger once sustained opcratioiCiMg-1 toroai-e f)|f- _MMlf,h--p-Mtnam achieved. The oxyhydrochlorinatlan pro cess is a new process se far ns B Chemicals International n con cerned. It will bo used under licence from the B. F. Goodrich Chemical Company of America and e's'S products is such that the towers are lined with synthe tic rubber, then a further tayer of Macid resisting ,brickwork, and "packed.wittr'ceramic tiles.' " , The piping in tMl WtMro seolidn icdlW ptfisttWn the Hoechst Company of Germany who are co-licensors. Both these companies havo operated this pro- e,lu,,llc,, . iii8 titanium its ibis 'are muelf in cess Ibr many years, and other "--nit;-control 0f th, Itceruras are currently operating o^ves-^rtl'tfllWrTSibn and-Wm 512G nan>'- c*nadfCwnw*s analysers as found ne; AJampaenri,ca and, more recently* in"--BWy"-11)-tli,i iiiust-recmrt-pWHS of this kind, and it Is imperative that term. Nqyoi thclosa, we must expert considerable' and frequent malnl.cnanco uround the furnace1 area copuactod witii those (-loaning pro cedures, and also in ard arotind Tnc various tower and lower bollup systems for the same reasons. The products from the cracking section are finally directed to the separation and fractionation sec tion, where the vinyl chloride pro duct is separated and purified be fore storage and where the hydrogon chloride is separated and re turned to the oxyhydrochlorina tion suction. SUMMARY In summing up H muy be saicl that the mam problems facing us during the preroinmlisionmg and commissioning periods, over and above the normal ones met at any similar stage on any othor complex, will be those which will eali for extreme care m ensuring dial all equipment ts correctly m stalled, physically tight, and care fully anfi efficiently dried- out to rqdupe corrosion potential. All machinery must bo tested 0 The oxyhydroclilorlnotlon route, BADGER-l*fMOWlWW~-- _ 'these are carefully managed and?,, and run up, and as many perl- in which etliylopc 11 reacted with Twj" *'** *' * MW I IV 1 tmwaailHntfaeiinnaeAd kbneilkli oatt ItVhiert oconiinnmmitsa-., p*!hae.r.aIl -sections AaMs ,.poNsHslti.bl l-e acao.r the by-product HCI resulting from, '""W sS"H >'e th first d sole > sionmg stage and thereafter. rectly commissioned with the the cracking stage so that alt oft__ Ilcunsecs .InJilUiiitt* .In preparing The EDC -purification system materials they will be handling, this by-product ii reabsorbud ~~llUir-piuL'ess;n engineering and con comprises tlireo autumns of some before the main reactions arc ini The direct chlorination route, trol design aspects of this plant wc what standard design and moans tiated by introducing the basi- in which elhylcne is reacted have obviously been largely guided nf control, and apart from nor feedstnek materials directly with chlorine. by the licensors' and licensees' mal corrosion aspects should throw in tho loagcr term our nlm must Both routes contribute in alllast most rocent plants, oud it has been up problems mainly associated be to nintutalH safe operation and equal measure the required EDC. of distinct advantage to us that with ensuring good fractionating techniques of maintenance at all m erode condition, foi VCM are- Badger Limited, selected as our coutrol to the fine limits and speci times whilst achieving an eaily durtiaa. Refore this EDC ran be mechanical contractors, has built fications demanded. understanding ef our problems fed to he cracking stage it must . several of these plants In overseas first` `be puri-fied- to remove un countries, and has had mechanical HELPFROM BARRY and limitations hrespective of their character. wanted light nnd heavy materials,' design associations with this par-, ' The cracking section is again fn this way we woute hope not The evor-q VCM complex Is tlcular process since the early pilot operated under licence from Cor.d only to achieve eventually a highly llfli-trateu ii simple block terms plant days. rich and as such has been used clficuint operation but also, in io in the diagram on till*. page, As was indicated earlier tho pro at Barry for several years, albeit doing, collate sufficient data and cess is concerned with producing on a smaller scdIo. ` knowhow to allow for Uic design HARDWARE What ol the type of plant, oi elude EDC from ethylene and re circulated hydrogen chloride. Hydrogen chloride is an expen- . Wo are foitunatc In having lmil tho opportunity to (Haw on this experience in addition to that of and Installation of more efficient, and large), similar complexes in She future __ ___ ------- . . as V Hi---<- RSV0030198