Document LJkB5nmrgK1p9Ry7Ka2NQvMOg

! I 'I ]if"rnf rPiHi sJuj ili'LLAkL'lJLihiJU X\ fj a F/S*! x\ p'!j /*> P*i\ j; tw*n ; p33^. f-;"*f\ (f% rfrf^ 17 \^giilljfS <uii aiiOiTa a iiy dOa l* y^y aaa r. n n \Wii: *?*v~* \-*yo ! H rT-^l :! il \i u U*Ut & n nn n ti pM^i. rv3r6,`>>AYr\*7 \'v (* H r| ;l '*> t l;b \!j ''?!' U Ly\ li s [( )} % fj V'/ (j \yu Wu UVs* W-u 13 ^4 U \*& Ei 'W \i W This survey of the VC?J! (vinyl chloride mar,oner) industry, cammercia! dovoiopmonis, cneiiusiry, commercial processes end new developments indicates that VCM can remain competitive with rising crude costs R. VJ, McPherson, C. M. Starks and G. J. Fryzr, Continental Oil Co., Ponca City, Okla. --.-TDf.yki.cpment -of ti:f. -vinyl -chloride-monomer '(VCM) `industry 'lias been "closely'Interrelated with'the polyvinyl chloride (PVC) industry. Effectively 9$ percent of the VCM production goes into the manufacture of . PVC. Therefore, technological advances in one area have 'significant impacts upon the other, producing a domino -effect. Tills, in conjunction with increasingly tighter en vironmental regulations, lias insured a continuing evolu tion of VCM technology. It is timely to review the state of the art. INDUSTRY PROFILE The commercial significance of vinyl chloride monomer (VCM) can be highlighted by the statistical ranking of the 19th largest chemical commodity in the United Slates. Turning our view upstream, we realize the significance VCM plays in wedding the petrochemical and ch'oroalkaH industries. Fig. 1 schematically depicts the U.S. market integration surrounding VCM. Pondering the posture individual companies present to the market (Table 1), one can muse as to the motivational forces behind their respective business strategics. It holds that, if S6 percent of the VCM demand in 'this country is derived from PVC, then VCM's future is inescapably tied to that of PVC's. Within the scope of known-unknowns, one basic fact attests to its longevity. On an energy-equivalent basis, PVC is one of the most energy-efficient construction materials available (Table 2). This follows even after weighing the socioeconomics of health and environment. Looking at the two principal components of the PVG --Fij. 1--j-Shcws Uio U.S. mnrfc^t integration sunccraino vinyl chloiido industry. llYUroCARRON PuOCF.SSINC March 1979 CCS 000031668 75 VINYL CHLORIDE MONOMER market. flexible or plasticised products, of which fabric for automobile interiors and electrical wiring insulation arc examples, and rigid products, including sewer and u ater pipes,. electrical conduits and shoe roles, we find the ricad aggregate .crowing at 9 percent per year, as opposed to the flexible area which is increasing at a rate of approximately 5 percent. Within the past few years, the rigid aggregate lias surpassed the size of the flexible market which can be witnessed by the creeping seasonal response the VGM industry has to construction, the major end-use outlet fer rigid products. Rg. 2--Relative energy content of various construction materials. -- tx i ABLE 1--NanrspLoio capacities(Mh/i pounds) Careen........................... Cceoro............................ DiST.snd................. Ethyl............................... B. F. Goodrich.............. ICI................................... M;nc%rem.................. PPG................................. Shell............................... PVC 550 5:3 tiers lion* 175 UCS lior:9 No--* None Nc:ie 420 ver* 3CC 700 l.CJO 2,250 300 1,1:0 300 300 C.-1H 3,040 170 Ethybns Non? 650 Nona 4.S20 liana 350 Nona Hers None 2,700 Irene Chlorir.3 Pione None 2,500 8/-C3 503 250 300 flcne 2,050 200 m TA3Lc 2--Commercial Jypus of VC*.: technology I. H,;i. Purity Acetylene Fc-odstock II. rii::t-? or Mix-d Gn> r-adstock III. Balanced Ltiiyhr** cck A. Air-hasrd Cxvcb'c-ina(ion R. Gxysen-Basad Or-clilonnalion Develcper/l'cen'or Do.y........................... Ethyl. SCI, Solvay...................... B. h G'cdrich.......... f.Ms'ji Taatsu................. *..................... f.toavipto............ P.-G.......... Vfsrja? rp'.ilenc..................... . '-S'.a j`a*r;-. TcMwrr.j Sad j........................ ICI. TccbnoScjy Basic Cx/chiorination 111 A Mi A til A,B II III D m A 13 i;i B in A in A.B in A in A t I-- Over the course of the past ten years, VGM has be come a major'item of international commerce, with the United States the architect of this business, between 1975 and 1977, eight percent of the VGM produced was carried offshore, making it third only to styrene monomer and toluene in the generation of trade dollars by a chemi cal commodity. This factor has tended to fill in the valleys in demand brought about by construction. More signifi cantly, it lias permitted the VGM industry to consistently operate near capacity levels by exporting domestic sur pluses into the world arena. Looking at the global VCM market, we view forces at work changing the disposition of trade. Beginning within the past five years, Europe as a whole has swung from a net importer to exporter of VGM. With ten billion pounds of VGM capacity integrated to where there is less than 15 percent mer- chantly derived PVC demand, producers are now chal- lenodinog U.S. material for a share of the remaininog world exports. ` ; ,;,A Japan, whose five billion pound VCM industry was built to serve the whole of the Asinn-SouLh Pacific market, first in PVC and then later in VCM, has witnessed a major influx of U.S. and now European monomer pro ducers into their domain. j The present situation- in the U.S. is manifested by. cheaper feedstocks, vis-a-vis energy, and an. undervalued currency that together are'able to o'Fset logistical costs and remain competitive in the consuming markets. Eventually, merging energy parity and emission cost pass throughs will leave U.S. VCM no more competitive than that of any other nation. We conclude, therefore, that exports will continue as developing third world markets seek to establish a plastics industry in advance of petro chemicals. Conversely, the major market imbalances of the past have gone by the wayside, and market growth will come from the domestic sector, l'ig. 3 depicts the longer term outlook for VCM. In making cur projections, we assume that the growing capital commitment required to make VCM will not force PVC to become uncompeti tive witii alternative* products. Secondly, we foresee no major technological innovation on the horizon that could radically alter the economics of production. We do sec, however, technological improvements of degree that di rectionally level out the inflationary trend of plant con struction. Within the U.S., we project a 700 to 1,000 MM lb. per year grass roots plant will be required every two years to meet demand. It is within the scope of this time frame that innovation will be tested. COMMERCIAL DEVELOPMENT VCM was fust produced commercially in the early 1900s via reaction of 1ICI and acetylene derived from calcium carbide. VCM usage in the manufacture of syn thetic rubber accelerated dramatically during and after World War 11. This increased demand prompted searches for more economical hydrocarbon feedstocks. Acetylene s was recovered fiom refining steps, and new technology' was developed to produce acetylene specifically from hydrocarbon cracking. - ' '4j Ethylene became plentiful in the early 1950s. Direct chlorination processes to produce 1,2-dichloroethane (I-nCl) from chlorine and ethylene were devclojxrd in CCR 0 0 0 0 3 1 6 6 9 h 1 * f: i * v. 1. 1. Mir. VCAl irn-x _^ :r:cr- Un}. i)d \vahtt. d .i nro- i non with EDC cracking technnlogy to yield \ CM. 7it * r:JO''rpCC<s yichinJ byproduct 1IC1 and did not proV''.'irnrncdiatcly, except in conjunction with accty- technology which needed HCl to produce " ' [a die U.S., ethylene production from abundant sup- 'j, cf low cosl El'O began to predominate. In Europe, *vvpi.>c prices abo continued to drop, though not to the nc decree since higher priced naphtha and gas oil die primarj' feedstocks. Therefore, while European '"-cJu'ccrs continued to use acetylene-based VCM lech- -ele-Ti American companies moved rapidly to ethylcnetechnology. With the startup in 1958 of the first T.-ge scale oxychlorinalicn process to yield EDC from PCI and ethylene, a new era in VCM technology began, -jive '.`'balanced" process allowed production of VCM \I frrjn two commodity chemicals, chlorine and ethylene, vdtheut voluminous byproduct HCl. VINYL CHLOniDE CHEMISTRY '-''Large scale production of vinyl chloride was first done bv addition of hydrogen chloride to acetylene: m -Ilydiochiorination of acetylene acd ' Catalyst :st* 7.;>; HCl H- HC = CII -------------- - HC* = CHC1 (1) rts. tss- 7.-However, much lower costs for production of ethylene ;.ii) than acetylene and the discovery that 1,2-dichloroethanc ,;{EDC) thermally decomposes to vinyl chloride in excel cts lent yield Jed to tire following reaction sequence as the rr -predominant manufacturing method for VCM: Direct chlorination of ethylene r,c - ' CIT- = CH2 -t CI2 CICH-CIIsCl EDO cracbiug to VCM ; i- - Heat '' Vjv" C!CH,CH2C! ---------- CH8 = CHC14* HCl 'ci ; ...Tins method was especially advantageous for these producers having a use for the HC! by product, particu i- larly so if acetylene ware available; since then, a bal anced VCM process with no coproducts could be op- `eraicd. :s , ' EaLcr, the discovery that oxycblorinaiion technology could l:c applied to ethylene to give 1,2-dichlorecthnnc .in high selectivity now allowed a completely balanced process based only on ethylene and chlorine r.s feedstocks. ' O.xychlorination of ethylene Catalyst CII2 ~ CII3 H- 2HCl *f 1 /20s--------------- cicii2cirsci + n2o At present, about 92 percent of the vinyl chloride pro duced in the United Stales is from plains that use th.e balanced process based on ethylene via chlorination, oxychlorination, and thermal cracking of EBC.1 These three separate steps arc described in greater detail below. Additionally, the* h\diucMorinatiori of acetylene is also % discussed below since plants using this chemistry arc still Fig. 3--U.S. vinyl chloride n2mc-p!aJe capacity versus demand. in operation. Moreover, some recent crude oil cracking technology may narrow the cost gao between acetylene and ethylene with consequent revival ox interest in VCM from acetylene. Some chemistry on direct preparation cf VCM from ethane is also briefly outlined. Direct chlorination c- ethylene. Direct chlorination of ethylene to l,2-dich!orocthane is almost always conducted in a liquid phase reactor by intimately mixing ethylene and chlorine in liquid EDC. Ferric chloride, a highly efficient and selective catalyst for this reaction, is normally used in commercial processes. Amides, such as n,ndimcthvlformamidc, have been reported to increase PVC selectivity.2 Oxygen, frequently present as an impurity in chlorine, likewise increases EDC selectivity in direct chlorination of ethylene by inhibition of free radical re actions that give 1,1,2-trichIoroethane. Direct chlorination reactions may be run rich in either ethylene or chlorine, depending on the methods available to the plant for handling offgases from this reactor. Con version of the lean component is usually 100 percent, and selectivity to EDC is greater than 99 percent. 1,2-DichIoroethanc, as it comes from the direct chlori nation reactor, is frequently of sufficient purity for crack ing, except that it may contain ferric chloride, which would lead to rapid fouling of the cracking reactor. To avoid expensive purification of this already pure EDC, one may remove FeCl3 by adsorption on activated carbon3 or other-solids.'4 Alternately, one may operate the direct chlorinntor at the boiling point of EDC, taking pure EDC overhead and using the heat of reaction to supply the heat for vaporization.r'*c'7'8 Oxychlorinrtion of elhylono lo EDC. Ethylene oxyclilorination is normally conducted at temperatures of 225-325" C and at pressures of one to 15 atmospheres. Catalysts for this reaction almost always contain copper chloride and sodium or potassium chloride deposited on alumina or oilier suitable support./Thc detailed mcch- Hydrocarbon Proccssinc March 1979 CCR 000031670 77 VINYL CHLORIDE MONOMER anism of the catalyst's activity is not known, but it is recognized that cupric chloride is the active chlorinatin': agent. Tin: cuprous chloride produced is rapidly recon verted to Cud- under the reaction conditions, but the presence of some cuprous chloride is thought to be advantageous because it complexes with ethylene, bring ing it into contact with CuCF for a long enough time for chlorination to occur. The sodium or potassium chloride serves to increase EDC selectivity, mostly by .inhibiting formation' of ethyl chloride. Other catalyst components, such as rare earth rnetal chlorides, sulfate salts, ferric chloride and numerous other additives, have been de scribed in the patent literature. Good temperature control of the highly exothermic oxy reaction is a key element in successful production of 1.2-ciichloroethane. Temperatures higher than about 325C lead to increased byproduct formation, mostly through increased dehydrochlorination of EDC to vinyl chloride followed by additional oxychlorination to give products haring high levels of chlorine substitution. High temperatures also increase the amount of ethylene burned to carbon monoxide and carbon dioxide. Of equal im portance, high temperatures deactivate the catalyst by highly accelerated coking and consequent powdering of the catalyst units and by increased sublimation of copper, chloride away from the catalyst. Temperature control in fluidized bed reactors is main tained by the excellent intermixing of the catalyst par ticles and by use of internal cooling surfaces.10 Tempera ture c-mrol in fixed bed reactors is more difficult since "hot spots" tend to develop. To keep the hot spot temperature below below 325 C, yet get maximum utilization from the reactor, it is common practice to pack the reactor tubes with active catalyst and inert diluent mixtures in proportions of each so adjusted as to have low catalyst activity at the inlet, steadily in creasing to maximum activity at the outlet. This grading of the catalyst activity flattens the temperature profile, allov.ing for good temperature control with high produc tivity. For example, one patent9 indicates the use of four zones with 93 percent, 85 percent, 40 percent, and 0 percent, respectively, of the active catalyst pellet-: replaced by inert graphite. As an alternate to using inert materials in the catalyst bed, catalysts, each with higher levels of CuCl; and consequently of increasing reactivity, are sometimes used. Fluid bed oxychlorination of ethylene, operated under good control, results in 94-97 percent eihylene conver sion, 95-97 percent HC1 conversion, and HOC selectivi ty in the range of 94-95 percent. Fixed bed oxychlorinnlions are normally run with excess ethylene relative . to 1IC1, resulting in 93-97 percent ethylene conversion, 9 4-95 percent HC1 cons L-rsions, and 1CDC sclectivities of 93-95 percent. 1 hose data do not include recovery of excess ethylene in subsequent reaction steps. Excess ethyl* V cr.e.m sent ea-.es from oxychlorination .is normally con verted tr) EDC by direct chlorination with chlorine,11'12 although, if oxygen is used rather than air, the excess ethylene may be recycled directly back to oxychlorination. Byproducts of ethylene oxychlorination arc vinyl chlo ride, ethyl chloride, 1,1-dichIorocthane, vinylidcnc chlo ride, ch- and rifir/j-l^-dichloroethylenes, trichloroethyl ene, chloroform, carbon tetrachloride, methyl chloride, methylene chloride, chloral and high boiling compounds. All of these byproducts present problems in one way or another, such that their production needs to be minimized to lower raw material costs, to lessen the difficulties of preparing pure EDC, and to prevent fouling in the y cracking reactor. Chloral, in particular, needs to be re moved since it polymerizes readily in strong acids to :: give solids which clog and foul operating lines and controls. . _? One must also take care to see that the feeds to oxychlorination are pure. Normally, the only problem is -..s. with, low levels (0.1 to 0.5 percent) of acetylene present H in the IIC1 from cracking of EDC. Acetylene in the feed leads to the formation of considerable highly chlorinated W byproducts and tars. Selective hydrogenation of this acetylene to ethylene and ethane is practiced by many A companies.13 ? Oxychlorination with oxygen instead of air. Use of oxygen instead of air for ethylene oxychlorination has received much attention.11'10 The outstanding benefits from using oxygen are avoidance of expensive facilities to recover EDC, ethylene and other chemicals from the large nitrogen vent gas stream; a' large reduction in the quantity of offgases that will probably need to be in- cineratcd; and the ability to use ethylene as a diluent for oxychlorination, a procedure said to improve heat transfer in tubular reactors. . j '* ' - Puriricafjon of EDC for cracking. Great care must be taken to ensure that EDC used for cracking to vinyl chloride is of high purity, normally greater than 99.5 per cent, since cracking is exceedingly susceptible to inhibition and fouling by trace amounts of impurities. Additionally, the EDC must be bone dry to prevent excessive corrosion downstream of the cracker. For these purposes, one must consider removal from EDC of byproducts from three sources: EDC from direct chlorination, EDG from oxy chlorination, and EDC recovered from the cracking step (see below). EDC from direct chlorination is usually qtiite pure, greater than 99.5 percent; and, except for the FcC13 present, it needs little further purification. As mentioned previously, ferric chloride may be removed by adsorption on a solid, or the EDG may be distilled away from FcGlj in a boiling reactor. Alternatively, the ferric chlo ride may be removed by washing with water, usually in conjunction with oxy-EDC. 1,2-Dichloroethnne from oxychlorination contains a variety of impurities as listed previously. EDC from this -source is usually washed with water and then with caustic solution to remove chloral and other water extractable impurities,"0 Ixhv boiling impurities and water are taken overhead in a fh-st (light ends) distillation column, and tlicri pure dry EDC Is taken overhead in a second (heavy ends) column. EDC" recovered from the cracking step contains an - CCR 0 0 0 0 3 1 6 7 1  v (.,in.; l M.r], ,i ml.,;;;!; t ,c i.v.: m imivi i: cut... , Ckh toprrne, if nut ,i!u'u ti by rhcmicnl treatment, i 011- ccntmtes in tlu* light cm's column where it am polymerize ... lo joliii or rubbery materials which seriously foul and u]7sct this column. Trichloroethylene forms an azeotrope with EDC, boiling very close to EDC. If it is not removed in sonic way, it accumulates in the EDC, leading to re duced cracking rates and increased fouling, both impuri ties may he removed by subjecting the recycle EDG stream to chlorination prior to distillation.21'2'' Treatments with - HClr<'20 and by hydrogenation27 have also been patented as methods for removal of chloroprene. Cracking of i,2-dich!orocthnno to vinyl chloride. At temperatures in die range of 425-550 C, and near at mospheric pressure EDG undergoes clean thermal dehy' drochlorinntion (cracking) to yield vinyl chloride and' hydrogen cloride: Heat CICIRCH-Cl ---------- > CHa -- CHC1 + HC1 The mechanism of this reaction has been extensively .. investigated25 and shewn to involve a sequence of free radical intermediates. Use of pressure up to 25 to 30 atmospheres during cracking at temperatures of 500-550 C provides better heat transfer, reduced equipment size and easier separa- tion of HC1 from the product by fractional distillation. EDG conversion levels arc normally maintained in tire range of 50 to 60 percent at residence times of 2 to 30 seconds, with relcctivities of VCM ranging from 96 . to OO*- percent. Some byproducts generated during crack ing act as inhibitois to the free radical sequence so that increasing severity leads to smallerand smaller increases in EDC conversion with, correspondingly increasing-levels' ... of byproducts. Various materials, such as chlorine, bro mine, or oxvsrcn have been shown to be initiators for EDG cracking.2* Recently, however, exclusion of oxygen -/ is claimed to result in considerable reduction of fouling on the cracker tube walls.23 A rather spectacular claim has been made that use of nitromcthanc as an initiator provides EDC conversion levels of up to 92.5 percent ; at 480 C.30 An important processing requirement in EDC cradling is rapid cooling or quenching of the reaction mixture. It" cooling is done too slowly, substantial : yield losses to heavy' ends and tars result.25,00,31 : Byproducts from the cracking reaction include acctylcne, ethylene, methyl chloride, butadiene, vinyl acetylene, benzene, chloroprene, vinylidenc chloride, 1,1-dichloroclhaiic, chloroform,, carbon tetrachloride, 1,1,1-irichloroelhanc and oilier compounds. Most of .these impurities remain in the unconverted EDC fraction and are re moved when this stream is distilled. Ethylene and acety lene codistill with the 11C1 and arc thus routed back to oxychlorination (after optional hydrogenation of the acetylene to ethylene), Methyl chloride and butadiene mote or less codistill with the vinyl chloride, depending on the efficiency of the VCM fractional distillation sys tem. Addition of chlorine or carbon tetrachloride to the cracker feed is claimed to supptess methyl chloride for mation/1 Removal of butadiene, a contaminant which can interfere with polymerization of 'VCM, has been KOI addition to acetylene. Recent development of a new crude oil cracking process21 using very high tem perature steam (2,000 C) as a heat transfer fluid pro duces substantial yield of acetylene along with ethylene. Under some economic and geographic conditions, the use of this cracking process may be advantageous and may, thereby, provide acetylene for vinyl chloride pro duction. Typical conditions of hydrogen chloride addition to acetylene arc total pressures on the order of five to 15 atmospheres, temperatures of 150 to 180 C, and use of a mercuric chloride-on-carbon catalyst.38 With stoichio metric quantities of reactants, essentially 100 percent con version is observed with VCM selectivities on the order of 98 percent. It is notable that ethylene does not react under these conditions, thereby allowing the use of mixed ethylene-acetylene streams as feeds. Ethylene, easily re covered from the vinyl chloride product by fractional distillation, is then chlorinated to yield 1,2-dichlorocthane. Other catalysts have been shown to be effective for addition of HC1 to acetylene, but HgGl2 is vastly supe rior/5 However, in addition to the general toxicity prob lems involved in working with mercury-containing substances, HgCh has appreciable volatility under the above reaction conditions leadingO to a need for considerable care and control in operation of the reactor. In fixed bed operations, I-IgCl2 vaporizes from the hot spot of the reactors, condenses at cooler locations downstream and results in continuous movement of tire hot spot downstream with eventual loss of catalytic activity. This loss is minimized by periodic reversal of flow through the reactor. _ E`hanc-h.sec* vinyl chi0iide"J?rocessss."A"number of patents dealing with chemistry for conversion of ethane to EDC and/or VCM have been published in recent years/3-54 Most of these reactions involve high tempera ture oxyc.klorinations, such as GHjCHs -r HC1 -1- C Cuds Catalyst 350-450 C CHS = CIICJ -!- 2H-C However, these processes suffer from a number of dis advantages, the most important of which includes low sdectivitieq low conversions and difficult operating con ditions such as CuCl2 sublimation. One reaction system based on ethane, called the "TRAN5CAT" process, has been developed on a large pilot plant scale but is not yet in commercial practice/5*53 The chemistry' of tins process is a complex series of re actions, generally involving chlorination, dehydrochlorinntion ami oxychlorination. A mixture ofTcthane, eth ylene, ethyl chloride, chlorine and HCl are fed to a melt of cupric oxychloride and potassium chloride, yielding vinyl chloride, water, and cuprous chloride as the main products. The cuprous chloride-potassium chloride prod uct is taken to an oxidation reactor where the cupric oxychloride is regenerated by treatment with air. Vinyl chloride is separated front the organic product and puri- HvnnocAtutoN I'uoclssino March 1979 CC* 000031672 79 -airvarTiry- sk* j*r>* i-^rf, .1^2 VINYL CHLORIDS MOHOMER TABLE 3--Current VCM technology sources fied bv fraction.*)} distillation. Removal of about 0.4 per cent butane plus butenes present in the main VGM cut represents a very difficult separation.45 Ethyl chloride and ctuvJene can be recycled into the feed. Chlorine values in the chlorinated byproducts can be recovered by incineration and then feeding these gases to the cuprous chloride oxidative regenerator reactor. Disposal of byproducts. Disposal of byproducts pre sents special problems for vinyl chloride-manufacturing plants, since a variety of gaseous organic liquid, and acqueous streams must be handled, each with its own particular problems. Vent gas streams from various units may contain small amounts of HCl, chlorine, ethylene, vinyl chloride, methane and carbon monoxide. These streams may some times be treated by. scrubbing, chemical treatment,' sorption, or other methods to recover some chemicals when economically justified. Otherwise, the common cleanup technique is either incineration or catalytic com bustion followed by recovery of HCi from the vent gases. Two organic byproduct streams are produced. The light ends contain mainly ethyl chloride, cis- and trans~ 1,2-dichlorcethylene, chloroform and carbon tetrachloride. The heavy ends or "tars" contain mostly 1,1,2-lrichloroethane, lesser concentrations of tetrachloroethar.es, chlori nated butanes, chlorinated aromatics and a large number of other compounds present in small amounts.' These streams are normally fractionated to recover useful com ponents. the others incinerated to recover chlorine values either as aqueous or anhydrous HCl. Process water streams are steam stripped to remove volatile organics followed by neutralization and then treatment in an activated sludge system to remove non volatile organics in the water.45 C0r/iMERCIAL PROCESSES broadly speaking, there are three types of VCM pro cesses in commercial use today. These are categorized as acetylene, ethylene, or mixed gas based on feedstock re quirement. Within the "ethylene-type" plants, further classification is desirable to distinguish the type of oxychlorinatjor*. technology used, i.e., oxygen versus air feed stock (.ee Table 2). Over 90 percent of the world's listed 3.7 billion lb. per year VCM capacity currently is baaed upon the balanced ethylene, feedstock route. Of this, just under 90 percent uses air-based dxyehlorinaiion. How ever, of the projected worldwide plant .startups For the period 1979-1901, approximately 30 percent of the 7.7 bilhort lbs. per year VCM will be derived from oxygenbased exychiormati.m. Oilier existing producers will un doubtedly be evaluating the conversion of present airbased plants to the use of oxygen during this time frame. Table 3 presents a summary of tin* technology sources in use today, k is thought that the technology currently V licensed by ICI and Solvav is similar to the process normally attributed to Ethyl. Therefore, all arc listed und-r Ethyl's technology. It is interesting to note that severed plants exist where the oxyrhlorination process Exi?tia2 VCM, Teduiobay Source Plants r.;M Lbs./Vr. 1. B. F. Gccdricit... 2.Hoec!'.st/DFC*.... 3. St.iuffcr/SFG\ .. 4. Stcu"cr............... 5. Elr.yl,Sotvay, ICI.. 7. PPG................... 8. Phonc-FouUna.. 9. Monsanto........... 10. TcycSiria.......... 11. Tckcyams Seda.. 12. Mitsui foaisu---13. Kurcka............... 11. Miscellaneous...... 13 11 5 19 14 7 5 5 4 3 2 3 2 10 5,40 - 4.250 2.350 6.333 5.G0D 3,o;o 1.730 1.330 1,110 400 630 610 410 2,400 107 35,540 Planned (1073-1031) VCM, Plants MM Lbs./Yr. 4 2,ISO 2 580 ---- 2 350 l 260' 3 1,050 3 1,730 1 , 500 1 250 1 330 ---- 1 90 ---- 1 330 20 - 7.6SO Oxychlorinsticn process provided by 5FC. of one licensor, B. F. Goodrich, lias been combined with direct chlorination and VCM technologies of others, i.e., Hoechst and Stauffer. Table 4 presents a tabulation of worldwide VCM producers. This summary was prepared from scores of literature sources, some of which, were contradictory. Howe.ver, the authors have exercised their best judgment in the absence of specific information from the listed licensers. The reader is referred to Leonard,54 GomL5C or Sittig55 for details of the acetylene and mixed gas routes to VCM. The technology discussion herein will be limited to the balanced ethylene feedstock route used overwhelmingly today. Although each of the major technology'' licensors lias many patents, none has complete coverage of each step of his process. As a result, the sequence and type of operating steps tend to be very similar from process to process. The basic differences stem from the oxychlorination technology and the types of impurities appearing in the crude EDC. The licensor, therefore, provides process know-how primarily, as opposed to patent position. As a result, published literature by major licensors is under standably very sparse and highly .simplified, with certain exception;;.55-5T'sS> 5U TYPICAL VCM PROCESS The typical VGM process combines direct and oxychlovjnntion (oxy) processes to provide 1,2-dichlorocthane (EDC) feedstock for the EDC pyrolysis unit (sec Fig. 4). The direct chlorination process relative to oxy is char acterized by low capital investment, low operating costs and high purity product. However, HCl generated from the EDC pyrolysis unit dictates the use of an oxy unit. With the current pyrolysis yield of approximately 0-55 mol VCM per mul EDC fed, and the HCl yield of 1 mol per ruol VCM, the oxy unit size is set at approximately 0.9 mol EDO per mol of VCM desired. Tins sets the ditcct chlorination unit size at approximately 0.3 mo! EDC per mol VCM. The combined EDC streams are caustic treated to rc- CCR 0 0 0 0 3 1 6 7 3 Fig. 4---Typical vinyl chloride monomer blcck/flow diagram. P'S- S-- Schematic of the Stauffer vinyl chloride monomer process .0... . March 19V0 ...................... .................. _ CCR 000031674 - SI TADLE 4---VCM plenty--worldwide--(cont'd) l!a?y A`.C Operator Rumijnci Sud . SAP? Sin:;l SoK.c Sir Ccnscrzlo Industries A:ht Penn Ch.sw Dn\( Ke-a!\U Japanese Geon KasJnmj VCM Witsubishi-Momanto Ryo-fiich* Co.. Ltd. Sar.jo Monomer Shunan Pirtr'-ehefpic3ls Sur^ctomo Sun Arro* f honical Toys C-cici To/o C;-Jj Korea r.itea Pacife Kstea Pacific Libya GAOI Pemt* Morocco SlitP liorway hsrsk Hydro Peru Sxudad Paratpanga LTDA. Poland Pciinisn-Cekcp Porluoii Rumania Industrial 1 rn port State Authority South Africa Allies Etflosives and Chemicals Spain Monsanto Vm.ctor 5weden Kerrjr.ci.-el Switzerland Taiwan Chun* Iji (?) Turkey PtUiffl PelVim United Kingdom * Location Ravenna fYrla Mjrghera C'gliari CuEliari Termir.i Imersee Proto Rjvjrnioo Porto Torres Chiba liiirumola Chiba Takaoka Takasara Kashina Yokkaiuhi Navoya Osaka Chiba h'jL'shirr.a f.tiziithims TckLiyama Tfkashimn ToLuy-ina C'fy Yekkax.-.i Yoo-Su Uisan Abu karrrrash Pejaritos Pajiritos Mohanimsdia Raines Paramor.ra Wicclo.vok Sines Rirr.nicu VV:a Rimr.icu YiJCJi f Sasolbur? 1 Sasoiuurg Tarragons TarrS'-ona TariK^una Morionell Huelva Stanungsund L? iefen Kachsiung Tutlea Yarir:c3 !::n,t Ah 0 fci-1 i.-n ir *- ICI US5.9 Teci'.mjshimpoit Venezuela Pitr;;.js YufCsIj v u Or/ ' fit. t .1 H-T..,k 1 t-.J Hilitcuse llurcom Di?r,msk til/i C - 'k i KJush '.< l "o^rod 2.UJ El TaiUro E<opj K:.'CVO Process Startup Y*ar * Licensor A/-/M/A/O M/A/U E/-/0 E/A/O AE/-/D . E/A/H M/-/D E/A/8 E/A/8 F/A/B M/-/D Af/A/AE/A/O E/A/B AF/A/O E/A/3 AE/A/O A/-/E/A/8 E/A/O M/-/0 E/A/3 E/A/B E/A/a E/A/8 E/A/O E/O/B * Planned E/0/3 E/-/0 AH- E/A/3 E/A/& A/-/r/n/R E/0/3/ E/-/1> AE/A/O A/-/- r/A/R E/A/3/ EA/-/0 E/A/B //A/3 F/A/B 1571 1970 ' 10A5 10/G 1957 2971 iOc.7 2959 3970 3979 1SS4 3970 3354 1579 3SS3 1970 3970 i"5S 1957 i?56 (1979) C19P0T i378 1976 1973 (1979) (1931) 19S8 1978 (3350) 3:,79 (J5J1) 3967 i:73 (iosi) 1973 i 9/6 is/i (i979) 3977 ' (i'-73i sr>ur?er BfG PPG rpc Ethyi SoU'ay Sir PPG Sla'jtfer Toyo Sada Japanese Geon Slaudor Sia'.'iter BFG Kurchs MilS'Ji Toctsu Mitsui icatsu Tcyo Seda BFG BFG Toku>3rna Sods Tokuy: tin Snda Tayo Gc:di Toyo Si-da Dow Dow BFG, Hoechst Monsanto BFG Stov.'fer . BFG, Ilcchst Vutaan PPG Do.y Mitsui Toatsu ICI, Suivay Tencecd Monsanto Marsjuia Monsanto So'.i ay Dl-.v Stauf.tr Sta- 'fi-r Mitsui Toaisu Soty.ny ICI, Solvay BFG Sotv-.y Sg.'w Rhone-Pie'll Stjwtler Ihhcnc-Provt) PI ti. ti )hst Kurena FFG. Hoechst BFG Phnne-Rf.'Otl Strutter Do.y Ertpinocr/ Contractor Foster Wheeler Opt, Salas Euteco Solvjy Eutcco Su-mtomo Hitachi Surndotno Kanssafuchi Cliiyada Toyo E'n-neerint! Toyo Er.ibnoenng Hitachi Hitachi Fluor/Daeiim Prccon F. Uhda, Saizgitter Lu.~rr.us Hulsla lucks , Badger Petrocaibon, Davy-Powergas Kicck Toyo Engineering H-jrnr .ies & Glasgow Crjuierd-Kpsuel Lunsmus McKee, CTIP McKee, CTIP McKee, CTIP Lurgi Huirphreys and Clasgow CTIP C. F. Braun C. h Braun SpjpCt'.im Srsishitn S;:^'Chnn f. Lhdc ChiyGii J f. Hide foster Wheeler VCM Capacity, MM t.bs/rr'* 155 359 350 (110) 130 > 310 99 350 220 (330) 257 331 331 770 v 265 130 130 73 <40 238 1PD 220 no (330) 132 (136) 155 440 59.. jt 660 17 (450) (330) ES 350 60 440 17S-330 (250) 530 220 (500) 256 (770) 180 44 530 (530) 119 ' (257) 573 es 73 65 550 115 (505) no no (270) (410* V I - itnjn t i'.'jI 1>I frr-s n inf 5 jure* v 111 O'.'S i'l'Mii cJ c-j ! f ldct.rr ffiO'li. v,|kon h 1*0 e#ru'.e 1 ?h*,r It .{ i.Jgr.ient. ' i'j'enthescs uenulI Injr ; I >n! ,; t.n ,u<nl IJ 1.9 n .< or 12 istfuctign :t !?* j.'J f. J* i',,t icot"ieJ an <Yi jlun Jl status. legrndt l yC.jta'kon feedstock / CiyRasiS / Process (i :ir>-.9 fA'CrUI*:!* (M>nj r {U'jfies'J (0)r [Ujir.'Ct CCR 000031675 VINYL CHLORIDE MONOMER TABLE 4--VCM plants--worldwide Operator Uriled States ICI An-fnr* Cuuoeo Ci fl'nic.^fj Dow Cthyl Corp. B. F. Goodrich PPG She II Chemical Slaulfer Borden Chemical Georgia faritc Diamond Islia:nrock Algeria Scnilrach Arp*fl1i|>* Dow Qgir.tiu EletUCClbi Australia Iciana Deir'um EASF LiLcshern limburgs; iLVM) Sclvtc Brazil Cooamo Monomers Vimtico? Pelrouu.M Camion Bulgaria Ttehrocampfckl Canada Dow Shav/inigan Chili* Dow/H.AP China Tcchncat Impart Corp. CdoThis PeticjumuM Columbians Ceche-'3vaki* Chtmoi'-ttrci Ch-emir.kcaavouy Pit;! a Finland ' PK<na Oy France AKZO Cho in'* EVC/OSM [),'.Lilac (ihe-ne-i'erkne Sslvie PC'JK/Sheli Cher,lie Cast C.-rruny Industrie AMugen Import West Germany Alusuiose Hull Solvay Dynannl Kcbcl Hwc.'iit Knapsack, AG Wicker ICI Criice Linyl HallJl Holland Ali/O Huethsl Shell/ Kunp.ry Cliemoi'.ca'picx Cowsodi Vegji Kom6in.it India CiP 1 r.d,a halional Organic Chemistry Iran Abadan P-itrothemical lia-:-Jaj,--n J V. Iri-i L UIq Israel UlihTnic*l Industries Locatinn Baton fioure, Louisiana lake Charles. Louisiana F reef art. Teias Oyster Creek, TeiiS Bai:n Kuu?c, Leuin'ina Kguslon, Texas Czireit City, Kentucky - lake Charles, Louisiana Lake Cher!"*, Lcuisiana Gu?j?nilla, Puerto P.ito Deer Park, icxas tic;CO, Louisiana Lone Elaach, California C.iiismsr, Louisiana Piaqueminc. Louisiana Deer Park, fexas > Skikda Bahia Blanca Capi'sn, Dcrmudez Oshia Blanca 60`crry Anvers leluy Tcssendcrlo Jemeppe-Sur Color hshia Elenca Cansacari Burgas Devnya Scrnn, Ontario Varennos, Quebec Shawifujan, Quebec Concepcion Peking Ntretance fiovaky, Slovakia Porvoo Con.'rcville It Havre Olimarsheim Jairii Lavera St, nuusn st. r-.n Tavcux fosSurh.er Schkopaij Wilhtlmuhnveti Id 3*1 LuCwivshiven Jfhfi.Vjcig Cu**. ^ ;rf Cer.dcrt AnJprark Vi-suingen Knapserk Knapsack B.i:rhuscn Burc'iausen V.V/.elmshavsn Ti-etsalonika Butick Botiv-' itipansion) Vii$'...i 'en Perms I'ereMe tirrentc Ka:ir;L,srctkJ Mad,a* lnjn.biy AhjKsn L'aniUr Basra lis.'a Akr 0 1 * H\mor.;'un.M- I1ir.r V- k v'vr Process r/A/R E/A/8 E/A/O F/A/O A/-/E/O/B E/O/B E/0/3, E/A/B/ E/A/a E/A/3 E/A/8 E/0/8 E/A/6 E/0/ 8 E/A/8 A/-/D E/A/9 E/A/B E/A/8 E/A/B e/a/b E/O/B E/A/B A/A/0 E/A/O E/A/t1 E/A/B MHO E/A/B M/-/0 E/A/B E/A/O E/A/B AE/-/0 AE/-/D E/A/8 E/A/O C/A/O Er./A/O r/A/o t/A/U C/-/0 * C/A/D E/A/D E/A/8 f/-/o A/-/f/a/u I/A/3 E/A/8 Starlirp Year** 1938 l?o8 i'C9 197* I?S4 issi (19601 1971 1972 1272 1957 (iisdi 1278 (1979) 1967 1972 !976 19CS 1372 (i979) (1979) (i979) 19S7 19C9 1978 1973 1972 1972 1971 K6? iS70 1335 (ISSO) (IS79) 1973 1956 IS72 1`jCi i97i (1980) 197] (1579) (MSI) i9?a l$7 19<9 ns;?) -(1590) (1979) Licensor BFG Slaufler Dew Ethyl Ethyl BFG PPG PPG PPG SIouGcr Stou'fcr Stauf/cr Stau.'.cr PPG Stauffer, BFG Mitsui Toalsu Dow ICI BPG ICI Stauffer BFG Ho;ehst, Brc Hoeilitt, UFG Ethyl So'vay. ICI BFG BFC PPG Ennlnecr/ Contraclor ft, M. Parsons Ford. Bacon & Davis It. M. Parsons Fluor R. M. Parsons ft. M. Parsons C. F. Braun R. M. Parsons Brown and Rent Lummus, Badger, Brown & Root Toyo Engineering Cheniico Badger BASF Badger Badcar Solvay McKee, CTIP Badger Badger/Promon Teehnip/TPL BFG BFG B. f. Gocdrich Stauffer Slf.utfer BFG, hcachst Solvay Rlaiificr, 6FG. r-lojchsl Pi'one-Pro'.l Rhcr.-vPro.--l Solve/, iffiyl BfC Hoechst Badger Fisti Engineering F. Uhdc ft. M. Parsons, Voesl, Alninc F. Uhdc CUP fthono-Progil Phono-Progil Solvay Badger F. II h do Luts Slaulfer Solvay Stauficr, BFG urn, Kc.chst UfG, tic-echst BFG BIG SlauHer/Staoiler Wacker ICI Ethyl S!au!ler/OFC Hoechst r Solvay C. 1. L'raun Of.Je Badger. Uhdc Cjapcr, LH:de Goover, Knapsack R. M. Parsons R. M. Parsons Fluor Comririnio-I.urei AK70 Engineering VCM Capacity, MM Lbi/1r'* 303 700 203 700 1,150 300 150 1.050 300 400 (1,05-0) 503 840 700 175 330 (1.033) 1.003 (88) no 73 287 T 240 (1,100) 440 440 550 220 (2S6) (320) (330) (680) 126 126 35 176 265 240 68 - 440 795 291 440 440 (440) (440) (660) 700-770 160-320 440 130 375 220 (*4C) 220 330 176 350 (680) 33 tco (330) (350) Hoechct HTG, H.-nchst brn. Mecch.t BFG Shell, BASF arc Toyu Suda SlauGer F'on.in'.o Wide Badger B.ilr^r, Lummus Hitachi L'.nirnuj, Thysson . * * 79--- 350 35a- 33 45 130 > (330) 145 29 (270) CCR 00003X676 ___ ..as .r 'si.v VINYL CHLORIDE MONOMER move HC1 and certain clorinated byproducts which otherwise would hinder fractionation or pyrolysis. The "clean" EDC is subjected to distillation steps in which water and oLher light components are removed, as well as heavy components typically labeled tars. The dry product EDC, generally of 99.5 percent or greater purity, is thermally cracked to yield HC! and VGh.Tn an EDC carrier stream. Further distillation equipment separates EDC and HC1 for recycle and yields product VCM for final treating. The typical VCM plant includes VCM treating offgas treating, light ends/tars handling and waste treating facili ties. It will also include incineration units for reclaimin'? waste chlorinated hydrocarbons from offgas or liquid streams.1 heat is removed by generation of steam on the shell side of each reactor. The final reactor effluent is cooled to condense EDC, and the offgas is contacted/reacted with chlorine to recover ethylene as additional EDC. The offgas stream is cooled versus cooling water and refrig eration to further condense EDC before exiting the pro cess. Residual ethylene concentration in the vent gas is reportedly as low as 10 ppm.01 Stauffer also offers an oxygen-based oxy process (Fig. 6) in which the main reactor offgas, following condensa tion of EDC, is compressed and recycled to the first oxy reactor. An excess of ethylene is used to maximize HCI conversion and minimize byproducts. A small slipstream from the ethylcr.e-rich recycle is purged to an ethylene recovery unit for control of inerts. Stauffer technology.00'111 In the Stauffer direct chlori nation process (see Fig. 5), ethylene and chlorine are reacted, in the liquid phase and under controlled condi tions, to yield a crude product which analyzes 99.7 per cent EDC. The reactor product is then combined with the crude oxy EDC, washed and distilled lo remove water, light ends and heavy ends. I'mc EDC is preheated in the economizer of the pyrolysis furnace and then vaporized with steam. EDC vapor is then heated to dissociation temperature in the furnace tubes to yield a mixture of vinyl chloride and hydrogen chloride. Conditions are controlled to maintain EDC conversion at 50 to 55 percent. Following a quench . ami condensation step, IIG1, VCM, and uncracked EDC arc separated by distillation. Ilv.lrogen chloride gas is sent to the oxy section. Unrcactcd EDC is recycled to purification. V The oxy section combines recycle HCI with fresh ethyl ene and air in tubular fixed-hod catalytic reactors. The ethylene and air aie fed in excess of stoichiometric re quirements to assure high IIOI conversion.1:1 Reaction Ethyl imso?u!sd VCM process.02 Gaseous chlorine and ethylene are introduced into a direct chlorination reactor in which they combine to form EDC. The very high purity EDC product can be sent directly to (or, after degassing, can bypass) the EDC purification system (see Fig. 7).' Air and gaseous ethylene and HCI are introduced into an oxychlorinatton reactor in which EDC is produced at an elevated pressure and temperature in the presence of a fluidized catalyst. The reaction products arc neutralized and partially condensed to recover EDC which is first sent to a drying column and then to the EDC purification system. A portion of the vent gas, consisting primarily of nitrogen and carbon dioxide is recycled to the reactor for added safety. The purified EDC stream which contains recycled EDC as well as the EDC from direct and. oxyrhloi inatiou is vaporized and introduced into a furnace. At least half of the EDC stieaui is cracked to HCI and VCM. The reaction'products are cooled rapidly, partially con densed, and then sent to the VCM purification system. CCR 0 0 0 0 3 1 6 7 7 Direct cMorin.ition Oxyehlcrinalion Fig. 7'--Ethyl Corp.'s integrated vinyl chloride monomer process. HC1 and VCM are separated by fractional distillation from the unconverted EDC and small amounts of by products. The EDC, containing the byproducts, is re cycled to the EDC purification system. Mitsui Toatsu Chemicals technology.*8 The MTC technology utilizes a boiling liquid process for the direct chlorination reaction. Reaction .heat is dissipated with the gaseous EDC exit stream which is condensed externally and sent to purification. The oxychlorination process is characterized by trie use of oxygen feedstock and a fluidized bed reactor. The reactor effluent gases are quench cooled with circulating EDC followed by caustic neutralization. The neutralized gas is cooled to condense EDC and water. Uncondensed gases, primarily ethylene, are recycled back to the cxy reactor. A small stream is vented from the recycle gas to allow purging of inerts. EDC liquid is phase separated from water and dehydrated before joining the EDC streams in the purification system. A conventional EDC purification system splits crude EDC into light cnds} heavy residue and pure EDC. The latter is cracked to yield VCM which is purified in a manner similar to that described in the Stauffer tech nology (sec Fig. b). PPG technology.03 The EDC production technology appears very similar to that described for Mitsui Toutsu, particularly in the use of oxygen feedstock am! fluidized bed reaction for oxychlorination. However, PPG does not indicate use of a dehydrator to dry crude oxy EDC prior to purification. Also, PPG uses three rather titan two towers to obtain the HCI-VCM-EDC separation. 3. F. Goodrich technology.07*70 Goodrich direct chlori- - nation uses conventional water-cooled technology similar to that shown for StaufTer. The air-based, fluidized bed . oxychlorination technology is similar to that shown for Ethyl. Goodrich also utilizes an absorber-stripper system on the cxy vent gas stream to minimize hydrocarbon losses. Goodrich, in conjunction with Cadger, Inc., offers complete technology for waste treating of VCM plant effluent streams. Toyo Soda technology.5*'07 This technology appears very similar to that offered by StaufTer. The principal differences are in the use of an absorber-stripper on the oxy vent gas effluent (as with Goodrich) and the de hydration of crude EDC prior to purification. As with other oxychlorination processes, steam generation is used to remove reaction heat. Phona-Pculenc technology as*n Rhone-Poulcnc offers two processes, Chloe I and Chloe II. The former is of a special nature5* to yield concurrently significant quantities of other chlorinated hydrocarbons such as trichloroethyl ene and trichlorocihane. The Chloe II process is "true" -JVCM technology using air-based, fluidized bed oxychlo rination in combination with boiling liquid direct chlo rination. v Monsanto technology.7* This process appears very simi lar to that offered by Stauffer. , CCR 000031678 HyntiOCAKPON Pkockssing March 1079 ____ _ .. . .. . : .85. VINYL CHLORIDE MONOMER DOW technology. Dow's technology has not been pub licized. It has been used only by Dow and its foreign affiliates. HEW DEVELOPMENTS Although it is believed that several VCM producers currently use boiling liquid reactors for direct chlorina tion, Stauffer has developed a unique application of tills concept.60 Their approach, "High Temperature Chlorina tion/' in effect uses the reactor ns a reboiler for the con ventional EDC purification system (see lug. 9) Purified EDG is withdrawn as a side stream from the tower, and any light components formed ate removed overhead. Normal feed to the tower consists of treated K1)G from oxy and recycle. Small amounts of the normal heavy ends or tars are purred from the hme of the reactor. This ap plication eliminates approximately 10'.),GUO lbs. per hour of 150 prig steam consumption for :i oiw billion lb. per V >onr VCM plant. A similar energy savings is achieved in ' reduction of cooling water usage relative to a conven tional leactcr and light ends tower. B. 1'. Goodrich73 also offers a i/oiiing liquid process in which the. heat of reaction is utilized to purify all EDC processed in the purification train. Increased activity by EFA (U.S. Environmental Pro tection Agency) and state agencies in regulating liydro- Fig. 0--Stauffer high temperature chlorination and clhylono dichforitJa purification schematic. carbon emissions are likely lo stimulate: further new de velopments, particular])- in oxychlorination processes. These will range from development of new oxygen-based technology In various add-on systems for cleaning up oxy vent gas. The latter may include catalytic oxidation, in cineration (of oxvgen-based oxy vent gas), solvent absorp tion, combined refrigeration and absorption techniques and/or oilier combinations. Several companies not active as VCM producers are involved in developing these add-on systems. It is expected that companies will continue to devote considerable effort to the development of cracking pro moters and inhibitors of side reactions in pyrolysis chem istry'. Current cracking practices limit EDC conversion to 50-60 percent. Considerable energy and- cost savings could be achieved througoh increased conversion levels without concurrent losses of EDC to undesirable side reactions. The net eO'rct of these various regulations has been to increase substantially the scope of add-on technology In VCM plants, such as: Installation (if primary and redundant incineration facilities for VCM point (cx oxy). source and collected fugitive emission-; Installation of HCl scrubbing and neutralization or recover)' units in conjunction with the incinerators e Installation of closed process sewert, collection sys tems and larger or redundant waste water strippers Replacement of single mechanical seals on pumps and agilatoj-s with double mechanical seals. (In some cases, conventional pumps were replaced with canned or magnetic drive pumps) Leak detection systems and portable monitors EPA regulations. EPA's "Standard Support and Envi ronmental Impact Statement: Emission Standard for Vinyl Chloride,"1 presented the following regulations: Emissions from all point sources except oxychlorina- tion would be reduced Lo 10 ppm VCM by volume Emissions from the oxychlorination reactor would be reduced to 0.02 lb. VCM per 100 lbs. EDC product from the oxy process Preventable relief valve discharges would not be permitted , Fugitive emissions would be minimized by requiring enclosure of the emission source' and collection of the emissions. ,, EPA estimated typical VCM plant emissions in 1974 as follows: Lbs./VCM/ Source 100 Lbs. VCM Fugitive 0.1215 EDC Finishing Column 0.05 VCM Finishing Column 0.24 Oxy Process 0.0364 Process -Water 0.0007 Total 0.4479 The regulations were predicated upon reduction of such emissions by 54 percent using best available technology. Compliance testing of these installations was begun in the last quarter of 1978. Additional EPA and stale actions were initiated in mid-1977 to reduce hydrocarbon emissions from VCM plants in non-attainment regions, i.c., much of the Gulf Coast. EDC production is reported to account for 23 percent of the hydrocatbon emissions in the southern Louisiana and East Texas AQCHs,ir- These actions were directed primarily against oxychlorination vent gas from air-based units. The amount of hydrocarbon reduction sought varies from region to region. N'o published guide lines are currently available to reference. Enclosed sampling and analytical systems 9 Vapor recovery systems for VCM loading/unloading and equipment clearing. The EPA report estimated a maximum capital impact of $0.8 to $1.9 MM (1975 dollars) for a "model" 700 MM lb. per year VCM plant. Recent cost estimates in dicate the true impact for these items is nearer $15 MM based on 1973 dollars. Addition of hydrocarbon compli ance (proposed regulations) may add another $2-$5 MM. EPA also has proposed further reductions in VCM emissions.05 Under consideration at present are regulations which will reduce allowable emissions from 10 ppm to 5 ppm for all point sources, including oxy vent gas. EPA further plans to prohibit emission increases within 8 kilometers of an existing source due to construction of a new emission source. This will effectively prevent expan sion of existing facilities or construction of new plants in the vicinity of ousting plants. The proposed oxy vent gas regulation will also dictate substantial capital expendi tures for add-on facilities and possibly the conversion of air-based to oxygen-based plants to facilitate incineration of tail gases. ECONOMICS Table 5 presents a 1981 manufacturing cost buildup for a typical 700 MM lb. per year grass roots VCM plant. Raw materials total 12 cents per lb. VCM or 54 percent of the required FOB plant selling price. Capitalrelated costs amount to 6.8 cents per lb. VCM or 32 percent. Utilities are. only 6.7 percent of the total VCM cost. In perspective, the 1972-1973 reported VCM selling price07 was only.-4-5 cents-per lb. By 1981, the capitaljelalcd unit costs alone will exceed this by 50 percent. The obvious major factor in VCM pricing is raw ma terials cost. Although chlorine price is expected to double between 1973 and 1931, the impact of ethylene price will be evert greater (three cents per lb. versus 17 cents per lb.). The real culprit, of course, is crude oil cost. During the kite 196CL and early 1970s, plants using inexpensive LNG feedstocks were significant contributors to the low cost U.S. ethylene supply picture. The energy crisis rap idly reversed the low cost feedstock trend. LNG scarcity HynKocAkvoN P ocrr.sixc March 1979 OCR 000031680 07 VINYL CHLOniDL- MONOMER dictated construction of naphtha and/or gas oil crackers for present and future ethylene production. This tied VC'S l prices irreversibly to crude oil pricer- through ethylene, fuel and power (particularly via its impact on chlorine). ACKXOVtLLDr.MF.NT5 TLe .i-ilhc-rs gratefully aeknox1-rire contributions by A. B. Stryker, Jr., of Mauitcr and II. JI. ei F.thyl and ^ermbsion by their companies to ue die information presented on their respective processes. LITERATURE CITED * U.S." Environtcenu'. Protection Agency Report No, EPA-i50/2-75-003, Research T.-iansJt lark, N.C., (1973). I Leads, H, S., (ta Monsanto Chemical Co.) U.S. Patent 3,333,932 (1967), > B. F. Goodrich Co-. British Patent 1,233,23.5 (1971). <Cat3pbeli, R. G-, (to St3ufter Chemical Co.), U.S. Patent 4,C!X),205 (1976). * Benedict. D-, (to Union Carbide), U-S. Patent 2,929,352 (1960). * Di Fi.-re, L., and Ctlcagao, B., (to Soc. ltal. liesine), U.S. Patent j.SH.UjS (1975). Tsao, U.. (to Luacuj Co.), U.S. Patent 3,917,727 (1975). * Kurtz, It. D.. nud Qmehan, A., (to Allied Chemical Co.), U.S. Patent 3.9U.5E3 (197P). * Vulcan Materbis, Briti-b Patent 930,933 (1265). t' Van Arit'.*rrp, A. C., Ifurpritttr, J. V/.. Stcrbtnj. R. G-, and Kang, T. L., (to it. F. Ccodnrii), U.S. Patent 3,103,323 (IS.'O). " Severina, F T.. (:o SlvLYer Chemical Co.) U.S. Patent 4,06.522 (I1?//). Stauffer Chemical Co., Lr;t:sli patent 1,236,637 (1971). s>-B. F. OorCricb Co., Belgium Patent CSO/illi (IlroS). l*KiLa, H., (to Mitsui Tcotsu Chemical), Japanese Patent 46-43367 (1971). II Mivaaahi, IP., (to -Mitsui To.iuu Chemical), Eruiih Patent 1, 199,815 (1970). * Takahiilti, T., (to Miuui Toatsu Chemical), Japanese Patent 45-32406 (i9:o>. Mitsui Tcauu Chemical, Jjpaisete Patent 45-33010 (1971). 11 I*PC!. Industries, Fr-r.cb Patent 2,COO,Get? (1271). *>Muen. A. (to PPG Industries), British Patent 1,220,334 C.97i). s' AJjljtroai, Jr., R. C-, (to Dow Chemical Co.), U.S. Patent J.KB.SCl* (19)5). ;,Sinni. J. C-, and Ccsies. J. R., (to Khone-Progil), U.S. Patent 3,935,285 (l`J7o). Aboui the authors Robert W. McPherson is products manager, Continental Oil Co., Houston. He is responsible for the worldwide profit performance of Conoco's chlo rinated hydrocarbons and their strategic development. Mr. McPherson received his B.S. from Corv.ell University. Charles M. Starks is director of explorutoni research, Continental Oil Co., Ponca City, Okh:. Dr. Sfarks received his P.S. from the University of Okla homa and hii PhD. from .'hi.-;<ac!nisetts Institute of Tcchr.ology. t/JV rt uA Galvin J. I'llYAR iit su-perxdring process engineer with Continental Oil Co., Ponca City, Qhla. He is rf'e;<?/'st7W(j for the super v i ion of process designs, technical canxvlting and cr'jyiof'iics for rhvw'cuM processes. .Mr. Frjnr tvc* ived his P..S. i'i t/n;mtrnf enginerring from the University of AVtw Mexico. TABLE 5--HsSiniated 1981 VCM manufacturing cost Raw M.iten'b Lhs/Uj VtM 064 0.49 ^/Bnit 5.6 17.1 Cost. */Lb/ VCM 3.53 1.42 13.79 1.13 0.63 2116 15.95 5.35 21.79 % 15.2 1.8 6.5 63.3 5.4 4.5 9.9 73.2 26.8 100.0 Bases: 1. J20 MM Pounds/Year Balanced VCM Plant. 2. 1531 Startup 3. Grass Feats lir-estment = JKO MM. 4. L<;ht aaJ |:-3vv e<v.i> ir.cinaraled; recovered Pci sold as muriatic add to break even on irc-incra'iion cccts. 5. fiftenn percent DCF rate cl return 1a cover mte-esi charfes and profit. 6. Unit values arc generalised and are not spcci-'-c to a particular lissnsor or technology. 53 Smalley, E. )V., Kurd, 11. E., and Bandyor>adhyay, B., (to Allied Chem ical Corp.), U.S. Patent -UolViOO (1077), 23 Knonsjck Co., British Patent l,2CGS.0Jn (1972). Seivav cl cic, Frei.cli Patent 1,6-32.522 (1971). 33 KtoVeler, A., (to Kr.; r.-.-yk Co.), bJ.i. Patent 3,424,493 (1969). 3,4 J.icklin, A. G-, (to ICl), P.rnLh Patent 955.618 (1964). 35 A'roelich, W., (to iincchst), German Patent 2,217,694 (1973). ts Barton, D. H. R., J. Chon. Soc., 149 (1949L " Ynuriv, D. P., (to It. V. Chemicals, Ltd.), U.S. Patent 3,095,182 (1575). Ju Mitsui Gkt.-.Jca; Irctiustrivs, jao.inesc i'aler.t 42-22921 (19G7). 51 B. l\ G'-o<lrich, British Patent PJ3X24 ilOGJ). ,J Knaj, ack Co., U.S. Patent 3,475,555 (19b'J). ** Monsanto Chemical Co., Biiush Patent 1,163,329 (1C59). ''Keating, ll. J., \io A'onsanto Chemical Co.), U.S. Patent 3,125,GO/ (1964). " Ga.isc, L. hi., (to Mo"ianm Chemitr.-l Co.), U.b. 1'a tenr 3.142,709 M McDonald, D. W,, (to 7.1onsanto Chemical Co.), U.S.M'.went 3,125,603 05t>4). ,3omi, S., F.ightli World Petroleum Conjtrcsj, Proceeding* #, 371 (1971). '* Kureha (lli^micil industries, BriLish Patent 977,573 (1964), British Patent 1,658,753 11L'!;7). " Lart.-n, D. H., ai.il l.lu-^dan, 5-t., J. Soc CItcm. Snd, (Lc-nelon), 69, 75 (1057); Pamt, l',, and W.-idliaii, I'., Ildo. Chin. Acta., ,?2. 703 (1945). "Gornnr, R. D. and Starks, C. M., (to Continental Oil Co.), U.S. Patent 4,046,823 (1977). " Kuck, M. A., (CO SUufTer Chemical Cn.), U.S. Patent 3,937.118 (3976). <J WinMeln, N. J., (to Princeton Chemical Research, Inc.), U.S. Patent 3,551,356 (1970). _^ ** Kurtz, B. E., Smalley, F-. )V., Soimosnaan, W. F.., and Van Atta, J. P,., (to Allied Chemical Ct,.|i.), U.S. Patent 3,387,119 {19/61- "Gor<lv-,n, T. H., nncl Kuunncrle, IE. P., (to Ovrene-llliauis, Inc.), U.S. Patent 4.042,tJ'PJ (13;2). P.icsel, H.,(to l.uaimii* Co.), U.S. Patesst 3,750,(741 (1974). Rieicl, H., (t.1 Luntiisu* Co.), U.S. Patent 3,557.223 (PJ71). 'r Rieed, If,, (to Ljiiitnui Co.), U.S. Fat-iit 3,937,7 14 (1970). *' Sre, M. C., (to Lumnui* Co.), U.S. Patent 3,946,011) (1976). " Y'sao, U., (to huinio'jj Co.), U.S. Patent il.Vo'j.'Cn (!97<i). `a '1's.io, U-, (lo Lun:cius C--.), U.S. patent 3,592,-If*0 (1976). ** Rirgel, H,, (to Luminus Co.), U.5. Patent 3,935,2Sfi (1976). i3*fsao, U.. (to Luuiaius Co.), U.S. Patent 3,985.316 (J97G). 81 Mii.ot, J. 1)., Cb.cm. Kn,:. lOogt., GO. (fl), 71 (1973). ''Leonard, 11. 17,, l'i/:>/ end 77/eii* ji/onomert (Part 3), John 1Vi Icy and Sous, It-c,, New York, 1971. ''Sittitr, I'l'atf Chloride end PVC /fantj^nffure, Noyes Data Coip., 1978. MComi, 5., "/a/'rt.i't .Yea.- kb-tM' C/.r-'iVe l'rott>i (Kurit-ti)Hydrocarbon I'roieuin*, Vol. '13, No. II, November 19*31. *" Ko>enz%eii', M. D. /`Vinyl I'rcti't lias Wirle Ranee of liy-Producl*,*' ( Rhone-Prn;;il), Chemical Er.-jin rer.'.t", Vr,! 78. No. 2r, tlct. HI, 1971. " Robert. J,. and Brrrlcr, A.. "Rhone-Fro-til Ncv Processej for the Manu facture of Vinyl C.hlnri<tu 'don<trj;r and Chlorinated Solvents from Llhylene," Hrlth A.C.S. National MeeCiuv, Neiv York, Any. 27-Sej/t. 1, 12*2. *' I'.iicLley. J. A.. "Pr-ycti Plo'v Sh-ct/Viivyl Chlivitle via Ditect Chlorina tion .Mid Cixytldoriiiauon," Chemical Engineering. Vol. 73, No. 21, Nov. 21, 1366. _' ** Piiv.itc C.otiitiiunication from A. E. Stryker, Jr., Stauffer Chemical Co., Nov. 29, pj:3. *' llrirlr, Peter, "Air or Oxy*n for VCM?" Ilyydroecttbon 1'rocetAng, March, 197t">, C5-89. *3 Pi Ivyte Cuiiiinuniratin i from If. If. Wall, Ethyl Corp., Nov. 28, 1978. 41 Vinyl Chloride, "ilidt'aort'rn Procming, Iov., 1975. M Kr>A-4.)0/3-7i.U.vt:i \'.l- 3, NovemLier, 1971. 44 t'cl'rnl June 2. 1977. Fi*A-y.'.7/2-7i-h VJ, Ma,rh, 1976. *' Kra-ie, David P., rt al. "Vinyl Chtmide: How, Where, Who--Future," //>i/ni(<jrh'.>n i'roeeuing, l ihruary, 19<3. *'"Vi.ivl Chh-ride--Miimi To.itsu Cliemi.aU," Hydrocarbon Prorating, N't>* vrmhrr ''"k'nvl Chloride--PPG Industrie*, Inc.," Hydrocarbon Proceuing, Novetn. bet P/75. 'Vh.v! Chlori-I/- -11. P. Oooslrieh Chemical Co., Hydrocarbon Proceuing, Nr**er:l>re l'a/ t. ' '\'ia>l (d.hirul-- Uhoiiie-pnulenc S.A.," Hydro a'bon Protecting, Novem ber rj75. " "Vinyl Chloride--(Monsanto Co.)," Jlydratnrbon Proceuing, Novemlier 1975. ''Piivjte rv>innniiiia(ios from J. S. Denton ft, , Cootlrirh Cl/emiral Co.. J .n. 5. I"r9. U CCR 0 0 0 0 3 1 6 8 1