Nkag Siab Txog Cov Txheej Txheem Vinyl Chloride Monomer
Vinyl chloride monomer (VCM) yog lub hauv paus tseem ceeb ntawm kev lag luam yas niaj hnub no, muab cov khoom tseem ceeb rau kev tsim cov polyvinyl chloride (PVC). Ua ib yam khoom siv tshuaj lom neeg, VCM tsuas yog siv rau PVC polymerization, uas ua rau muaj peev xwm tsim txhua yam los ntawm cov khoom siv kho mob thiab cov ntaub ntawv siv rau cov hlau txheej thiab cov khoom siv rau cov neeg siv khoom. Qhov kev thov rau VCM muaj feem cuam tshuam nrog cov khoom tsim tawm PVC thoob ntiaj teb, ua rau nws muaj kev nyab xeeb, ua haujlwm tau zoo, thiab muaj kev nyab xeeb ntawm kev lag luam tseem ceeb.
VCM yog ib qho roj tsis muaj xim, yooj yim hlawv thaum muaj huab cua kub, feem ntau siv ua kua dej uas muaj siab hauv cov chaw tshwj xeeb. Nws cov qauv tshuaj, CH₂=CHCl, muaj ib pawg vinyl txuas nrog ib qho chlorine atom. Qhov kev npaj molecular no tso cai rau kev polymerization yooj yim, ib qho kev ua haujlwm reactivity uas txhawb nqa cov tshuaj vinyl chloride polymerization tseem ceeb hauv cov kauj ruam txheej txheem polymerization PVC. Cov khoom siv lub cev ntawm cov kua vinyl chloride—xws li lub ntsiab lus kub ntawm -13.4°C thiab qhov ceev ntawm 0.91 g/mL ntawm 20°C—xav tau kev tswj hwm cov txheej txheem zoo thiab cov txheej txheem khaws cia tshwj xeeb uas tswj cov tshuaj ua kua rau cov txheej txheem tsim khoom vinyl chloride monomer.
Cov Txheej Txheem Vinyl Chloride Monomer
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Kev siv VCM sab nraum qhov ntau thiab tsawg ntawm PVC yog qhov tsis tseem ceeb, qhia txog nws lub luag haujlwm ua ib qho monomer tshwj xeeb rau polymerization. Yog li ntawd, txhua yam ntawm vinyl chloride monomer cog tsim, los ntawm reactor tsheb ciav hlau layout mus rau cov khoomkev ntxuavthiab kev rov qab los, tau ua kom zoo dua rau kev hloov pauv loj, txuas ntxiv mus rau kev muab cov thev naus laus zis PVC polymerization.
Txawm li cas los xij, kev tuav thiab khaws cia VCM muaj kev phom sij heev. VCM raug cais ua Pawg 1 carcinogen, nrog rau cov pov thawj muaj zog txuas nws rau hepatic angiosarcoma thiab lwm yam teeb meem kev noj qab haus huv tom qab raug ntev. Nws cov qauv tshuaj lom neeg tau ua rau muaj kev tsim cov metabolites reactive, uas khi cov macromolecules cellular thiab cuam tshuam cov txheej txheem biological. Kev raug mob sai sai ua rau muaj kev nyuaj siab rau lub paj hlwb, thaum kev raug mob ntev ntev hauv kev ua haujlwm cuam tshuam nrog "vinyl chloride workers' disease" - ib qho syndrome uas muaj kev puas tsuaj rau daim siab, cov tsos mob zoo li scleroderma, thiab cov pob txha raug mob. Cov kev txwv kev raug mob yog nruj heev: txij li xyoo 2024, Occupational Safety and Health Administration (OSHA) teeb tsa 8-teev kev txwv kev raug mob ntawm 1 ppm, nrog rau cov qib qis dua uas ACGIH thiab NIOSH pom zoo kom cuam tshuam kev nkag siab txog kev lom neeg.
VCM kuj tseem kub hnyiab heev, nrog rau qhov tawg ntawm 3.6% thiab 33% hauv huab cua. Kev sib xyaw ua ke ntawm kev lom thiab kev kub hnyiab tau ua rau muaj kev ntsuas kev nyab xeeb hauv txhua qhov chaw tsim khoom VCM. Cov kab ua haujlwm raug kaw tag nrho thiab tswj hwm hauv qab huab cua inert - feem ntau yog nitrogen - nrog rau kev kuaj pom qhov xau tas mus li thiab cov qhov cua thaum muaj xwm txheej ceev. Cov pa tawm hauv zos, qhov chaw kaw cov txheej txheem, kev txwv tsis pub qhib hluav taws, thiab thaj chaw nkag mus tau nruj me ntsis txo qhov kev pheej hmoo. Cov kua VCM raug khaws cia thiab thauj mus rau hauv qab siab hauv cov thoob dej uas tiv taus xeb, feem ntau ruaj khov nrog cov tshuaj polymerization inhibitors xws li phenol los tiv thaiv kev ua xua txaus ntshai.
Cov Kev Tsim Khoom VCM Tseem Ceeb
Kev tsim khoom VCM feem ntau yog siv ob txoj hauv kev lag luam: kev siv chlorine ncaj qha thiab kev siv oxychlorination. Ob txoj hauv kev no yog tsim thiab hloov pauv ethylene dichloride (EDC), uas yog cov khoom siv nruab nrab tseem ceeb uas tom qab ntawd raug tsoo kom tau VCM.
Hauv txoj kev chlorination ncaj qha, ethylene reacts nrog chlorine roj hauv cov txheej txheem kua exothermic heev, feem ntau dhau ntawm ferric chloride lossis cov catalyst zoo sib xws los tsim EDC ntawm:
C₂H₄ + Cl₂ → C₂H₄Cl₂
Xwb, cov txheej txheem oxychlorination sib xyaw ethylene, hydrogen chloride, thiab oxygen siv cov catalyst tooj liab (II) chloride, tsim EDC thiab dej:
C₂H₄ + 2HCl + ½O₂ → C₂H₄Cl₂ + H₂O
Txoj kev no muab cov txiaj ntsig zoo rau kev lag luam thiab cov khoom noj khoom haus los ntawm kev siv HCl rov ua dua tshiab thaum lub sijhawm tsim VCM, uas yuav ua rau muaj teeb meem pov tseg.
Thaum EDC raug tsim ua ke, nws raug cua sov tawg ntawm kwv yees li 500 ° C, feem ntau nyob rau hauv theem vapor hla pumice lossis ceramic packing, los tsim VCM thiab hydrogen chloride:
C₂H₄Cl₂ → CH₂=CHCl (VCM) + HCl
Cov khoom VCM uas tawm los ntawm lub cub tawg yog sib xyaw nrog cov khoom sib xyaw ua ke thiab cov khoom noj tsis tau ua haujlwm. Ntau theem kev ntxuav - feem ntaukev rho tawm—yog siv rau kev sib cais, nrog rau kev tsom mus rau cov txheej txheem ntxuav vinyl chloride monomer. Kev ua haujlwm ntawm VCM distillation tower thiab cov txheej txheem sib xyaw ua ke cua sov tau ua kom zoo tshaj plaws kom ua kom huv si (feem ntau >99.9%), qhov tseem ceeb rau kev ua kom zoo ntawm PVC polymerization. Cov ntsuas qhov ceev hauv kab xws li cov uas tsim los ntawm Lonnmeter feem ntau siv los saib xyuas qhov ceev ntawm VCM kua ntawm ntau qhov kub thiab txias, pab cov neeg ua haujlwm pom sai sai cov pawg tsis raws li qhov xav tau lossis cov xwm txheej ua qias tuaj.
Cov chaw tsim khoom nyiam cov qauv sib xyaw ua ke uas muab cov tshuaj chlorine ncaj qha thiab cov tshuaj oxychlorination reactors, kev sib koom ua ke ntawm kev rov ua dua tshiab ntawm hydrogen chloride, thiab cov tswv yim rov qab siv hluav taws xob. Cov qauv sib xyaw no txhawb nqa cov nqi khoom noj khoom haus qis dua thiab kev siv hluav taws xob zoo dua. Cov txheej txheem thev naus laus zis vinyl chloride monomer tshiab siv zog rau kev tsim khoom siab, kev nyab xeeb, thiab kev ywj pheej hauv kev tswj hwm ntau yam khoom siv raw, thaum kev saib xyuas nruj ntawm cov khoom tseem ceeb (suav nrog qhov ceev thiab kev huv) ntawm ntau yam txheej txheem ua kom ntseeg tau tias PVC zoo thiab kev ua raws li txoj cai rau kev noj qab haus huv, kev nyab xeeb, thiab ib puag ncig.
Cov Txheej Txheem Nthuav Dav ntawm Vinyl Chloride Monomer Production
Daim duab qhia txog cov txheej txheem tsim khoom ntawm Vinyl Chloride
Kev tsim cov vinyl chloride monomer (VCM) niaj hnub no vam khom cov txheej txheem sib koom ua ke, feem ntau pom los ntawm daim duab qhia txog txhua kauj ruam tseem ceeb. Cov txheej txheem pib nrog cov khoom siv raw - feem ntau yog ethylene, chlorine, hydrogen chloride, thiab oxygen. Hauv kev tsim cov nroj tsuag vinyl chloride monomer, cov ntaub ntawv no raug xa mus rau hauv cov tshuab chlorination thiab oxychlorination los tsim cov ethylene dichloride (EDC), qhov nruab nrab nruab nrab.
Hauv kev siv chlorine ncaj qha, ethylene ua rau muaj kev cuam tshuam nrog chlorine nyob rau hauv qhov kub thiab txias (40–90°C) los tsim EDC. Nyob rau tib lub sijhawm, lub tshuab oxychlorination sib xyaw ua ke hydrogen chloride (feem ntau rov ua dua los ntawm cov kauj ruam tom qab), ethylene, thiab oxygen - siv cov catalyst uas ua los ntawm tooj liab ntawm qhov kub siab dua (200–250°C) los tsim EDC thiab dej. Ob txoj kev ua haujlwm tau sib koom ua ke los rov ua dua cov pa roj tsis tau ua haujlwm thiab ua kom zoo dua cov nqi siv, tsim lub hauv paus ntawm cov txheej txheem tsim cov vinyl chloride monomer sib npaug.
Kev ntxuav cov EDC nyoos suav nrog cov kab distillation uas tshem tawm cov dej, cov khoom siv hydrocarbon chlorinated, thiab lwm yam tsis huv. Cov EDC uas tau ua kom huv ces pub rau lub cub tawg pyrolysis, lossis tawg, - ib qho txheej txheem ua haujlwm ntawm 480–520 ° C thiab qhov siab nruab nrab. Ntawm no, thermal decomposition tsim VCM thiab tso tawm hydrogen chloride, uas feem ntau rov qab mus rau lub voj voog oxychlorination. Kev quenching thiab txias sai ntawm cov pa tawg tiv thaiv cov tshuaj tiv thaiv tsis xav tau thiab ua rau cov khoom tsim kev phom sij puas tsuaj.
Cov pa roj uas tshwm sim tau raug cais thiab ntxuav los ntawm kev siv cov kem distillation ntxiv thiab cov khoom sib cais theem. Cov txheej txheem ntxuav VCM tshwj xeeb, suav nrog kev distillation thiab kev nqus ntau theem, ua kom cov khoom huv si feem ntau tshaj 99.9%. Cov EDC uas tsis muaj zog rov ua dua tshiab tau rov ua dua tshiab, ua kom muaj kev hloov pauv ntau tshaj plaws thaum txo cov pa phem. Cov txheej txheem tswj hwm nruj thiab kev saib xyuas cov txheej txheem ntau zaus tiv thaiv kev xau thiab ua kom ua raws li cov txheej txheem kev nyab xeeb rau cov kua vinyl chloride uas yooj yim hlawv, ua rau mob qog noj ntshav.
Thoob plaws hauv cov txheej txheem tsim cov vinyl chloride monomer, kev tswj hwm lub zog thiab kev rov qab los ntawm cua sov yog qhov tseem ceeb rau kev ruaj khov. Cov cua sov exothermic los ntawm chlorination thiab oxychlorination raug rov qab los, ua ntej cua sov cov khoom noj yav tom ntej lossis tsim cov pa dej ua haujlwm. Kev tshuaj xyuas pinch thiab cov tswv yim sib xyaw ua ke cua sov raug siv thoob plaws cov tes hauj lwm sib pauv cua sov, txo qis kev siv roj thiab kev cuam tshuam rau ib puag ncig.
Cov platform simulation txheej txheem—feem ntau yog Aspen Plus—yog qhov tseem ceeb rau kev tsim qauv, kev nthuav dav, thiab kev ua kom zoo dua. Cov qauv digital no simulate cov khoom sib npaug, cov tshuaj tiv thaiv kinetics, tus cwj pwm theem, thiab cov zog ntws ntawm txhua kauj ruam, ua rau muaj kev lees paub sai ntawm kev ua haujlwm ntawm cov nroj tsuag hauv ntau qhov xwm txheej sib txawv. Kev siv hluav taws xob zoo, EDC-rau-VCM cov txiaj ntsig, thiab cov khoom thauj ib puag ncig raug kho tas li siv cov ntaub ntawv simulation, txhawb nqa ob qho tib si kev lag luam thiab kev cai lij choj rau cov txheej txheem thev naus laus zis vinyl chloride monomer siab heev.
Kev Ua Haujlwm Tseem Ceeb hauv Lub Hoobkas VCM
EDC Synthesis thiab Purification
EDC synthesis siv ob txoj kev sib txuas ua ke - chlorination ncaj qha thiab oxychlorination - txhua tus nrog cov kev xav tau ua haujlwm sib txawv. Hauv chlorination ncaj qha, kev sib xyaw ua ke ntawm ethylene thiab chlorine zoo tshwm sim hauv lub tshuab ua kua, nrog kev tswj qhov kub kom tsis txhob muaj cov khoom tsim ntau dhau. Sov exothermically, lub tshuab ua kua no xav tau kev txias sib xyaw ua ke thiab kev sib cais roj-theem kom tiv thaiv kev hloov pauv zoo.
Kev siv cov tshuaj oxychlorination siv lub tshuab reactor uas ruaj khov lossis lub tshuab fluidized, siv cov catalyst tooj liab chloride uas txhawb nqa ntawm alumina. Ethylene, cov hydrogen chloride rov ua dua tshiab, thiab cov pa oxygen tau sib xyaw thiab ua rau muaj kev cuam tshuam ntawm 200–250 ° C. Cov txheej txheem tsim tawm ob qho tib si EDC thiab cov pa dej. Kev tswj qhov kub thiab txias zoo thiab kev sib npaug stoichiometric txo cov khoom phom sij chlorinated.
Cov dej EDC nyoos uas sib xyaw ua ke los ntawm ob txoj kev no raug ntxuav kom huv si. Cov kauj ruam pib tshem tawm cov dej uas tsim thaum lub sijhawm oxychlorination los ntawm kev sib cais theem thiab kev distillation. Cov kem thib ob tshem tawm cov tshuaj sib xyaw ua ke (xws li chloroform) thiab cov kawg hnyav, ua rau EDC huv si uas tsim nyog rau kev ua haujlwm siab pyrolysis. Cov voj voog rov ua dua tshiab rov qab tau cov khoom siv tsis tau hloov pauv thiab cov khoom lag luam, ua kom zoo dua kev siv cov khoom siv raw hauv qhov kev teeb tsa kaw-loop no.
Kev tawg ntawm cov khoom siv thermal rau vinyl chloride
Kev tawg ntawm cov cua sov, lossis pyrolysis, yog qhov ua rau VCM tsis ua haujlwm. Ntawm no, cov pa roj EDC uas muaj qhov huv si siab raug cua sov rau 480–520 ° C hauv lub cub tawg tubular, feem ntau cua sov tsis ncaj qha kom tswj tau qhov kub thiab txias thiab zam cov chaw kub. Qhov kev ua haujlwm endothermic no ua rau EDC tawg los ua vinyl chloride monomer thiab hydrogen chloride los ntawm cov txheej txheem dawb-radical.
Cov txheej txheem tseem ceeb uas hloov pauv tau—kub, lub sijhawm nyob, thiab siab—tau raug kho kom zoo siv cov txheej txheem tswj cov txheej txheem siab heev thiab cov qauv simulation. Qhov kub ntau dhau tuaj yeem ua rau polymeric fouling thiab cov khoom tsim tawm xws li tar lossis cov tshuaj chlorine hnyav. Kev tua sai sai tom qab tawg yuav nres cov tshuaj tiv thaiv sab nraud thiab ua rau cov khoom siv tau yooj yim. Kev tshuaj xyuas cov txheej txheem taug qab HCl tiam, uas feem ntau rov qab tau thiab rov qab mus rau oxychlorination.
VCM Purification thiab Distillation
Kev ntxuav cov dej ntws mus rau hauv qab yog qhov tseem ceeb rau kev ua tiav qhov siab ntawm vinyl chloride monomer purity. Kev sib cais roj-kua tshem tawm cov dej thiab cov khoom seem hnyav dua ua ntej cov kab distillation tseem ceeb. Cov txheej txheem distillation vinyl chloride monomer ua haujlwm nyob rau hauv kev tswj hwm siab thiab kub, kom ntseeg tau tias kev sib cais ntawm cov EDC, HCl, thiab azeotropes tsis muaj tshuaj lom nrog lwm cov organic chlorinated.
Qhov sib piv ntawm lub zog ntawm lub kem thiab qhov sib piv ntawm cov cua sov rov qab los (reflux ratios) raug kho kom zoo kom siv hluav taws xob sib npaug rau lub hom phiaj ntawm kev huv - qhov rov qab los ntau dua yuav txhim kho kev sib cais ntawm tus nqi ntawm lub zog ntawm cov pa thiab lub zog txias. Cov txheej txheem condensation thiab reboiler ntau yam ua rau kev ua haujlwm zoo dua, tshwj xeeb tshaj yog thaum ua ke nrog kev rov qab los ntawm cua sov.
Tshaj li kev sib cais lub cev, cov tswv yim tswj cov txheej txheem siab heev ua rau muaj kev hloov kho lub sijhawm tiag tiag rau cov xwm txheej ntawm cov kem, teb rau qhov sib txawv ntawm cov khoom noj lossis cov xwm txheej tsis raws li qhov tau teev tseg. Kev ntsuam xyuas kev pheej hmoo ntawm ntau yam ua rau muaj kev nyab xeeb hauv kev ua haujlwm, txhawb kev tshawb pom qhov xau thiab kev txo qis qhov pa phem rau cov tshuaj lom neeg no. Kev siv cov kev daws teeb meem ntsuas online, xws li cov ntsuas qhov ceev thiab viscosity los ntawm Lonnmeter, muab kev soj ntsuam tseeb, lub sijhawm tiag tiag uas tseem ceeb rau qhov zoo ntawm cov khoom thiab kev ua haujlwm nyab xeeb.
Cov Khoom Siv Lub Cev thiab Tshuaj Lom Zem Uas Muaj Feem Xyuam rau Kev Tsim VCM
VCM Cov Kua Ceev thiab VCM Cov Kua Tswj
Qhov ceev ntawm cov kua VCM sib txawv ntau nrog rau qhov kub thiab txias - qhov tseem ceeb ntawm kev ua haujlwm hauv kev tuav thiab khaws cia vinyl chloride monomer. Ntawm cov xwm txheej ib txwm muaj (20 ° C), qhov ceev ntawm vinyl chloride monomer feem ntau yog 0.911–0.913 g / cm³. Thaum qhov kub nce siab, qhov ceev txo qis, cuam tshuam rau qhov ntim ntws thiab kev suav cov khoom khaws cia hauv lub tank.
Piv txwv li, ntawm 0°C, qhov ceev tuaj yeem nce mus txog kwv yees li 0.930 g/cm³, thaum ntawm 50°C nws poob ze rau 0.880 g/cm³. Cov kev hloov pauv no yuav tsum tau rov kho dua cov khoom siv hloov pauv thiab kev saib xyuas cov txheej txheem ceev faj, vim tias kev hloov pauv cuam tshuam rau cov kauj ruam txheej txheem polymerization PVC downstream. Lonnmeter's inline liquid density meters feem ntau raug xa mus rau hauv cov circuits no rau kev txheeb xyuas tas mus li, txhawb kev tswj cov khoom muag thiab kev hloov pauv kev saib xyuas los ntawm kev muab cov ntawv nyeem ze li ntawm tam sim ntawd thoob plaws cov txheej txheem hloov pauv.
Cov yam ntxwv ntawm kev yaj ntawm cov kua vinyl chloride kuj tseem ceeb heev. VCM tsuas yog yaj me ntsis hauv dej tab sis sib xyaw nrog cov organic solvents, uas cuam tshuam rau kev xaiv cov khoom siv kaw thiab kev ntsuas thaum muaj xwm txheej ceev thaum tuav thiab khaws cia.
Kev Nyab Xeeb thiab Kev Tswj Xyuas Ib puag ncig
Vinyl chloride yog cov kua thiab cov pa uas yoo yoo yoo yoo yoo yoo, nrog rau qhov kub hnyiab qis txog li -78°C thiab muaj ntau yam tawg. Nws cov tshuaj lom thiab cov kab mob carcinogenic uas paub tias yog qhov ua rau mob qog noj ntshav yuav tsum muaj kev nyab xeeb vinyl chloride monomer nruj heev. Hauv kev tsim cov txheej txheem, cov kav dej ob phab ntsa, cov pa nitrogen, thiab cov tes hauj lwm nrhiav kev xau dav dav tau siv thoob plaws hauv cov txheej txheem tsim khoom vinyl chloride monomer.
Kev thauj mus los thiab kev khaws cia siv cov nkoj uas muaj qhov ntsuas siab uas muaj cov tshuab pab txhawb thiab cov chaw txias kom txo qhov siab ntawm cov pa thiab yog li tso tawm kev pheej hmoo. Cov txheej txheem kev saib xyuas thiab kev tswj hwm cov pa phem tiag tiag pab txhawb kev nyab xeeb hauv chaw ua haujlwm thiab kev ua raws li ib puag ncig. Rau cov kwj dej uas muaj qhov cua, cov tshuab ntxuav thiab cov chaw hlawv roj txo cov pa roj chlorinated, ua raws li cov qauv kev cai lij choj hauv kev ua haujlwm tshuaj lom neeg hauv kev lag luam. Kev npaj thaum muaj xwm txheej ceev thiab kev cob qhia tsis tu ncua tseem yog cov kev coj ua yuav tsum tau ua hauv txhua lub Hoobkas VCM niaj hnub no, vim muaj peev xwm ua rau muaj kev phom sij rau kev raug mob hnyav thiab ntev ntev uas cuam tshuam nrog cov tshuaj no.
Kev Txhim Kho Cov Txheej Txheem thiab Kev Txhim Kho Kev Ua Haujlwm Zoo
Kev Txhim Kho Zog thiab Kev Sib Koom Ua Ke
Kev sib xyaw ua ke ntawm cua sov tau dhau los ua lub tswv yim tseem ceeb hauv kev tsim cov txheej txheem tsim cov vinyl chloride monomer. Kev tshuaj xyuas pinch yog txoj hauv kev tseem ceeb rau kev kos duab cov dej kub thiab txias, qhia txog qhov chaw pinch - qhov kub thiab txias uas qhov rov qab los ntawm cua sov tau siab tshaj plaws. Hauv cov nroj tsuag vinyl chloride monomer ib txwm muaj, cov dej loj uas xav tau kev txias, xws li EDC pyrolysis effluent, raug phim nrog cov dej uas xav tau kev cua sov, xws li reboilers hauv VCM purification steps. Cov kab sib xyaw ua ke pab txiav txim siab qhov tsawg kawg nkaus kub thiab txias xav tau kev pabcuam, kom ntseeg tau tias cov txheej txheem ua haujlwm ze rau nws cov kev txwv thermodynamic efficiency.
Cov tes hauj lwm sib pauv cua sov zoo tshaj plaws (HENs) rov qab tau cua sov los ntawm cov kwj dej kub tawm mus kom ua kom cov khoom noj txias tuaj. Kev siv zog rov qab no txo cov nqi zog thiab cov nqi siv cua txias los ntawm 10-30% thaum siv nruj, raws li pom hauv kev tshawb fawb ntawm cov nroj tsuag VCM puv ntoob. Cov ntawv thov kho dua tshiab yog qhov tshwm sim, pab txhawb cov khoom siv uas twb muaj lawm los ntawm kev ntxiv cov khoom sib pauv sib luag lossis rov kho dua qhov ntws yam tsis muaj sijhawm tsis ua haujlwm ntau. Qhov kev siv theem no, tau txheeb xyuas los ntawm kev sim ua kom ruaj khov, ua kom ntseeg tau tias kev txuag hluav taws xob yog qhov tseeb thaum tseem khaws cov nqi peev nruab nrab.
Kev koom ua ke raws li kev txwv tsis pub ua ntau tshaj li kev txiav cov nqi khiav lag luam. Nws kuj tseem hloov pauv tag nrho kev ua tau zoo ib puag ncig - roj tsawg dua hlawv txhais tau tias cov pa phem CO₂ tsawg dua, txhawb nqa kev ua raws li cov cai tswjfwm kev tso pa phem. Cov kev txuag pa phem feem ntau yog sib npaug rau lub zog txuag; cov nroj tsuag tshaj tawm txog li 25% kev txo qis hauv CO₂ los ntawm ntu VCM ib leeg tom qab HEN retrofit lees paub los ntawm kev tshuaj xyuas cov kab sib xyaw.
Cov Txheej Txheem Txhim Kho Cov Txheej Txheem Siab Tshaj Plaws
Cov txheej txheem simulations txhawb nqa kev ua kom zoo dua ntawm cov txheej txheem tsim khoom vinyl chloride monomer. Siv cov qauv simulation ruaj khov, cov engineers tsim thiab ntsuas cov chav tshiab, sim ntau qhov xwm txheej ua haujlwm, thiab xyuas kom meej tias lub zog thiab cov khoom siv sib npaug zoo. Qhov no ua kom muaj kev ua tau zoo thoob plaws cov txheej txheem sib txawv thiab cov nqi tsim khoom xav tau.
Kev ua kom zoo dua ntau lub hom phiaj, siv cov txheej txheem xws li cov txheej txheem genetic algorithms, sib npaug cov kev sib tw tseem ceeb. Hauv kev ua haujlwm VCM, lub hom phiaj tseem ceeb yog cov khoom tsim tawm, kev siv hluav taws xob tsawg kawg nkaus, thiab txo cov pa roj av uas ua rau lub tsev cog khoom puas tsuaj. Cov txheej txheem niaj hnub no sib xyaw cov kev suav lej nrog kev paub txog cov txheej txheem heuristic los tsim cov qauv cog qoob loo uas muaj tseeb thiab ua haujlwm tau yooj yim. Cov txheej txheem no feem ntau xa cov kev daws teeb meem nrog kev rov qab ua kom sov zoo dua thaum tswj cov khoom siv thiab cov qauv kev huv ntawm cov khoom tseem ceeb rau cov kauj ruam PVC polymerization.
Kev hloov kho dua tshiab yog qhov tseem ceeb. Tom qab xaiv thawj qhov kev teeb tsa HEN los ntawm kev simulation, cov ntaub ntawv cog qoob loo thiab kev saib xyuas digital muab kev ntsuam xyuas kev ua haujlwm tiag tiag. Cov neeg ua haujlwm tuaj yeem ua qhov kev hloov kho me me - xws li kev hloov kho cov txheej txheem ntws lossis kev faib cov dej num hloov pauv cua sov - raws li qhov kub thiab txias tiag tiag. Lub voj voog tawm tswv yim no ua kom muaj kev ua haujlwm sib xws ze ntawm cov ntsiab lus tsim qauv zoo tshaj plaws txawm tias cov khoom noj khoom haus lossis kev thov ntau lawm hloov pauv.
Cov cuab yeej xws li cov ntsuas qhov ceev hauv kab thiab cov ntsuas viscosity los ntawm Lonnmeter muab kev ntsuas ncaj qha ntawm cov khoom kua hauv lub sijhawm tiag tiag. Cov kev ntsuas no txheeb xyuas qhov sib txawv uas yuav tshwm sim los ntawm kev ua qias tuaj, kev cuam tshuam ntawm cov txheej txheem, lossis cov khoom pub mis tsis raws li qhov tau teev tseg. Nrog cov ntaub ntawv qhov ceev thiab viscosity raug, lub sijhawm tiag tiag, cov neeg teb xov tooj tswj hwm cov hom phiaj kev ua tau zoo uas tau teeb tsa thaum lub sijhawm tsim thiab kev ua haujlwm.
Kev Ntsuam Xyuas Kev Lag Luam thiab Kev Ntsuas Kev Ruaj Ntseg
Ib qho kev ntsuam xyuas kev lag luam dav dav rau lub Hoobkas VCM suav nrog kev nqis peev, cov nuj nqis khiav lag luam, thiab lub sijhawm rau kev them rov qab. Kev siv nyiaj peev pib suav nrog tus nqi ntawm cov khoom pauv tshiab, cov kav dej, thiab cov txheej txheem rov ua dua tshiab uas xav tau los siv lossis kho dua lub network pauv cua sov. Rau kev kho dua tshiab, cov nqi peev ntxiv tseem me me vim tias cov khoom siv tseem ceeb tau rov siv dua lossis rov siv dua. Cov nyiaj txuag ua haujlwm - feem ntau yog lub zog - feem ntau them taus kev nqis peev hauv 1-3 xyoos, tshwj xeeb tshaj yog nyob rau hauv cov cheeb tsam uas muaj roj av lossis cov nqi pa siab.
Cov kev ntsuas kev ruaj khov hauv cov txheej txheem tsim cov vinyl chloride monomer suav nrog ntau dua li kev siv hluav taws xob. Cov kev ntsuas tseem ceeb suav nrog kev siv cov peev txheej tag nrho, CO₂ emissions ib tuj ntawm cov khoom, thiab kev siv dej hauv cov cua txias. Kev tshuaj xyuas ntawm cov kev tshawb fawb tsis ntev los no lees paub tias kev ua tiav HEN optimization tas li tsav tsheb kev txhim kho hauv cov ntsuas no. Tag nrho cov peev txheej nkag mus rau hauv ib tuj ntawm VCM poob qis, emissions poob qis, thiab kev ua raws li cov qauv kev tshaj tawm kev ruaj khov zoo dua.
Cov xwm txheej them rov qab feem ntau suav nrog kev txuag nyiaj ncaj qha thiab cov txiaj ntsig tsis ncaj qha xws li cov se carbon tsawg dua thiab cov nqi tso cai tso pa tawm tsawg dua. Hauv cov cheeb tsam uas muaj kev nyuaj siab ntawm kev cai lij choj, lub peev xwm ntawm lub Hoobkas vinyl chloride monomer los qhia txog kev txhim kho tas mus li ntawm cov ntsuas no muaj feem cuam tshuam rau kev ua neej nyob ntev thiab kev sib tw.
Hauv kev xaus lus, kev ua kom zoo dua ntawm cov txheej txheem thiab kev sib koom ua ke ntawm lub zog—uas tau txhawb nqa los ntawm kev sim ua ntej, kev ua kom zoo dua ntau lub hom phiaj, thiab kev ntsuas ncaj qha (xws li cov uas tau ua los ntawm Lonnmeter thev naus laus zis)—yog lub hauv paus ntawm kev tsim cov nroj tsuag vinyl chloride monomer niaj hnub, ua haujlwm tau zoo, thiab ruaj khov.
Polyvinyl Chloride (PVC) Polymerization Siv VCM
Kev Taw Qhia Txog PVC Polymerization Txheej Txheem
Vinyl chloride monomer (VCM) yog lub hauv paus tseem ceeb rau kev tsim cov polyvinyl chloride (PVC). Cov tshuaj vinyl chloride polymerization ua rau cov kua dej tsis muaj xim thiab tsis muaj zog no hloov mus ua ib qho ntawm cov yas siv ntau tshaj plaws hauv ntiaj teb. PVC polymerization feem ntau yog ua los ntawm kev siv cov txheej txheem suspension thiab emulsion.
Nyob rau hauv lubcov txheej txheem polymerization ntawm kev ncua, VCM raug faib rau hauv dej nrog kev pab los ntawm cov neeg sawv cev xws li polyvinyl cawv lossis methyl cellulose. Cov txheej txheem pib nrog kev sib xyaw siab-shear kom tsim cov dej me me VCM uas raug ncua hauv theem aqueous. Cov neeg pib polymerization, feem ntau yog cov organic peroxides lossis azo compounds, tom qab ntawd raug qhia. Hauv qab qhov kub thiab txias uas tswj tau zoo (feem ntau 40–70 ° C), cov dej VCM polymerize, tsim cov hlaws lossis cov khoom me me ntawm PVC. Cov khoom raug tuav hauv qab kev sib xyaw, thiab tus nqi tshuaj tiv thaiv yog dictated los ntawm hom pib, concentration, thiab qhov kub thiab txias. Kev kho kom zoo ntawm cov kev ntsuas no yog qhov tseem ceeb kom ntseeg tau tias muaj qhov faib me me thiab sib npaug. Thaum ua tiav, cov tshuaj tiv thaiv sib xyaw raug txias, VCM tsis tau ua haujlwm raug stripped, thiab cov neeg sawv cev ruaj khov lossis cov neeg hloov kho yuav raug qhia ua ntej cov txheej txheem lim dej, ntxuav, thiab ziab tom qab.
LubTxoj kev polymerization ntawm emulsionua haujlwm nrog cov kev cai sib txawv. Ntawm no, VCM yog emulsified hauv dej siv surfactants (xab npum zoo li cov molecules), tsim cov droplet me dua piv rau cov txheej txheem ncua. Txoj kev no tsim cov PVC latex - ib qho colloidal dispersion zoo tagnrho rau cov ntawv thov tshwj xeeb, xws li coatings lossis synthetic leathers. Initiator systems feem ntau vam khom redox pairs, ua haujlwm ntawm qhov kub qis dua. Emulsion polymerization tso cai rau kev tswj hwm zoo dua ntawm cov yam ntxwv ntawm cov khoom me me, xws li morphology thiab porosity, txawm hais tias nws cuam tshuam nrog cov kauj ruam rov qab khoom ntau dua.
Cov thev naus laus zis niaj hnub PVC polymerization feem ntau koom ua ke cov cuab yeej saib xyuas qhov chaw, xws li cov khoom ntsuas qhov loj me ntawm cov khoom me me lossis cov ntsuas qhov ceev hauv kab (raws li tsim los ntawm Lonnmeter), rau hauv cov txheej txheem. Cov cuab yeej no muab cov lus teb rov qab tiag tiag, tso cai rau kev hloov kho tas mus li rau qhov ceev ntawm kev sib xyaw, qhov kub, thiab kev pub mis pib, yog li ua kom cov khoom sib xws thiab txo cov khib nyiab.
Cov Kev Ntsuas Zoo ntawm VCM rau Kev Tsim Khoom PVC Zoo
Qhov ua tau zoo thiab zoo ntawm kev tsim khoom PVC yog txuas nrog rau cov khoom siv lub cev thiab tshuaj ntawm VCM. VCM uas muaj kev ntshiab siab yog qhov tseem ceeb rau kev ua kom polymerization zoo thiab kev ua tau zoo ntawm polymer.
Cov khoom tsis huv uas muaj nyob hauv VCM—xws li cov dej seem, acetylene, cov organic chlorinated, lossis cov hlau ions—tuaj yeem ua rau cov tshuaj lom, qeeb qeeb cov nqi polymerization, thiab ua rau muaj qhov tsis zoo rau hauv PVC resin. Piv txwv li, qhov muaj cov hydrocarbons chlorinated me me, txawm tias nyob rau hauv qhov ntau ntawm ib lab, tuaj yeem hloov pauv qhov kinetics ntawm cov tshuaj tiv thaiv lossis ua rau cov khoom tsis muaj xim. Cov txheej txheem ntxuav vinyl chloride monomer zoo tau siv rau sab saud, siv cov txheej txheem xws li ntau theem distillation (ua haujlwm hauv VCM distillation towers) los txo cov khoom tsis huv mus rau qhov txwv tsis pub dhau.
Cov khoom siv lub cev—tshwj xeeb yog qhov ceev ntawm VCM thiab nws txoj kev tswj—ua lub luag haujlwm ncaj qha rau kev tuav thiab kev ua dua tshiab ntawm cov txheej txheem. VCM qhov ceev ntawm cov kua sib txawv ntau nrog rau qhov kub thiab txias, cuam tshuam rau qhov tseeb ntawm kev ntsuas, tus cwj pwm theem thaum lub sijhawm polymerization, thiab kev ua haujlwm ntawm kev sib xyaw. Piv txwv li, ntawm 0 ° C, VCM qhov ceev yog kwv yees li 1.140 g / cm³, poob qis nrog rau qhov kub thiab txias nce. Kev saib xyuas qhov ceev ntawm VCM kua tiag tiag (siv cov ntsuas qhov ceev hauv kab zoo li cov los ntawm Lonnmeter) ua kom muaj qhov sib piv pub mis raug, ua rau muaj kev suav qhov hloov pauv cua sov raug, thiab txhawb nqa kev sib npaug ntawm cov khoom lag luam.
Cov khoom seem uas tsis muaj kuab lom, tshwj xeeb yog cov VCM uas tsis tau teb, tuaj yeem ua rau muaj kev nyab xeeb thiab qhov zoo ntawm cov khoom puas tsuaj. Cov VCM dawb ntau ntxiv hauv cov PVC tiav lawm muaj kev pheej hmoo ntawm kev lom thiab tuaj yeem cuam tshuam tsis zoo rau cov khoom xws li porosity, lub zog kho tshuab, thiab xim ruaj khov. Cov cai feem ntau yuam kom muaj cov kauj ruam tshem tawm tag nrho thiab kev saib xyuas VCM tas mus li thoob plaws hauv lub voj voog ntau lawm kom ntseeg tau tias cov khoom tsim tawm muaj kev nyab xeeb thiab ua raws li txoj cai.
Qhov cuam tshuam ntawm VCM zoo rau PVC yog qhov zoo tshaj plaws hauv daim ntawv qhia hauv qab no:
| Tus cwj pwm zoo ntawm VCM | Cov nyhuv rau PVC Txheej Txheem thiab Khoom |
| Kev huv (kev sib xyaw ua ke ntawm tshuaj lom neeg) | Ncaj qha cuam tshuam rau tus nqi polymerization, kev faib tawm ntawm qhov hnyav molecular, xim, thiab thermal stability |
| Lub cev nqaij daim tawv (qhov ceev ntawm kua) | Cuam tshuam rau qhov tseeb ntawm kev ntsuas, kev sib tov zoo, thiab cov qauv polymer |
| Cov ntsiab lus tsis huv | Ua rau tus pib ua haujlwm tsis zoo, kev tiv thaiv kev ua haujlwm, thiab cov khoom siv tsis zoo / siv kawg |
| Cov seem (piv txwv li, dej, cov organic) | Tej zaum yuav ua rau muaj qhov tsis zoo ntawm cov porosity, cov qauv tsis sib xws, thiab cov teeb meem ua tiav hauv qab |
Kev ua kom muaj kev tswj hwm zoo ntawm VCM los ntawm kev ua kom huv siab heev, kev khaws cia kom zoo, thiab cov thev naus laus zis ntsuas qhov ceev tiag tiag yog qhov tseem ceeb rau kev tsim cov nroj tsuag vinyl chloride monomer zoo thiab rau kev ua kom tau raws li cov kev ntsuas kev nyab xeeb uas xav tau hauv cov txheej txheem thev naus laus zis niaj hnub vinyl chloride monomer.
Cov Lus Nug Feem Ntau
Cov txheej txheem vinyl chloride monomer yog dab tsi?
Cov txheej txheem tsim cov vinyl chloride monomer yog ib qho kev lag luam uas hloov ethylene mus rau hauv vinyl chloride monomer (VCM), uas yog cov khoom noj tseem ceeb rau kev tsim cov PVC resin. Nws pib nrog chlorination ntawm ethylene, tsim ethylene dichloride (EDC), feem ntau los ntawm kev chlorination ncaj qha lossis oxychlorination. Tom ntej no, EDC uas muaj kev ntshiab siab raug tawg hauv cov cub tawg ntawm 480–520 ° C, ua rau VCM thiab hydrogen chloride (HCl). Hauv qab no, ntau lub tsev distillation purify VCM, tshem tawm cov khoom tsis huv thiab dej kom xa >99.9% kev ntshiab tseem ceeb rau polymerization. Qhov nyuaj thiab kev teeb tsa ntawm daim duab ntws ntawm vinyl chloride monomer nyob ntawm kev tsim cov nroj tsuag, cov hom phiaj ua haujlwm tau zoo, thiab kev koom ua ke ntawm cov khib nyiab.
Lub Hoobkas vinyl chloride monomer ua li cas thiaj ua kom muaj kev nyab xeeb thiab ua raws li kev cai ib puag ncig?
Vim tias VCM yog cov khoom siv hluav taws xob uas yooj yim hlawv, ua rau mob qog nqaij hlav, thiab muaj kev phom sij rau ib puag ncig, kev tsim cov nroj tsuag vinyl chloride monomer muab qhov tseem ceeb rau kev tswj thiab kev txo qis. Cov chaw siv cov kev daws teeb meem tswj kev tso pa tawm ntau txheej los ntes cov pa organochlorine. Cov txheej txheem nrhiav kev xau tsis siv neeg thiab cov txheej txheem kaw cov txheej txheem tiv thaiv kev tso tawm tsis raug. Cov chaw tseem ceeb siv cov foob roj thiab cov chav ua haujlwm tshwj xeeb. Cov khoom siv HCl raug rov ua dua lossis kho kom txo qis cov dej khib nyiab. Kev tua hluav taws tom qab EDC tawg tiv thaiv kev tsim cov dioxin. Kev ua raws li kev cai lij choj tau ua tiav los ntawm kev saib xyuas lub sijhawm tiag tiag thiab kev ua raws li cov kev cai tswjfwm ntawm cov pa phem hauv huab cua thiab dej.
Cov kua vinyl chloride yog dab tsi, thiab vim li cas nws qhov ceev thiaj tseem ceeb?
Cov kua vinyl chloride yog cov kua VCM uas tau muab nias thiab muab nias rau hauv lub raj xa dej—khaws cia thiab thauj mus rau qhov kub qis lossis siab kom tiv thaiv kev ua pa. Qhov ceev ntawm cov kua vinyl chloride, feem ntau yog txij li 0.910 txog 0.970 g/cm³ nyob ntawm qhov kub thiab siab, yog qhov tseem ceeb rau kev tsim cov nkoj cia khoom, cov nkoj thauj khoom ntawm txoj kev, thiab cov kab hloov pauv. Cov ntaub ntawv ceev ntawm cov kua VCM kuj tseem ceeb rau kev taug qab cov khoom muag, kev sib xyaw ua ke, kev sib npaug ntawm cov khoom loj, thiab kev txheeb xyuas cov txiaj ntsig ntawm cov txheej txheem thoob plaws hauv kev tsim khoom. Cov ntsuas ceev hauv kab, xws li cov uas Lonnmeter tsim, muab kev saib xyuas tas mus li rau kev nyab xeeb thiab kev ua haujlwm zoo.
Vim li cas lub pej thuam distillation thiaj tseem ceeb hauv cov txheej txheem ntxuav VCM?
Cov chaw lim dej yog qhov tseem ceeb rau cov txheej txheem ntxuav vinyl chloride monomer. Lawv cais VCM ntawm cov seem EDC, cov khoom tsis huv uas kub tsawg, thiab "cov kawg hnyav" uas tsim thaum lub sijhawm tsim khoom. Kev ua haujlwm ntawm lub chaw lim dej VCM kom zoo ua kom ntseeg tau tias cov monomer polymerization-feed ua tau raws li cov qauv zoo. Txhua yam kev ua qias tuaj, xws li cov tshuaj tsis huv lossis dej noo, tuaj yeem cuam tshuam cov kauj ruam txheej txheem polymerization PVC, ua rau cov resin tsis raws li qhov xav tau, lossis ua rau cov catalysts downstream puas tsuaj. Cov txheej txheem ntxuav VCM siab heev siv cov rectifiers ntau yam thiab cov tais tshwj xeeb los ua kom zoo dua kev sib cais, rov qab cov khoom seem, thiab txo qis reboiler fouling.
Cov txheej txheem polymerization PVC cuam tshuam li cas rau kev tsim cov vinyl chloride monomer?
Qhov huv thiab ruaj khov ntawm VCM yog qhov yuav tsum tau ua ua ntej rau cov polyvinyl chloride resins zoo. Cov txheej txheem polymerization PVC siv VCM ncaj qha hauv cov reactors polymerization (feem ntau yog siv cov tshuaj ncua, emulsion, lossis bulk technology). Kev tswj hwm qhov tseeb ntawm cov khoom sib xyaw VCM cuam tshuam rau cov qauv molecular, cov qauv tsis huv, thiab cov khoom siv lub cev ntawm cov khoom PVC kawg. Qhov sib txuas ze ntawm cov txheej txheem tsim khoom vinyl chloride monomer thiab cov txheej txheem polymerization PVC txhais tau tias txhua qhov kev hloov pauv ntawm cov txheej txheem hauv VCM - xws li kev hloov pauv ntawm qhov ceev, cov khoom tsis huv, lossis kev hloov pauv kub - tuaj yeem nthuav mus rau theem polymerization, cuam tshuam rau kev ua haujlwm zoo thiab kev ua haujlwm ntawm cov khoom.
Lub sijhawm tshaj tawm: Lub Kaum Ob Hlis-18-2025
