Ukuqonda iNkqubo yeMonomer yeVinyl Chloride
I-vinyl chloride monomer (VCM) imi njengesiseko seshishini leplastiki lanamhlanje, ibonelela ngeyona nto ibalulekileyo yokwakha i-polyvinyl chloride (PVC). Njengekhemikhali yempahla, i-VCM isetyenziselwa kuphela i-PVC polymerization, evumela ukwenziwa kwayo yonke into ukusuka kwizixhobo zonyango kunye nezixhobo zokwakha ukuya kwiingubo zentambo kunye neempahla zabathengi. Imfuno ye-VCM ihambelana ngokusondeleyo nemveliso ye-PVC yehlabathi, okwenza imveliso yayo ekhuselekileyo, esebenzayo, nekhuselekileyo ibe yeyona nto ibalulekileyo kwimizi-mveliso.
I-VCM yigesi engenambala, etsha kakhulu kwiimeko ezingqongileyo, edla ngokuphathwa njengolwelo oluxinzelelweyo kwiindawo ezinikezelweyo. Ulwakhiwo lwayo lweekhemikhali, i-CH₂=CHCl, luquka iqela le-vinyl elidityaniswe ne-athomu enye ye-chlorine. Olu lungiselelo lwe-molecular luvumela i-polymerization elula, uphawu lwe-reactivity oluxhasa impendulo ye-vinyl chloride polymerization ebalulekileyo kumanyathelo enkqubo ye-PVC polymerization. Iimpawu zomzimba ze-vinyl chloride yolwelo—njengeqondo lokubila le-−13.4°C kunye noxinano lwe-0.91 g/mL kwi-20°C—zifuna ulawulo lwenkqubo oluqinileyo kunye neenkqubo zokugcina ezikhethekileyo ezigcina i-compound njengolwelo kwimisebenzi yenkqubo yokuvelisa i-vinyl chloride monomer esezantsi.
Inkqubo yeMonomer yeVinyl Chloride
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Ukusetyenziswa kwe-VCM ngaphandle kwe-PVC akunamsebenzi, nto leyo egxininisa indima yayo njenge-monomer ezinikeleyo yokwenza i-polymerization. Ngenxa yoko, zonke iinkalo zoyilo lwesityalo se-vinyl chloride monomer, ukusuka kuyilo lwesitimela se-reactor ukuya kwimveliso.ukucocakunye nokubuyiselwa, zilungiselelwe ukuguqulwa okukhulu, okuqhubekayo ukuze zibonelele ngetekhnoloji ye-PVC polymerization.
Nangona kunjalo, ukuphathwa nokugcinwa kwe-VCM kuyingozi enkulu. I-VCM ihlelwa njenge-Category 1 carcinogen, kunye nobungqina obuqinileyo obuyidibanisa ne-hepatic angiosarcoma kunye nezinye iziphumo zempilo ezibi emva kokuvezwa ixesha elide. Iprofayili yayo yetyhefu iyandiswa kukwenziwa kwee-metabolites ezisebenzayo, ezibopha ii-macromolecules zeseli kwaye ziphazamise iinkqubo zebhayoloji. Ukuvezwa ngokukhawuleza kukhokelela kuxinzelelo lwemithambo-luvo, ngelixa ukuvezwa okungapheliyo emsebenzini kunxulunyaniswa "nesifo sabasebenzi be-vinyl chloride" - isifo esiquka umonakalo wesibindi, iimpawu ezifana ne-scleroderma, kunye nezilonda zamathambo. Imida yokuvezwa elawulwayo ingqongqo: ukusukela ngo-2024, i-Occupational Safety and Health Administration (OSHA) imisela umda wokuvezwa ovumelekileyo weeyure ezi-8 we-1 ppm, kunye nemida ephantsi nangakumbi ecetyiswa yi-ACGIH kunye ne-NIOSH ukubonisa ukuqonda okuguquguqukayo kwetyhefu.
I-VCM ikwanokutsha kakhulu, inoluhlu oluqhumayo oluphakathi kwe-3.6% kunye ne-33% emoyeni. Ukudibana kwetyhefu kunye nokutsha kukhokelele kumanyathelo angqongqo okhuseleko kuzo zonke iziko lemveliso ye-VCM. Imigca yenkqubo ivalwe ngokupheleleyo kwaye igcinwa phantsi kweemeko ezingasebenziyo—ngesiqhelo i-nitrogen—kunye nokuchongwa kokuvuza okuqhubekayo kunye neenkqubo zomoya ongxamisekileyo. Umoya wokukhupha umoya kwindawo, ukuvalwa kwenkqubo, ukuthintelwa komlilo ovulekileyo, kunye neendawo zokufikelela ezilawulwa ngokuqinileyo kunciphisa umngcipheko. I-VCM engamanzi igcinwa kwaye ithuthwa phantsi koxinzelelo kwiitanki ezingamelani nokugqwala, idla ngokuzinziswa ngezithinteli ze-polymerization ezifana ne-phenol ukukhusela kwiimpendulo eziyingozi ezizenzekelayo.
Iindlela eziphambili zeMveliso yeVCM
Ukuveliswa kwe-VCM kulawulwa ziindlela ezimbini ezisetyenziswa kakhulu kwimizi-mveliso: i-chlorination ethe ngqo kunye ne-oxychlorination. Zombini zijikeleza ekudalweni nasekuguqulweni kwe-ethylene dichloride (EDC), eyona nto iphambili eqhekezwayo ukuze ivelise i-VCM.
Kwindlela yokukhlorina ngqo, i-ethylene isabela negesi yekhlorini kwinkqubo yesigaba solwelo esishushu kakhulu, ngokubanzi phezu kwekloridi ye-ferric okanye i-catalyst efanayo ukuvelisa i-EDC nge:
C₂H₄ + Cl₂ → C₂H₄Cl₂
Okanye, inkqubo ye-oxychlorination idibanisa i-ethylene, i-hydrogen chloride, kunye ne-oxygen isebenzisa i-copper(II) chloride catalyst, ivelisa i-EDC kunye namanzi:
C₂H₄ + 2HCl + ½O₂ → C₂H₄Cl₂ + H₂O
Le ndlela inika iingenelo zokuguquguquka kwezoqoqosho kunye nokutya ngokurisayikilisha i-HCl eveliswa ngexesha lokuveliswa kwe-VCM, ebekuya kubangela iingxaki zokulahla inkunkuma.
Nje ukuba i-EDC yenziwe, ifakwa kwi-thermal crack malunga ne-500°C, ngesiqhelo kwisigaba somphunga phezu kwepumice okanye ukupakisha nge-ceramic, ukuvelisa i-VCM kunye ne-hydrogen chloride:
C₂H₄Cl₂ → CH₂=CHCl (VCM) + HCl
Imveliso ye-VCM ephuma kwisithando esiqhekekayo ixutywe nomxube ontsonkothileyo weemveliso ezishiyekileyo kunye nezitokhwe zokutya ezingaphendulwanga. Amanqanaba amaninzi okucoca—ngokuyintlokoukuhluzwa—zisetyenziselwa ukwahlulahlula, kugxininiswa kakhulu kwinkqubo yokucoca i-vinyl chloride monomer. Ukusebenza kwe-VCM distillation tower kunye neenkqubo zokudibanisa ubushushu ezinxulumene nazo zilungiselelwe ukwandisa ubunyulu (ngesiqhelo >99.9%), ezibalulekileyo kwi-PVC polymerization esemgangathweni ophezulu. Iimitha zoxinano oluphakathi ezifana nezo zenziwe yiLonnmeter zihlala zisetyenziswa ukujonga uxinano lolwelo lweVCM kumaqondo obushushu ahlukeneyo, zinceda abaqhubi ukuba babone ngokukhawuleza iibhetshi ezingaqhelekanga okanye iziganeko zongcoliseko.
Izityalo zemveliso zikhetha uyilo oludibeneyo oludibanisa ii-reactors ze-chlorination ngqo kunye ne-oxychlorination, ukuphinda kusetyenziswe i-hydrogen chloride, kunye namaqhinga okubuyisela amandla. Ezi zakhiwo ze-hybrid zixhasa iindleko eziphantsi ze-feedstock kunye nokusetyenziswa kwamandla okuphuculweyo. Itekhnoloji yenkqubo ye-vinyl chloride monomer yanamhlanje ilwela ukuvelisa okuphezulu, ukhuseleko, kunye nokuguquguquka ekuphatheni iimpawu ezahlukeneyo zezinto ezikrwada, ngelixa ukujonga ngokungqongqo iipropati eziphambili (kubandakanya ubuninzi kunye nobunyulu) kwiindawo ezahlukeneyo zenkqubo kuqinisekisa ukuthotyelwa komgangatho we-PVC kunye nomthetho kwimpilo, ukhuseleko, kunye nokusingqongileyo.
Ukuhamba kweNkqubo eneenkcukacha zeMveliso yeVinyl Chloride Monomer
Umzobo wokuhamba kwenkqubo yokuvelisa i-vinyl chloride
Imveliso yanamhlanje ye-vinyl chloride monomer (VCM) ixhomekeke kwinkqubo edibeneyo, edla ngokubonwa ngumzobo opheleleyo odwelisa inyathelo ngalinye elibalulekileyo. Inkqubo iqala ngokufakwa kwezinto eziluhlaza—ngokuyintloko i-ethylene, i-chlorine, i-hydrogen chloride, kunye ne-oxygen. Ngaphakathi kuyilo lwesityalo se-vinyl chloride monomer, ezi zinto zihanjiswa nge-reactors ze-chlorination ngqo kunye ne-oxychlorination ukuze kuhlanganiswe i-ethylene dichloride (EDC), i-intermediate ephakathi.
Kwi-chlorination ethe ngqo, i-ethylene iphendula ne-chlorine phantsi kobushushu obulawulwayo (40–90°C) ukuvelisa i-EDC. Ngokufanayo, iyunithi ye-oxychlorination idibanisa i-hydrogen chloride (edla ngokuphinda isetyenziswe ukusuka kumanyathelo enkqubo kamva), i-ethylene, kunye ne-oxygen—isebenzisa i-catalyst esekelwe kubhedu kubushushu obuphezulu (200–250°C) ukuvelisa i-EDC namanzi. Zombini iindlela zokusabela zilungelelaniswe ukuze kusetyenziswe kwakhona iigesi ezingaphendulwanga kunye nokuphucula amazinga okusetyenziswa, okwenza isiseko senkqubo yokuvelisa i-vinyl chloride monomer elinganiselayo.
Ukucocwa kwe-EDC eluhlaza kubandakanya iintsika zokunyibilikisa ezisusa amanzi, iimveliso ze-hydrocarbon ezifakwe i-chlorine, kunye nezinye izinto ezingcolileyo. I-EDC ecociweyo emva koko yondla i-pyrolysis, okanye i-cracking furnace—inkqubo esebenza kwi-480–520°C kunye noxinzelelo oluphakathi. Apha, ukubola kobushushu kuvelisa i-VCM kwaye ikhuphe i-hydrogen chloride, ehlala ibuyiselwa kwi-oxychlorination loop. Ukucima kunye nokupholisa ngokukhawuleza kweegesi eziqhekekileyo kuthintela iimpendulo ezingafunekiyo kwaye kunciphisa ukwakheka kwemveliso enobungozi.
Umjelo wegesi ophumayo uyahlulwa kwaye ucocwe kusetyenziswa ezinye iikholamu zokunyibilikisa kunye nezahluli zesigaba. Iindlela ezinikezelweyo zokucoca i-VCM, kubandakanya ukunyibilikisa kunye nokufunxwa kwamanqanaba amaninzi, ziqinisekisa ubunyulu bemveliso obuqhele ukugqitha i-99.9%. I-EDC engaphendulwanga kakuhle iyaphinda isetyenziswe, iphucula kakhulu uguquko ngelixa inciphisa ukukhutshwa. Iinkqubo zokuthintela eziqinileyo kunye nokubeka esweni rhoqo inkqubo zikhusela ekuvuthweni kwaye ziqinisekisa ukuthotyelwa kwemigaqo yokhuseleko ye-vinyl chloride yolwelo olunokutsha, olubangela umhlaza.
Kuyo yonke inkqubo yokwenziwa kwe-vinyl chloride monomer, ulawulo lwamandla kunye nokubuyiselwa kobushushu kubalulekile ukuze kubekho uzinzo. Ubushushu obuvela kwi-chlorination kunye ne-oxychlorination buyaphinda buthathwe, kufudunyezwe izitokhwe zexesha elizayo okanye kuvelise umphunga wenkqubo. Uhlalutyo lwe-pinch kunye namaqhinga okudibanisa ubushushu asetyenziswa kwiinethiwekhi zokutshintsha ubushushu, ukunciphisa ukusetyenziswa kwepetroli kunye nempembelelo kwindalo esingqongileyo.
Amaqonga okulinganisa iinkqubo—ikakhulukazi i-Aspen Plus—abalulekile kuyilo, ukukhulisa, kunye nokwenza ngcono. Ezi modeli zedijithali zilingisa ibhalansi yezinto, i-kinetics yokusabela, ukuziphatha kwesigaba, kunye nokuhamba kwamandla kwinqanaba ngalinye, okuvumela ukuqinisekiswa ngokukhawuleza kokusebenza kwesityalo phantsi kweemeko ezahlukeneyo. Ukusebenza kakuhle kwamandla, isivuno se-EDC-to-VCM, kunye nemithwalo yokusingqongileyo ilungiswa rhoqo kusetyenziswa idatha yokulinganisa, ixhasa iinjongo zoqoqosho kunye nezomthetho zetekhnoloji yenkqubo ye-vinyl chloride monomer ephucukileyo.
Imisebenzi ebalulekileyo yeYunithi kwiVenkile yeVCM
Ukwenziwa kunye nokuHlanzwa kwe-EDC
Ukwenziwa kwe-EDC kusebenzisa iindlela ezimbini ezihambelanayo zokusabela—i-chlorination ethe ngqo kunye ne-oxychlorination—nganye ineemfuno ezahlukeneyo zokusebenza. Kwi-chlorination ethe ngqo, ukuxubana kwe-ethylene kunye ne-chlorine okulawulwa kakuhle kwenzeka kwi-reactor yesigaba solwelo, kunye nolawulo lobushushu ukuze kuthintelwe ukwakheka okugqithisileyo kwemveliso ephumayo. Xa ifudunyezwa nge-exothermically, le reactor ifuna ukupholisa okuhlanganisiweyo kunye nokwahlukana kwesigaba segesi ukukhusela ukusebenza kakuhle kokuguqulwa.
I-Oxychlorination isebenzisa i-reactor yebhedi esisigxina okanye ibhedi enyibilikisiweyo, isebenzisa i-catalyst ye-copper chloride exhaswa kwi-alumina. I-Ethylene, i-hydrogen chloride ephinda isetyenziswe, kunye ne-oxygen ziyaxutywa kwaye zisabela kwi-200–250°C. Le nkqubo ivelisa zombini i-EDC kunye nomphunga wamanzi. Ulawulo lobushushu olucokisekileyo kunye nokulinganisela kwe-stoichiometric kunciphisa iimveliso ezinobungozi ze-chlorine.
Imijelo ye-EDC ekrwada edityanisiweyo evela kuzo zombini iindlela ihlanjululwa ngokwezigaba. Amanyathelo okuqala asusa amanzi enziwe ngexesha le-oxychlorination ngokusebenzisa ukwahlulwa kwesigaba kunye ne-distillation. Iikholamu zesibini zisusa iikhompawundi ezikhaphukhaphu (ezifana ne-chloroform) kunye neziphelo ezinzima, nto leyo ebangela ubunyulu be-EDC obufanelekileyo kwi-pyrolysis esebenza kakuhle. Iilophu zokuphinda zisetyenziswe zibuyisela izinto ezingaguqukiyo kunye neemveliso ezingasemva, ziphucula ukusetyenziswa kwezinto ezikrwada kolu lungiselelo luvaliweyo.
Ukuqhekeka kobushushu ukuya kwiVinyl Chloride
Ukuqhekeka kobushushu, okanye i-pyrolysis, yingxaki yokuvelisa i-VCM. Apha, umphunga we-EDC ococekileyo kakhulu ufudunyezwa ukuya kuma-480–520°C ngaphakathi kwesithando somlilo esityhubhu, odla ngokufudunyezwa ngokungathanga ngqo ukuze kuzinziswe i-gradients yobushushu kwaye kuthintelwe iindawo ezishushu. Le mpendulo ye-endothermic ephezulu iqhekeza i-EDC ukuze yenze i-vinyl chloride monomer kunye ne-hydrogen chloride nge-free-radical mechanism.
Izinto eziphambili ezitshintshayo kwinkqubo—ubushushu, ixesha lokuhlala, kunye noxinzelelo—zilungiswa kusetyenziswa iinkqubo zolawulo lwenkqubo eziphambili kunye neemodeli zokulinganisa. Ubushushu obugqithisileyo bunokukhuthaza ukungcoliswa kwepolymeric kunye nokwakheka kwemveliso efana ne-tar okanye iikhompawundi ezixineneyo ze-chlorine. Ukucima ngokukhawuleza emva kokuqhekeka kumisa iimpembelelo ezingalindelekanga kwaye kufinyeze amaqhezu emveliso aluncedo. Uhlalutyo lwenkqubo lulandelela ukuveliswa kwe-HCl, edla ngokubuyiselwa kwaye ibuyiselwe kwi-oxychlorination.
Ukucocwa kweVCM kunye nokuHlanjululwa
Ukucocwa kwe-downstream kubalulekile ukuze kufunyanwe ubumsulwa be-vinyl chloride monomer ephezulu. Ukwahlulwa kwegesi kunye nolwelo kususa amanzi kunye neentsalela ezinzima ngaphambi kweekholamu eziphambili ze-distillation. Inkqubo ye-vinyl chloride monomer distillation isebenza phantsi koxinzelelo olucokisekileyo kunye nolawulo lobushushu, iqinisekisa ukwahlukana kwi-EDC engaphendulwanga, i-HCl, kunye ne-azeotropes kunye nezinye izinto eziphilayo ze-chlorine.
Uxinzelelo lwekholamu kunye nomlinganiselo we-reflux zilungiselelwe ukulinganisela ukusetyenziswa kwamandla ngokuchasene neenjongo zobumsulwa—i-reflux ephezulu iphucula ukwahlukana ngexabiso lomphunga kunye namandla okupholisa. Iinkqubo ze-multi-effect condensation kunye ne-reboiler ziphucula ukusebenza kakuhle, ingakumbi xa zidityaniswe nokubuyiselwa kobushushu okudibeneyo.
Ngaphaya kokwahlulwa ngokwasemzimbeni, amaqhinga okulawula inkqubo aphambili avumela uhlengahlengiso lwexesha langempela kwiimeko zekholamu, ukuphendula kutshintsho lwe-feedstock okanye iziganeko ezingaqhelekanga. Uvavanyo lomngcipheko wobungakanani luxhasa ukhuseleko lokusebenza, luxhasa ukubonwa kokuvuza kunye nokunciphisa ukukhutshwa komoya okubalulekileyo kule khemikhali eguquguqukayo. Ukuphunyezwa kwezisombululo zokulinganisa kwi-intanethi, ezifana noxinano oluphakathi kunye neemitha ze-viscosity ezivela eLonnmeter, zibonelela ngokujonga ngokuchanekileyo, ngexesha langempela okubalulekileyo kumgangatho wemveliso kunye nokusebenza ngokukhuselekileyo.
Iipropati zeMvelo nezeKhemikhali eziNxulumene neMveliso yeVCM
Uxinano lolwelo lwe-VCM kunye noLawulo lolwelo lwe-VCM
Uxinano lolwelo lwe-VCM luyahluka kakhulu ngokweqondo lobushushu kunye noxinzelelo—inguqu ebalulekileyo yokusebenza ekuphathweni nasekugcinweni kwe-vinyl chloride monomer. Kwiimeko eziqhelekileyo (20°C), uxinano lwe-vinyl chloride monomer ludla ngokuxelwa njenge-0.911–0.913 g/cm³. Njengoko ubushushu bunyuka, uxinano luyehla, nto leyo echaphazela amazinga okuhamba kwe-volumetric kunye nokubalwa kwetanki.
Umzekelo, kwi-0°C, uxinano lunokunyuka luye kwi-0.930 g/cm³, ngelixa kwi-50°C lusondela kwi-0.880 g/cm³. Olu tshintsho lufuna uhlengahlengiso lwezixhobo zokudlulisa kunye nokubeka esweni inkqubo ngononophelo, njengoko utshintsho luchaphazela amanyathelo enkqubo ye-PVC polymerization. Iimitha zoxinano lolwelo ezikwi-inline yeLonnmeter zihlala zisetyenziswa kwezi sekethe ukuze kuqinisekiswe ngokuqhubekayo, zixhasa ulawulo lwempahla kunye nokudluliselwa kokugcinwa ngokubonelela ngokufundwa okukhawulezileyo kwiimeko zenkqubo ezitshintshayo.
Iimpawu zokunyibilika kwe-vinyl chloride engamanzi nazo zibalulekile. I-VCM ayinyibiliki kakhulu emanzini kodwa ixutywa kakhulu nezinyibilikisi zendalo, nto leyo echaphazela ukhetho lwezinto zokuthintela kunye namanyathelo okunciphisa ungxamiseko ngexesha lokuphathwa nokugcinwa.
Ulawulo loKhuseleko kunye nokusiNgqongileyo
I-vinyl chloride lulwelo oluvutha kakhulu kunye nomphunga, olune-flashpoint ephantsi njenge--78°C kunye noluhlu olubanzi lokuqhuma. Ubuthi bayo obukhulu kunye nokuba yingozi komhlaza okuqatshelweyo kufuna amanyathelo angqongqo okhuseleko lwe-vinyl chloride monomer. Kuyilo lwenkqubo, imibhobho ephindwe kabini, i-nitrogen blanketing, kunye neenethiwekhi ezininzi zokufumanisa ukuvuza ziyasetyenziswa kuyo yonke inkqubo yokwenziwa kwe-vinyl chloride monomer.
Uthutho kunye nokugcinwa kusebenzisa iinqanawa ezikumgangatho ophezulu woxinzelelo ezixhotyiswe ngeenkqubo zokunceda kunye neendawo ezifrijiweyo ukunciphisa uxinzelelo lomphunga kwaye ngaloo ndlela kukhululwe umngcipheko. Iinkqubo zokubeka esweni ukukhutshwa komoya ngexesha langempela kunye nokugcinwa kwazo zisebenza zombini ukhuseleko lomsebenzi kunye nokuthobela imiqathango yokusingqongileyo. Kwimilambo engenisa umoya, iinkqubo zokucoca kunye nezixhobo zokutshisa zinciphisa ukukhululwa kwee-hydrocarbons ezine-chlorine, zithobela imigangatho yokulawula eguqukayo kwimisebenzi yeekhemikhali zoshishino. Ucwangciso olungxamisekileyo kunye nokuqhuba rhoqo kuseyimisebenzi eyimfuneko kuzo zonke izityalo zanamhlanje ze-VCM, ngenxa yokuba kunokwenzeka ukuba kubekho iingozi zokuchatshazelwa ngokukhawuleza nangokungapheliyo ezinxulumene nale khompawundi.
Ukuphuculwa kweNkqubo kunye nokuPhuculwa kokuSebenza kakuhle
Ukuphucula Amandla kunye noHlanganisa
Ukuhlanganiswa kobushushu kube yindlela ephambili kuyilo lwenkqubo yokuvelisa i-vinyl chloride monomer. Uhlalutyo lwe-pinch yindlela esisiseko yokwenza imaphu yemijelo yenkqubo eshushu nebandayo, ityhila indawo yokuxinana—ingxaki yobushushu apho ukubuyiselwa kobushushu kwandiswa khona. Kwisityalo esiqhelekileyo se-vinyl chloride monomer, imijelo emikhulu efuna ukupholisa, efana ne-EDC pyrolysis effluent, ifaniswa nemijelo efuna ukufudumala, efana nee-reboilers kumanyathelo okucoca i-VCM. Ii-composite curves eziphumayo zinceda ekumiseleni iimfuno ezisezantsi zokusetyenziswa kobushushu nebandayo, ukuqinisekisa ukuba inkqubo isebenza kufutshane nemida yayo yokusebenza kakuhle kwe-thermodynamic.
Iinethiwekhi zokutshintsha ubushushu ezilungisiweyo (ii-HEN) zibuyisela ubushushu kwimithombo eshushu ephumayo ukuze zifudumale ngaphambi kokuba ukutya okubandayo okungenayo kufudumale. Oku kusetyenziswa kwakhona kwamandla ngendlela ecwangcisiweyo kunciphisa iindleko zombane kunye nokupholisa nge-10–30% xa kusetyenziswa ngokungqongqo, njengoko kubonisiwe kwizifundo zezityalo zeVCM ezipheleleyo. Usetyenziso lokubuyisela izinto kwakhona luqhelekile, luvumela izixhobo ezikhoyo ngokongeza ii-exchangeers ezifanayo okanye ukulungisa kwakhona ukuhamba ngaphandle kwexesha elibalulekileyo lokungasebenzi. Olu setyenziso lucwangcisiweyo, oluqinisekiswe nge-steady-state simulation, luqinisekisa ukuba ukonga amandla kuyabonakala ngelixa kugcinwa iindleko zemali ziphakathi.
Ukuhlanganiswa okusekwe kwi-pinch kwenza okungaphezulu kokunciphisa iindleko zokusebenza. Kukwatshintsha ukusebenza kokusingqongileyo ngokubanzi—ukutsha kancinci kwepetroli kuthetha ukukhutshwa kwe-CO₂ okuphantsi, okuxhasa ukuthotyelwa kwemithetho yokukhupha ukungcola. Ukonga ukukhutshwa kokungcola kudla ngokulingana namandla agciniweyo; izityalo zibika ukwehla kwe-CO₂ ukuya kuthi ga kwi-25% ukusuka kwicandelo le-VCM kuphela emva kokuhlaziywa kwe-HEN okuqinisekiswe luhlalutyo lwe-composite curve.
Iindlela zokuphucula iinkqubo eziPhambili
Ukulinganisa iinkqubo kuxhasa ukwenziwa ngcono kwendlela yokuvelisa i-vinyl chloride monomer. Besebenzisa ukulinganisa okuzinzileyo, iinjineli ziyila kwaye zilinganise iiyunithi ezintsha, bavavanya iimeko ezininzi zokusebenza, kwaye baqinisekise ukuba ibhalansi yamandla kunye nezinto ziqinile. Oku kuqinisekisa ukusebenza okuqinileyo kuzo zonke iinguqulelo zenkqubo kunye namazinga emveliso alindelekileyo.
Ukuphucula iinjongo ezininzi, kusetyenziswa iindlela ezifana ne-algorithms yemfuza, kulungelelanisa izinto eziphambili ezikhuphisanayo. Kwimisebenzi ye-VCM, iinjongo eziphambili kukuvelisa imveliso, ukusetyenziswa kwamandla amancinci, kunye nokunciphisa ukukhutshwa kwegesi ezigcina ubushushu. Iindlela zanamhlanje zidibanisa ucwangciso lwezibalo nolwazi lwenkqubo ye-heuristic ukuvelisa ulwakhiwo lwezityalo olusebenzayo noluguquguqukayo. Ezi ndlela zihlala zibonelela ngezisombululo ngokuphucula ukubuyiselwa kobushushu ngelixa zigcina imigangatho yokukhupha kunye nobunyulu bemveliso ebalulekileyo kumanyathelo enkqubo ye-PVC polymerization esezantsi.
Uhlengahlengiso oluphindaphindayo lubalulekile. Emva kokuba uqwalaselo lokuqala lwe-HEN lukhethiwe ngokulinganisa, uhlalutyo lwedatha yesityalo kunye nokubeka esweni kwedijithali kubonelela ngovavanyo lokusebenza ngexesha langempela. Abaqhubi banokwenza uhlengahlengiso oluncinci—njengokulungisa amazinga okuhamba kweenkqubo okanye ukwabiwa komsebenzi wotshintshiselwano lobushushu—ngokusekwe kwidatha yobushushu bokwenyani kunye nokwakheka. Olu tshintsho lwempendulo luqinisekisa ukusebenza rhoqo kufutshane neendawo ezimiselweyo zoyilo olulungisiweyo nokuba i-feedstock okanye imfuno yemveliso itshintsha.
Izixhobo ezifana neemitha zoxinano oluphakathi kunye neemitha zoxinano oluvela eLonnmeter zibonelela ngokulinganisa ngokuthe ngqo iimpawu zolwelo ngexesha langempela. Ezi zilinganiso zichonga ukuphambuka okunokuvela ngenxa yokungcola, ukuphazamiseka kwenkqubo, okanye izixhobo zokutya ezingaqhelekanga. Ngedatha echanekileyo, yoxinano oluphakathi kunye ne-viscosity, abaqhubi bagcina iinjongo zokusebenza ezibekiweyo ngexesha loyilo kunye nezigaba zokugunyazisa.
Uvavanyo lwezoQoqosho kunye neeMetriki zokuZinza
Uvavanyo olupheleleyo lwezoqoqosho kwisityalo se-VCM lubala utyalo-mali lwemali, iindleko zokusebenza, kunye nexesha lokuhlawula. Inkcitho yokuqala yemali ibandakanya iindleko zabatshintshi abatsha, iipayipi, kunye neenkqubo zokuphinda zijikeleze ezifunekayo ukuphumeza okanye ukulungisa inethiwekhi yesitshintshi sobushushu. Kwizinto eziphinda zilungiswe, iindleko zemali ezongezelelekileyo zihlala ziphantsi kuba izixhobo ezinkulu zenkqubo zisetyenziswa kwakhona okanye ziphinde zisetyenziswe. Ukonga iindleko zokusebenza—ngokukodwa amandla—kudla ngokukhawulezisa utyalo-mali phakathi kweminyaka eli-1-3, ngakumbi kwimimandla enamaxabiso aphezulu egesi yendalo okanye umphunga.
Iimetrikhi zozinzo kwinkqubo yokuvelisa i-vinyl chloride monomer ziquka okungaphezulu kokusetyenziswa kwamandla. Amanyathelo aphambili aquka ukusebenza kakuhle kwezixhobo ngokubanzi, ukukhutshwa kwe-CO₂ ngetoni yemveliso, kunye nokusetyenziswa kwamanzi kwiisekethe zokupholisa. Uhlalutyo lwezifundo zamva nje luqinisekisa ukuba ukuphuculwa kwe-HEN okuphumelelayo kuhlala kuqhuba uphuculo kwezi metrikhi. Ukufakwa kwezixhobo zizonke ngetoni ye-VCM kuyawa, ukukhutshwa kwemveliso kuyahla, kwaye ukuthotyelwa kwemigaqo-nkqubo yokubika uzinzo kuyaphucuka.
Iimeko zokuhlawula zihlala zichaphazela ukonga ngokuthe ngqo kweenkonzo kunye neenzuzo ezingathanga ngqo ezifana namatyala aphantsi erhafu yekhabhoni kunye neendleko ezimbalwa zemvume yokukhupha ukungcola. Kwimimandla enoxinzelelo olukhulayo lolawulo, amandla esityalo se-vinyl chloride monomer ukubonisa uphuculo oluqhubekayo kwezi milinganiselo anefuthe elikhulu ekusebenzeni ixesha elide kunye nokukhuphisana.
Ngamafutshane, ukwenziwa ngcono kwenkqubo kunye nokuhlanganiswa kwamandla—okusekelwe kukulinganisa okuphucukileyo, ukulungiswa kweenjongo ezininzi, kunye nokulinganisa ngokuthe ngqo (njengaleyo inikwe amandla yitekhnoloji yeLonnmeter)—yinjongo ephambili yoyilo lwesityalo se-vinyl chloride monomer sanamhlanje, esisebenzayo, nesizinzileyo.
Ukwenziwa kwePolyvinyl Chloride (PVC) Polymerization kusetyenziswa iVCM
Intshayelelo kwiNkqubo yePolymerization yePVC
I-vinyl chloride monomer (VCM) yeyona nto ibalulekileyo ekwakheni i-polyvinyl chloride (PVC). I-vinyl chloride polymerization reaction iguqula olu lwelo luguquguqukayo, olungenambala lube yenye yeeplastiki ezisetyenziswa kakhulu kwihlabathi. I-PVC polymerization yenziwa kakhulu kusetyenziswa iindlela zokumiswa kunye ne-emulsion.
Kwiinkqubo yokwenza i-polymerization yokumiswa, i-VCM isasazwa emanzini ngoncedo lwee-agents ezixhomayo ezifana ne-polyvinyl alcohol okanye i-methyl cellulose. Inkqubo iqala ngokushukuma okuphezulu ukuze kuveliswe amathontsi amancinci e-VCM axhonywe kwisigaba samanzi. Emva koko kungeniswa ii-polymerization initiators, ezidla ngokuba yi-organic peroxides okanye ii-azo compounds. Phantsi kobushushu obulawulwa ngokuchanekileyo (ngokuqhelekileyo yi-40–70°C), amathontsi e-VCM ayenza i-polymer, enze ii-beads okanye amasuntswana e-PVC. Ibhetshi ibanjwa phantsi kokushukuma, kwaye izinga lokuphendula lilawulwa luhlobo lomqalisi, uxinaniso, kunye neprofayili yobushushu. Ukulungiswa ngononophelo kwezi parameters kubalulekile ukuqinisekisa ukusasazwa kobukhulu be-particle obuncinci nobufanayo. Xa kugqityiwe, umxube we-reaction uyapholiswa, i-VCM engaphendulwanga iyasuswa, kwaye ii-agents ezizinzisayo okanye ii-modifiers zinokungeniswa ngaphambi kwezigaba ezilandelayo zokuhluza, ukuhlamba, kunye nokomisa.
Iindlela yokwenza i-emulsion polymerizationisebenza ngeemfuno ezahlukeneyo. Apha, i-VCM ixutywa emanzini kusetyenziswa ii-surfactants (iimolekyuli ezifana nesepha), zenza ubungakanani obuncinci kakhulu bamaconsi xa kuthelekiswa nenkqubo yokumiswa. Le ndlela ivelisa i-PVC latex—i-colloidal dispersion efanelekileyo kwizicelo ezikhethekileyo, ezifana neengubo okanye ii-synthetic leathers. Iinkqubo zokuqala zihlala zixhomekeke kwii-redox pairs, ezisebenza kumaqondo obushushu aphantsi. I-Emulsion polymerization ivumela ulawulo olucokisekileyo lweempawu zee-particle, ezifana ne-morphology kunye ne-porosity, nangona ibandakanya amanyathelo anzima okubuyisela imveliso esezantsi.
Itekhnoloji yanamhlanje ye-PVC polymerization idla ngokuhlanganisa izixhobo zokujonga kwindawo ethile, ezifana nee-particle size analyzers okanye ii-in-line density meters (njengoko zenziwe yiLonnmeter), kwinkqubo. Ezi zixhobo zibonelela ngempendulo yexesha langempela, zivumela uhlengahlengiso oluqhubekayo kwisantya sokushukuma, ubushushu, kunye nokutya komqalisi, ngaloo ndlela kuphucula ukuhambelana kwemveliso kunye nokunciphisa inkunkuma.
Iiparameter zoMgangatho weVCM zoMveliso wePVC oSebenzayo
Ukusebenza kakuhle kunye nomgangatho wokwenziwa kwePVC kunxulumene kakhulu neempawu zomzimba nezekhemikhali zeVCM. I-VCM ecocekileyo kakhulu ibalulekile kwi-polymerization ephumelelayo kunye nokusebenza kakuhle kwe-polymer esezantsi.
Ukungcola okukhoyo kwi-VCM—njengamanzi aseleyo, i-acetylene, izinto eziphilayo ezi-chlorine, okanye ii-ion zesinyithi—kunokufaka ityhefu kwiziqalisi, kuthintele amazinga e-polymerization, kwaye kungenise iziphene kwi-resin ye-PVC. Umzekelo, ubukho bee-hydrocarbons ezine-chlorine ezilandelelanayo, nokuba zikwi-parts-per-million concentrations, kunokutshintsha i-kinetics ye-reaction okanye kubangele imveliso engafaniyo nombala. Iinkqubo ezisebenzayo zokucoca i-vinyl chloride monomer zenziwa phezulu, kusetyenziswa iindlela ezifana ne-multi-stage distillation (esebenza kwii-VCM distillation towers ezizinikeleyo) ukunciphisa ukungcola ukuya kwimida eyamkelekileyo.
Iipropati ezibonakalayo—ngokukodwa uxinano lwe-VCM kunye nolawulo lwayo—zidlala indima ethe ngqo ekuphatheni nasekuphindeni kwenkqubo. Uxinano lolwelo lwe-VCM luyahluka kakhulu ngokweqondo lobushushu, nto leyo echaphazela ukuchaneka kwedosi, ukuziphatha kwesigaba ngexesha le-polymerization, kunye nokusebenza kakuhle kwe-agitation. Umzekelo, kwi-0°C, uxinano lwe-VCM lumalunga ne-1.140 g/cm³, luhla ngokunyuka kobushushu. Ukubeka iliso okuthembekileyo, ngexesha langempela koxinano lolwelo lwe-VCM (kusetyenziswa iimitha zoxinano ezikwi-inline ezifana nezo zivela kwi-Lonnmeter) kuqinisekisa umlinganiselo wokutya ochanekileyo, kwenza ukubalwa kokudluliselwa kobushushu kube ngokuchanekileyo, kwaye kuxhasa ukufana kwemveliso yebhetshi ukuya kwibhetshi eqinileyo.
Izinto ezingcolisayo eziseleyo, ingakumbi i-VCM engaphendulwanga, zinokubeka emngciphekweni ukhuseleko kunye nomgangatho wemveliso. Amanqanaba aphezulu e-VCM ekhululekileyo kwi-PVC egqityiweyo azisa iingozi ezinobungozi kwaye anokuchaphazela kakubi iimpawu ezifana nokubola, amandla oomatshini, kunye nozinzo lombala. Imithetho idla ngokuyalela amanyathelo okukrazula apheleleyo kunye nokubeka iliso rhoqo kwi-VCM kulo lonke umjikelo wemveliso ukuqinisekisa imveliso ekhuselekileyo nehambelanayo.
Impembelelo yomgangatho we-VCM kwi-PVC ichazwe kakuhle kwitshathi elandelayo:
| Uphawu loMgangatho weVCM | Impembelelo kwiNkqubo kunye neMveliso yePVC |
| Ubunyulu (ukwakheka kweekhemikhali) | Ichaphazela ngokuthe ngqo izinga le-polymerization, ukusasazwa kobunzima be-molecular, umbala, kunye nokuzinza kobushushu |
| Imeko ebonakalayo (ubuninzi bolwelo) | Ichaphazela ukuchaneka kwedosi, ukusebenza kakuhle kokuxuba, kunye nemo yepolymer |
| Umxholo wokungcola | Ikhokelela ekucinyweni kwesixhobo sokuqala, ukuthintela ukusabela, kunye neempawu ezimbi zoomatshini/zokusetyenziswa kokugqibela |
| Iintsalela (umz., amanzi, izinto eziphilayo) | Ingabangela iziphene ze-porosity, i-evenly particle morphology, kunye neengxaki zokucubungula ezisezantsi |
Ukuqinisekisa ulawulo oluqinileyo lomgangatho we-VCM ngokucoca okuphucukileyo, ukugcinwa ngokufanelekileyo, kunye nobuchwepheshe bokulinganisa uxinano ngexesha langempela kubalulekile kuyilo lwesityalo se-vinyl chloride monomer olusebenzayo kunye nokuhlangabezana namanyathelo okhuseleko afunekayo kubuchwepheshe benkqubo ye-vinyl chloride monomer yanamhlanje.
Imibuzo ebuzwa qho
Yintoni inkqubo ye-vinyl chloride monomer?
Inkqubo yokuvelisa i-vinyl chloride monomer lulandelelwano lwemizi-mveliso oluguqula i-ethylene ibe yi-vinyl chloride monomer (VCM), isitokhwe esibalulekileyo sokwenza i-PVC resin. Iqala ngokufaka i-chlorine kwi-ethylene, yenze i-ethylene dichloride (EDC), ngokuqhelekileyo ngokusebenzisa i-chlorination ethe ngqo okanye i-oxychlorination. Okulandelayo, i-EDC ecocekileyo kakhulu iqhekeka ngobushushu kwii-oven kwi-480–520°C, ivelisa i-VCM kunye ne-hydrogen chloride (HCl). Ngaphantsi komsinga, ii-distillation towers ezininzi zicoca i-VCM, zisusa ukungcola namanzi ukuze zinike ubunyulu obungaphezulu kwe-99.9% obuyimfuneko kwi-polymerization. Ubunzima kunye noqwalaselo lwe-vinyl chloride monomer flow diagram ixhomekeke kuyilo lwezityalo, iinjongo zokusebenza kakuhle, kunye nokuhlanganiswa kwenkunkuma.
Isityalo se-vinyl chloride monomer siqinisekisa njani ukhuseleko kunye nokuthobela imiqathango yokusingqongileyo?
Ngenxa yokuba i-VCM inokutsha, ibangela umhlaza, kwaye inobungozi kokusingqongileyo, uyilo lwesityalo se-vinyl chloride monomer lubeka phambili ukuxinana kunye nokunciphisa. Izibonelelo zisebenzisa izisombululo zokulawula ukukhutshwa komoya ezininzi ukuze zithintele umphunga we-organochlorine. Iinkqubo zokufumanisa ukuvuza ngokuzenzekelayo kunye neenkqubo zokuvala inkqubo zithintela ukukhutshwa ngengozi. Iindawo ezibalulekileyo zisebenzisa izitywina eziqinileyo ngegesi kunye neeyunithi zokunciphisa umoya. Imveliso ephuma kwi-HCl iyaphinda isetyenziswe okanye inyangwe ukunciphisa ukungcola. Ukucima emva kokuqhekeka kwe-EDC kuyayeka ukwakheka kwe-dioxin. Ukuthobela umthetho kuqinisekiswa ngokujonga okudibeneyo ngexesha langempela kunye nokunamathela kwimida yolawulo kwimiphunga yomoya namanzi.
Yintoni i-vinyl chloride engamanzi, kwaye kutheni uxinano lwayo lubalulekile?
I-vinyl chloride engamanzi yindlela exineneyo, ecinezelweyo ye-VCM—igcinwa kwaye ithuthwe kubushushu obuphantsi okanye kuxinzelelo oluphezulu ukuthintela ukufuma. Ubuninzi be-vinyl chloride engamanzi, edla ngokuba phakathi kwe-0.910 ukuya kwi-0.970 g/cm³ kuxhomekeke kubushushu kunye noxinzelelo, yiparameter ebalulekileyo yokuyila iinqanawa zokugcina, ii-tanker zendlela, kunye nemigca yokudlulisa. Idatha yobuninzi bolwelo be-VCM ikwabalulekile ekulandeleni izinto, imisebenzi yokuxuba, ibhalansi echanekileyo yobunzima, kunye nokuqinisekisa isivuno senkqubo kuyo yonke indlela yokusebenza kwemveliso. Iimitha zoxinano ezingaphakathi, ezifana nezo zenziwe yiLonnmeter, zibonelela ngovavanyo oluqhubekayo olufunekayo kukhuseleko lokusebenza kunye nokusebenza kakuhle.
Kutheni inqaba yokunyibilikisa ibalulekile kwinkqubo yokucoca iVCM?
Iinqaba zokunyibilikisa zibalulekile kwinkqubo yokuhlanjululwa kwe-vinyl chloride monomer. Zahlula i-VCM kwi-EDC eseleyo, ukungcola okune-chlorine ebila kancinci, kunye "neziphelo ezinzima" ezenziwe ngexesha lokuveliswa. Ukusebenza kakuhle kwenqaba yokunyibilikisa i-VCM kuqinisekisa ukuba i-monomer yokunyibilikisa i-polymerization ihlangabezana nemigangatho engqongqo yomgangatho. Naluphi na ungcoliseko, olufana neekhompawundi ezingagcwaliyo okanye ukufuma, lunokuthintela amanyathelo enkqubo yokunyibilikisa i-PVC, lubangele i-resin engaqhelekanga, okanye lonakalise ii-catalysts ezisezantsi. Iindlela eziphambili zokuhlanjululwa kwe-VCM zisebenzisa ii-rectifiers ezineempembelelo ezininzi kunye neetreyi ezikhethekileyo ukuze kuphuculwe ukwahlukana, kubuyiselwe imveliso, kwaye kuncitshiswe ukungcola kwe-reboiler.
Inkqubo yokwenza i-PVC polymerization inxulumene njani nemveliso ye-vinyl chloride monomer?
Ubunyulu kunye nokuzinza kwe-VCM zizinto ezifunekayo ukuze kubekho ii-resin ze-polyvinyl chloride ezikumgangatho ophezulu. Inkqubo ye-PVC polymerization isebenzisa ngokuthe ngqo i-VCM kwii-reactors ze-polymerization (ngokusebenzisa i-suspension, i-emulsion, okanye iteknoloji ye-bulk). Ulawulo oluchanekileyo lokwakheka kwe-VCM luchaphazela ulwakhiwo lweemolekyuli, iiprofayili zokungcola, kunye neepropati zomzimba zeemveliso zokugqibela ze-PVC. Unxibelelwano olusondeleyo phakathi kwenkqubo yokwenziwa kwe-vinyl chloride monomer kunye netekhnoloji ye-PVC polymerization kuthetha ukuba naluphi na utshintsho lwenkqubo kwi-VCM—njengokwahluka koxinano, ukungcola okulandeleleneyo, okanye ukufudumala kobushushu—lunokukhula luye kwinqanaba le-polymerization, luchaphazela ukusebenza kakuhle kunye nokusebenza kwemveliso.
Ixesha leposi: Disemba-18-2025
