Kumvetsetsa Njira ya Vinyl Chloride Monomer
Vinyl chloride monomer (VCM) ndi mwala wapangodya wa makampani amakono apulasitiki, zomwe zimapangitsa kuti pakhale maziko ofunikira popanga polyvinyl chloride (PVC). Monga mankhwala opangidwa ndi zinthu zosiyanasiyana, VCM imagwiritsidwa ntchito kokha polima PVC, zomwe zimathandiza kupanga chilichonse kuyambira zida zamankhwala ndi zipangizo zomangira mpaka zokutira za waya ndi zinthu zogwiritsidwa ntchito ndi anthu. Kufunika kwa VCM kumagwirizana kwambiri ndi kutulutsa kwa PVC padziko lonse lapansi, zomwe zimapangitsa kuti kupanga kwake kotetezeka, kogwira mtima, komanso kotetezeka kukhale kofunika kwambiri m'mafakitale.
VCM ndi mpweya wopanda mtundu, woyaka kwambiri pamalo ozungulira, womwe nthawi zambiri umayendetsedwa ngati madzi opanikizika m'malo osankhidwa. Kapangidwe kake ka mankhwala, CH₂=CHCl, kamapangidwa ndi gulu la vinyl lolumikizidwa ndi atomu imodzi ya chlorine. Kapangidwe ka mamolekyu kameneka kamalola polymerization yosavuta, mawonekedwe a reactivity omwe amathandizira vinyl chloride polymerization reaction yofunika kwambiri mu njira ya PVC polymerization. Kapangidwe ka thupi ka vinyl chloride yamadzimadzi—monga kutentha kwa −13.4°C ndi kuchuluka kwa 0.91 g/mL pa 20°C—kumafunikira kuwongolera kolimba kwa njira ndi njira zapadera zosungira zomwe zimasunga mankhwalawo ngati madzi opangira ntchito zopangira vinyl chloride monomer.
Njira ya Vinyl Chloride Monomer
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Kugwiritsa ntchito VCM kunja kwa PVC n'kochepa, zomwe zikusonyeza udindo wake ngati monomer wodzipereka pa polymerization. Chifukwa chake, mbali zonse za kapangidwe ka chomera cha vinyl chloride monomer, kuyambira kapangidwe ka sitima ya reactor mpaka chinthu chomwe chimagwiritsidwa ntchito.kuyeretsandi kubwezeretsa, zimakonzedwa kuti zigwiritsidwe ntchito kwambiri, mosalekeza kuti zipereke ukadaulo wa polymerization wa PVC.
Komabe, kusamalira ndi kusunga VCM kumabweretsa zoopsa zambiri. VCM imayikidwa m'gulu la khansa ya Gulu 1, ndipo umboni wamphamvu umayigwirizanitsa ndi angiosarcoma ya chiwindi ndi zotsatira zina zoopsa paumoyo pambuyo poyikira kwa nthawi yayitali. Kuopsa kwake kumawonjezeka chifukwa cha kupangika kwa ma metabolites ogwirizana, omwe amamanga ma macromolecules a maselo ndikusokoneza njira zamoyo. Kuyikira kwadzidzidzi kumabweretsa kuvutika maganizo kwa mitsempha, pomwe kuwonekera kwa nthawi yayitali kuntchito kumagwirizanitsidwa ndi "matenda a ogwira ntchito a vinyl chloride" - matenda omwe amaphatikizapo kuwonongeka kwa chiwindi, zizindikiro zofanana ndi scleroderma, ndi zilonda zamafupa. Malire olamulira pakuwonekera ndi okhwima: kuyambira mu 2024, Occupational Safety and Health Administration (OSHA) imakhazikitsa malire ovomerezeka a maola 8 a 1 ppm, ndi malire otsika kwambiri omwe akulimbikitsidwa ndi ACGIH ndi NIOSH kuti awonetse kumvetsetsa kwatsopano kwa poizoni.
VCM imayakanso kwambiri, ndipo imatha kuphulika pakati pa 3.6% ndi 33% mumlengalenga. Kuphatikiza kwa poizoni ndi kuyaka kwapangitsa kuti pakhale njira zodzitetezera zolimba m'malo onse opangira VCM. Mizere yogwirira ntchito imatsekedwa mokwanira ndikusungidwa pansi pa mpweya wopanda mpweya—nthawi zambiri nayitrogeni—ndipo njira zodziwira kutuluka kwa madzi nthawi zonse komanso njira zotulutsira mpweya mwadzidzidzi zili pamalopo. Mpweya wotulutsa mpweya m'deralo, malo otchingira njira, zoletsa moto wotseguka, ndi malo olowera olamulidwa bwino zimachepetsa chiopsezo. Madzi a VCM amasungidwa ndikunyamulidwa pansi pa kukakamizidwa m'matanki osakhudzidwa ndi dzimbiri, nthawi zambiri amakhazikika ndi zoletsa polymerization monga phenol kuti ateteze ku zochita zoopsa zomwe zimayambitsidwa zokha.
Njira Zazikulu Zopangira VCM
Kupanga VCM kumayendetsedwa ndi njira ziwiri zazikulu zamafakitale: chlorination yolunjika ndi oxychlorination. Zonsezi zimayang'ana pakupanga ndi kusintha kwa ethylene dichloride (EDC), yomwe ndi gawo lalikulu lapakati lomwe limasweka kuti lipange VCM.
Mu njira yolunjika ya chlorination, ethylene imakumana ndi mpweya wa chlorine mu njira yamadzimadzi yochokera ku exothermic kwambiri, nthawi zambiri pamwamba pa ferric chloride kapena chothandizira chofanana kuti ipange EDC kudzera mu:
C₂H₄ + Cl₂ → C₂H₄Cl₂
Kapenanso, njira ya oxychlorination imaphatikiza ethylene, hydrogen chloride, ndi oxygen pogwiritsa ntchito copper(II) chloride catalyst, ndikupanga EDC ndi madzi:
C₂H₄ + 2HCl + ½O₂ → C₂H₄Cl₂ + H₂O
Njirayi imapereka ubwino wachuma komanso kusinthasintha kwa chakudya mwa kubwezeretsanso HCl yopangidwa panthawi yopanga VCM, zomwe zikanabweretsa mavuto otaya zinyalala.
EDC ikapangidwa, imaphwanyidwa kutentha pafupifupi 500°C, nthawi zambiri mu gawo la nthunzi pamwamba pa pumice kapena ceramic packing, kuti ipange VCM ndi hydrogen chloride:
C₂H₄Cl₂ → CH₂=CHCl (VCM) + HCl
Chogulitsa cha VCM chomwe chimatuluka mu uvuni wosweka chimasakanizidwa ndi chisakanizo chovuta cha zinthu zina ndi zakudya zomwe sizinachite bwino. Magawo angapo oyeretsera—makamakakusungunuka—amagwiritsidwa ntchito polekanitsa, makamaka njira yoyeretsera vinyl chloride monomer. Ntchito ya nsanja yoyeretsera ya VCM ndi njira zolumikizira kutentha zimakonzedwa kuti zikhale zoyera kwambiri (nthawi zambiri >99.9%), zofunika kwambiri pa polymerization yapamwamba ya PVC. Mita yozungulira ngati yomwe imapangidwa ndi Lonnmeter nthawi zambiri imagwiritsidwa ntchito kuyang'anira kuchuluka kwa madzi a VCM pa kutentha kosiyanasiyana, kuthandiza ogwiritsa ntchito kuzindikira mwachangu magulu osadziwika bwino kapena zochitika zodetsa.
Makampani opanga zinthu amakonda mapangidwe ophatikizika omwe amaphatikiza ma reactor a chlorination mwachindunji ndi oxychlorination, kubwezeretsanso kwa hydrogen chloride mogwirizana, ndi njira zobwezeretsanso mphamvu. Mapangidwe osakanikirana awa amathandizira kuchepetsa ndalama zogulira chakudya komanso kugwiritsa ntchito mphamvu bwino. Ukadaulo wamakono wa vinyl chloride monomer umayesetsa kuti pakhale zokolola zambiri, chitetezo, komanso kusinthasintha posamalira zinthu zosiyanasiyana zopangira, pomwe kuyang'anira mosamala zinthu zofunika (kuphatikiza kuchulukana ndi kuyera) m'malo osiyanasiyana opangira zinthu kumatsimikizira kuti PVC ndi yabwino komanso kuti malamulo azitsatiridwa pa thanzi, chitetezo, komanso chilengedwe.
Njira Yatsatanetsatane Yoyendera Mapangidwe a Vinyl Chloride Monomer
Chithunzi cha Njira Yopangira Vinyl Chloride
Kupanga kwa vinyl chloride monomer (VCM) yamakono kumadalira kuyenda kwa njira yogwirizana bwino, yomwe nthawi zambiri imawonetsedwa ndi chithunzi chokwanira chomwe chimawonetsa gawo lililonse lofunikira. Njirayi imayamba ndi zolowetsa zinthu zopangira - makamaka ethylene, chlorine, hydrogen chloride, ndi oxygen. Mu kapangidwe ka chomera cha vinyl chloride monomer, zinthuzi zimayendetsedwa kudzera mu chlorination direct ndi oxychlorination reactors kuti apange ethylene dichloride (EDC), yomwe ndi yapakati.
Mu chlorination yolunjika, ethylene imayanjana ndi chlorine pansi pa kutentha kolamulidwa (40–90°C) kuti ipange EDC. Mofananamo, gawo la oxychlorination limaphatikiza hydrogen chloride (nthawi zambiri imabwezeretsedwanso kuchokera ku njira zina zotsatizana), ethylene, ndi mpweya—pogwiritsa ntchito chothandizira chochokera ku mkuwa pa kutentha kwakukulu (200–250°C) kuti ipange EDC ndi madzi. Njira zonse ziwiri zoyankhira zimagwirizanitsidwa kuti zibwezeretsenso mpweya wosayankhira ndikuwonjezera kuchuluka kwa magwiritsidwe ntchito, ndikupanga maziko a njira yolinganiza yopangira vinyl chloride monomer.
Kuyeretsa EDC yopanda mafuta kumaphatikizapo mizati yoyeretsera yomwe imachotsa madzi, zinthu zina zopangidwa ndi chlorine, ndi zinthu zina zodetsa. EDC yoyeretsedwayo imadyetsa pyrolysis, kapena cracking furnace—njira yomwe imagwira ntchito pa 480–520°C ndi kupanikizika pang'ono. Apa, kutentha kumawononga VCM ndikutulutsa hydrogen chloride, yomwe nthawi zambiri imabwezeretsedwa ku oxychlorination loop. Kuzimitsa ndi kuziziritsa mofulumira kwa mpweya wosweka kumateteza zotsatira zoyipa zosafunikira ndikuwononga mapangidwe a zinthu zoopsa.
Mpweya womwe umachokera umalekanitsidwa ndikuyeretsedwa pogwiritsa ntchito zipilala zina zoyeretsera ndi zolekanitsa magawo. Njira zoyeretsera za VCM zapadera, kuphatikizapo kuyeretsa ndi kuyamwa kwa magawo ambiri, zimaonetsetsa kuti kuyera kwa zinthu nthawi zambiri kumapitirira 99.9%. EDC yosasinthika imabwezeretsedwanso, zomwe zimapangitsa kuti kusinthaku kukhale kosangalatsa komanso kuchepetsa mpweya woipa. Machitidwe oletsa kutayikira ndi kuyang'anira pafupipafupi njira zogwirira ntchito zimateteza ku kutuluka kwa madzi ndikuwonetsetsa kuti zikutsatira malamulo achitetezo a vinyl chloride yamadzimadzi yomwe imatha kuyaka komanso yoyambitsa khansa.
Munthawi yonse yopanga vinyl chloride monomer, kasamalidwe ka mphamvu ndi kubwezeretsa kutentha ndikofunikira kuti zinthu zizikhala bwino. Kutentha kwa exothermic kuchokera ku chlorination ndi oxychlorination kumabwezeretsedwanso, kutenthetsa chakudya chamtsogolo kapena kupanga nthunzi ya process. Kusanthula kwa pinch ndi njira zolumikizira kutentha zimagwiritsidwa ntchito pa ma network osinthira kutentha, kuchepetsa kugwiritsa ntchito mafuta komanso kuwononga chilengedwe.
Mapulatifomu oyeserera njira—makamaka Aspen Plus—ndi ofunikira kwambiri pakupanga, kukulitsa, ndi kukonza. Ma model a digito awa amatsanzira kulinganiza kwa zinthu, kayendedwe ka reaction, kachitidwe ka gawo, ndi kuyenda kwa mphamvu pa sitepe iliyonse, zomwe zimathandiza kutsimikizira mwachangu magwiridwe antchito a chomera pansi pa zochitika zosiyanasiyana. Kugwiritsa ntchito mphamvu moyenera, zokolola za EDC-to-VCM, ndi katundu wokhudzana ndi chilengedwe nthawi zonse zimasinthidwa pogwiritsa ntchito deta yoyeserera, kuthandizira zolinga zachuma komanso zoyang'anira zaukadaulo wapamwamba wa vinyl chloride monomer.
Ntchito Zofunika Kwambiri mu Chomera cha VCM
Kupanga ndi Kuyeretsa kwa EDC
Kupanga kwa EDC kumagwiritsa ntchito njira ziwiri zoyankhira—kutulutsa chlorination mwachindunji ndi oxychlorination—iliyonse yokhala ndi zofunikira zosiyana pakugwira ntchito. Mu chlorination mwachindunji, kusakaniza bwino kwa ethylene ndi chlorine kumachitika mu reactor yamadzimadzi, ndi malamulo a kutentha kuti apewe kupanga zinthu zambiri. Potenthedwa mopanda kutentha, reactor iyi imafuna kuziziritsa kophatikizana ndi kulekanitsa mpweya kuti iteteze magwiridwe antchito.
Oxychlorination imagwiritsa ntchito chosinthira cha bedi lokhazikika kapena chosinthira madzi, pogwiritsa ntchito chothandizira cha chloride cha mkuwa chomwe chimathandizidwa ndi alumina. Ethylene, hydrogen chloride yobwezeretsedwanso, ndi mpweya zimasakanizidwa ndikuyankhidwa pa 200–250°C. Njirayi imapanga EDC ndi nthunzi yamadzi. Kuwongolera kutentha mosamala komanso kulinganiza kwa stoichiometric kumachepetsa zinthu zoopsa zomwe zili ndi chlorine.
Mitsinje ya EDC yosaphikidwa yosakanikirana kuchokera m'njira zonse ziwiri imayeretsedwa pang'onopang'ono. Masitepe oyamba amachotsa madzi omwe amapangidwa panthawi ya oxychlorination kudzera mu gawo lolekanitsidwa ndi distillation. Mizere yachiwiri imachotsa mankhwala opepuka (monga chloroform) ndi malekezero olemera, zomwe zimapangitsa kuti EDC ikhale yoyera bwino kuti igwiritsidwe ntchito bwino kwambiri. Ma loops obwezeretsanso amabwezeretsa zinthu zosasinthidwa ndi zinthu zina, zomwe zimapangitsa kuti zinthu zopangira zigwiritsidwe ntchito bwino mu mawonekedwe otsekedwa awa.
Kutentha kwa Vinyl Chloride
Kutentha kwa ming'alu, kapena pyrolysis, ndiye vuto la kupanga VCM. Pano, nthunzi ya EDC yoyera kwambiri imatenthedwa kufika pa 480–520°C mkati mwa ng'anjo ya tubular, nthawi zambiri imatenthedwa mwanjira ina kuti ikhazikitse kutentha ndikupewa malo otentha. Kuchitapo kanthu kwamphamvu kumeneku kumagawa EDC kuti ipange vinyl chloride monomer ndi hydrogen chloride pogwiritsa ntchito njira ya free-radical.
Zinthu zofunika kwambiri pa ndondomekoyi—kutentha, nthawi yogona, ndi kupanikizika—zimakonzedwa bwino pogwiritsa ntchito njira zamakono zowongolera njira ndi zitsanzo zoyeserera. Kutentha kwambiri kumatha kulimbikitsa kuipitsidwa kwa polymeric ndi kupanga zinthu zina monga phula kapena mankhwala olemera a chlorine. Kuzimitsa mwachangu nthawi yomweyo mutatha kusweka kumayimitsa zotsatira zoyipa ndikuchepetsa magawo othandiza azinthu. Kusanthula njira kumatsata kupanga kwa HCl, komwe nthawi zambiri kumabwezeretsedwa ndikubwezeretsedwa ku oxychlorination.
Kuyeretsa ndi Kutulutsa VCM
Kuyeretsa pansi pa madzi n'kofunika kwambiri kuti pakhale kuyera kwa vinyl chloride monomer. Kulekanitsa gasi ndi madzi kumachotsa madzi ndi zotsalira zolemera musanayambe kusungunuka m'mizere yayikulu. Njira yosungunula vinyl chloride monomer imagwira ntchito mosamala motsogozedwa ndi kutentha, kuonetsetsa kuti kusiyana ndi EDC, HCl, ndi azeotropes zomwe sizinachitike ndi zinthu zina zachilengedwe zomwe zili ndi chlorine.
Kuthamanga kwa mzati ndi ma reflux ratios amakonzedwa kuti agwirizane ndi kugwiritsa ntchito mphamvu motsutsana ndi zolinga za kuyera—reflux yapamwamba imakulitsa kulekanitsa komwe kumawononga mphamvu ya nthunzi ndi kuziziritsa. Makina odzaza ndi ma condensation ambiri ndi ma reboiler amawongolera magwiridwe antchito, makamaka akaphatikizidwa ndi kubwezeretsanso kutentha kophatikizidwa.
Kupatula kulekanitsa thupi, njira zamakono zowongolera njira zimathandiza kusintha nthawi yeniyeni ku mikhalidwe ya mizati, poyankha kusintha kwa chakudya kapena zochitika zina. Kuwunika kuchuluka kwa zoopsa kumathandizira chitetezo cha ntchito, kuthandizira kuzindikira kutayikira ndi kuchepetsa kutulutsa mpweya woipa komwe ndikofunikira kwambiri pa mankhwala osinthasintha awa. Kukhazikitsa njira zoyezera pa intaneti, monga inline density ndi viscosity meters kuchokera ku Lonnmeter, kumapereka kuwunika kolondola komanso nthawi yeniyeni komwe ndikofunikira kuti zinthu ziyende bwino komanso kuti zinthu zizigwira ntchito bwino.
Kapangidwe ka Thupi ndi Mankhwala Ogwirizana ndi Kupanga kwa VCM
Kuchuluka kwa Madzi a VCM ndi Kusamalira Madzi a VCM
Kuchuluka kwa madzi a VCM kumasiyana kwambiri malinga ndi kutentha ndi kupanikizika—chinthu chofunikira kwambiri pakugwira ndi kusunga vinyl chloride monomer. Pazikhalidwe zoyenera (20°C), kuchuluka kwa vinyl chloride monomer nthawi zambiri kumanenedwa kuti ndi 0.911–0.913 g/cm³. Pamene kutentha kukukwera, kuchuluka kumachepa, zomwe zimakhudza kuchuluka kwa madzi ndi kuwerengera kosungira thanki.
Mwachitsanzo, pa 0°C, kuchulukana kumatha kukwera kufika pa 0.930 g/cm³, pomwe pa 50°C kumafika pa 0.880 g/cm³. Kusintha kotereku kumafuna kukonzedwanso kwa zida zosamutsira ndi kuyang'anira mosamala njira, chifukwa kusinthaku kumakhudza njira zoyendetsera polymerization ya PVC. Ma inline liquid density mita a Lonnmeter nthawi zambiri amayikidwa m'mabwalo awa kuti atsimikizire mosalekeza, kuthandizira kuwongolera zinthu ndi kusamutsa zinthu mwa kupereka mawerengedwe nthawi yomweyo pakusintha kwa njira.
Makhalidwe a kusungunuka kwa vinyl chloride yamadzimadzi nawonso ndi ofunikira. VCM imasungunuka pang'ono m'madzi koma imasakanikirana kwambiri ndi zinthu zosungunulira zachilengedwe, zomwe zimakhudza kusankha kwa zinthu zosungiramo ndi njira zochepetsera mavuto panthawi yogwiritsira ntchito ndi kusungira.
Chitetezo ndi Kulamulira Zachilengedwe
Vinyl chloride ndi madzi ndi nthunzi zomwe zimayaka kwambiri, zomwe zimakhala ndi malo oyaka mpaka -78°C komanso zimaphulika kwambiri. Kuopsa kwake kwakukulu komanso kuopsa kwa khansa kumafuna njira zodzitetezera zolimba ku vinyl chloride monomer. Pakupanga, mapaipi okhala ndi makoma awiri, kuphimba nayitrogeni, ndi maukonde ambiri ozindikira kutayikira kwa madzi amagwiritsidwa ntchito panthawi yonse yopanga vinyl chloride monomer.
Kunyamula ndi kusungirako zinthu kumagwiritsa ntchito zombo zoyendetsedwa ndi mphamvu zomwe zili ndi njira zochepetsera kupanikizika komanso malo osungiramo zinthu kuti zichepetse kupanikizika kwa nthunzi ndikutulutsa chiopsezo. Njira zowunikira utsi nthawi yeniyeni komanso zotetezera zimathandiza chitetezo kuntchito komanso kutsatira malamulo a chilengedwe. Pa mitsinje yotulutsa mpweya, makina otsukira ndi zotenthetsera zimachepetsa kutulutsidwa kwa ma hydrocarbons a chlorine, kutsatira miyezo yosinthika ya malamulo pantchito zamafakitale. Kukonzekera zadzidzidzi ndi kubowola nthawi zonse kumakhalabe njira zofunika kwambiri m'mafakitale onse amakono a VCM, chifukwa cha kuthekera kwa zoopsa zomwe zingachitike mwadzidzidzi komanso kwanthawi yayitali zokhudzana ndi mankhwalawa.
Kukonza Njira ndi Kuwongolera Kuchita Bwino
Kukonza Mphamvu ndi Kuphatikizana
Kuphatikiza kutentha kwakhala njira yofunika kwambiri pakupanga njira zopangira vinyl chloride monomer. Kusanthula kwa pinch ndi njira yoyambira yopangira mapu a mitsinje yotentha ndi yozizira, kuwulula malo ofunikira - botolo la kutentha komwe kuchira kutentha kumakulitsidwa. Mu chomera cha vinyl chloride monomer chodziwika bwino, mitsinje yayikulu yomwe imafunikira kuziziritsidwa, monga madzi otuluka a EDC pyrolysis, imagwirizanitsidwa ndi mitsinje yomwe imafunikira kutentha, monga ma reboilers mu njira zoyeretsera za VCM. Ma curve ophatikizika omwe amatsatira amathandizira kudziwa zofunikira zochepa zogwiritsira ntchito kutentha ndi kuzizira, kuonetsetsa kuti njirayi ikugwira ntchito pafupi ndi malire ake a thermodynamic efficiency.
Ma network osinthira kutentha (HENs) okonzedwa bwino amabwezeretsa kutentha kuchokera ku mitsinje yotentha yomwe ikutuluka kuti itenthetse chakudya chozizira chomwe chikubwera. Kugwiritsanso ntchito mphamvu mwadongosolo kumeneku kumachepetsa ndalama zogwiritsidwa ntchito ndi nthunzi ndi kuziziritsa ndi 10–30% zikagwiritsidwa ntchito mwamphamvu, monga momwe zasonyezedwera m'maphunziro a mafakitale a VCM athunthu. Kugwiritsa ntchito zinthu zatsopano ndikofala, komwe kumathandizira zida zomwe zilipo powonjezera zosinthira zofanana kapena kusintha kayendedwe ka madzi popanda nthawi yogwira ntchito kwambiri. Kukhazikitsa kumeneku, komwe kumatsimikiziridwa kudzera mu kuyerekezera kwa steady-state, kumawonetsetsa kuti ndalama zosungira mphamvu zimakhala zogwira mtima komanso kusunga ndalama zoyambira.
Kuphatikizana kochokera ku pinch sikungochepetsa ndalama zogwirira ntchito. Kumasinthanso magwiridwe antchito onse azachilengedwe—kuchepa kwa mafuta oyaka kumatanthauza kuchepa kwa mpweya wa CO₂, kuthandizira kutsatira malamulo okhwima oletsa mpweya woipa. Kusunga mpweya woipa nthawi zambiri kumakhala kofanana ndi kusunga mphamvu; mafakitale amanena kuti CO₂ yatsika ndi 25% kuchokera ku gawo la VCM lokha pambuyo pa kusinthidwa kwa HEN komwe kwatsimikiziridwa ndi kusanthula kwa composite curve.
Njira Zapamwamba Zokonzera Njira
Kuyeserera kwa njira kumathandizira kukonza bwino kayendedwe ka njira zopangira vinyl chloride monomer. Pogwiritsa ntchito kuyeserera kokhazikika, mainjiniya amapanga ndikukulitsa mayunitsi atsopano, amayesa zochitika zingapo zogwirira ntchito, ndikuwonetsetsa kuti mphamvu ndi zinthu zili bwino. Izi zimatsimikizira magwiridwe antchito olimba pakusintha kwa njira ndi kuchuluka kwa kupanga komwe kumayembekezeredwa.
Kukonza zinthu m'njira zosiyanasiyana, pogwiritsa ntchito njira monga ma algorithms a majini, kumalinganiza zinthu zofunika kwambiri. Mu ntchito za VCM, zolinga zazikulu ndi kukolola zinthu, kugwiritsa ntchito mphamvu zochepa, komanso kuchepetsa mpweya woipa womwe umatuluka m'nthaka. Njira zamakono zimaphatikiza mapulogalamu a masamu ndi chidziwitso cha njira yogwiritsira ntchito zinthu kuti apange mapangidwe enieni komanso osinthika a zomera. Njirazi nthawi zambiri zimapereka mayankho okhala ndi kuchira bwino kwa kutentha pamene zikusunga miyezo yotuluka ndi kuyera kwa zinthu zomwe ndizofunikira kwambiri pa njira zoyendetsera polymerization ya PVC.
Kusintha mobwerezabwereza n'kofunika. Pambuyo poti kasinthidwe koyamba ka HEN kasankhidwa kudzera mu kuyerekezera, kusanthula deta ya zomera ndi kuyang'anira digito kumapereka kuwunika magwiridwe antchito nthawi yeniyeni. Ogwiritsa ntchito amatha kusintha pang'ono—monga kusintha kuchuluka kwa kayendedwe ka ntchito kapena kugawa ntchito yosinthira kutentha—kutengera kutentha kwenikweni ndi deta yopangidwa. Kuzungulira kwa mayankho kumeneku kumatsimikizira kugwira ntchito kosalekeza pafupi ndi malo okonzedweratu ngakhale pamene kufunikira kwa chakudya kapena kupanga kukusintha.
Zipangizo monga inline density meters ndi viscosity meters zochokera ku Lonnmeter zimapereka muyeso mwachindunji wa makhalidwe amadzimadzi nthawi yeniyeni. Miyeso iyi imazindikira kupotoka komwe kungachitike chifukwa cha kuipitsidwa, kusokonezeka kwa njira, kapena zinthu zina zodyetsera zomwe sizili zenizeni. Ndi deta yolondola, yeniyeni ya density ndi viscosity, ogwira ntchito amasunga zolinga za magwiridwe antchito zomwe zakhazikitsidwa panthawi yopanga ndi kuyambitsa.
Kuwunika Zachuma ndi Ziwerengero Zokhazikika
Kuwunika kwathunthu zachuma kwa fakitale ya VCM kumawerengera ndalama zomwe zayikidwa, ndalama zogwirira ntchito, ndi nthawi yobwezera. Ndalama zoyambira zomwe zagwiritsidwa ntchito zimaphatikizapo mtengo wa osinthira ndalama atsopano, mapaipi, ndi makina obwezeretsanso omwe amafunikira kuti akhazikitse kapena kukonzanso netiweki yosinthira kutentha. Pazokonzanso, ndalama zowonjezera zomwe zayikidwa zimakhalabe zochepa chifukwa zida zazikulu zogwirira ntchito zimagwiritsidwanso ntchito kapena kugwiritsidwanso ntchito. Kusunga ndalama zogwirira ntchito—makamaka mphamvu—nthawi zambiri kumathetsa ndalama zomwe zayikidwa mkati mwa zaka 1-3, makamaka m'madera omwe ali ndi mitengo yokwera ya gasi wachilengedwe kapena nthunzi.
Ziyeso zokhazikika pakupanga vinyl chloride monomer zimaphatikizapo zambiri kuposa kugwiritsa ntchito mphamvu. Njira zazikulu zimaphatikizapo kugwiritsa ntchito bwino chuma chonse, kutulutsa kwa CO₂ pa tani ya chinthu, ndi kugwiritsa ntchito madzi m'malo ozizira. Kusanthula kwa kafukufuku waposachedwa kumatsimikizira kuti kukonza bwino kwa HEN nthawi zonse kumapangitsa kuti zinthuzi zisinthe. Kutsika kwa VCM, kuchepa kwa mpweya, komanso kutsatira njira zofotokozera zakhazikika kumakula.
Zochitika zobwezera ndalama nthawi zambiri zimakhudza kusunga ndalama mwachindunji komanso phindu losalunjika monga kuchepetsa msonkho wa kaboni komanso kuchepetsa ndalama zotulutsa mpweya zomwe zimalola. M'madera omwe malamulo akukwera, kuthekera kwa chomera cha vinyl chloride monomer kuwonetsa kusintha kosalekeza paziyeso izi kumakhudza kwambiri kuthekera kwa nthawi yayitali komanso mpikisano.
Mwachidule, kukonza njira ndi kuphatikiza mphamvu—kozikidwa pa kuyerekezera kwapamwamba, kukonza zinthu zosiyanasiyana, ndi kuyeza mwachindunji (monga komwe kumayendetsedwa ndi ukadaulo wa Lonnmeter)—ndizo maziko a kapangidwe ka chomera cha vinyl chloride monomer chamakono, chogwira ntchito bwino, komanso chokhazikika.
Polyvinyl Chloride (PVC) Polymerization Pogwiritsa Ntchito VCM
Chiyambi cha Njira Yopangira Polymerization ya PVC
Vinyl chloride monomer (VCM) ndiye chinthu chofunikira kwambiri popanga polyvinyl chloride (PVC). Kupopera kwa vinyl chloride kumasintha madzi osasunthika, opanda mtundu awa kukhala amodzi mwa mapulasitiki omwe amagwiritsidwa ntchito kwambiri padziko lonse lapansi. Kupopera kwa PVC kumachitika makamaka pogwiritsa ntchito njira zoyimitsira ndi zotulutsira madzi.
Munjira yopangira polymerization yoyimitsidwa, VCM imamwazidwa m'madzi pogwiritsa ntchito zinthu zomangira monga polyvinyl alcohol kapena methyl cellulose. Njirayi imayamba ndi kugwedezeka kwakukulu kuti ipange madontho ang'onoang'ono a VCM omwe amamangiriridwa mu gawo lamadzi. Zoyambitsa polymerization, nthawi zambiri ma peroxide achilengedwe kapena mankhwala a azo, zimayikidwa. Pansi pa kutentha kolamulidwa bwino (nthawi zambiri 40–70°C), madontho a VCM amapangidwa polymer, ndikupanga mikanda kapena tinthu ta PVC. Gululo limasungidwa pansi pa kugwedezeka, ndipo kuchuluka kwa zomwe zimachitika kumayendetsedwa ndi mtundu wa woyambitsa, kuchuluka kwake, ndi mawonekedwe a kutentha. Kusintha mosamala magawo awa ndikofunikira kuti muwonetsetse kuti kukula kwa tinthu tating'onoting'ono ndi kofanana kufalikira. Mukamaliza, kusakaniza kwa zomwe zimachitika kumazizidwa, VCM yosakhudzidwa imachotsedwa, ndipo zinthu zokhazikika kapena zosintha zitha kuyikidwa musanayambe kusefa, kutsuka, ndi kuumitsa.
Thenjira yoyeretsera emulsionimagwira ntchito ndi zofunikira zosiyanasiyana. Pano, VCM imapangidwa m'madzi pogwiritsa ntchito ma surfactants (mamolekyu ofanana ndi sopo), ndikupanga madontho ang'onoang'ono kwambiri poyerekeza ndi njira yoyimitsira. Njirayi imapanga PVC latex—kufalikira kwa colloidal komwe kumayenera kugwiritsidwa ntchito mwapadera, monga zokutira kapena zikopa zopangidwa. Machitidwe oyambitsa nthawi zambiri amadalira ma redox awiriawiri, omwe amagwira ntchito kutentha kotsika. Emulsion polymerization imalola kuwongolera bwino kwambiri makhalidwe a tinthu, monga mawonekedwe ndi porosity, ngakhale kuti imaphatikizapo njira zovuta kwambiri zobwezeretsa zinthu pansi.
Ukadaulo wamakono wa PVC polymerization nthawi zambiri umaphatikiza zida zowunikira zomwe zili pamalopo, monga zowunikira kukula kwa tinthu tating'onoting'ono kapena mita yocheperako (monga momwe Lonnmeter imapangira), mu ndondomekoyi. Zida izi zimapereka ndemanga nthawi yeniyeni, zomwe zimathandiza kusintha kosalekeza liwiro la kugwedezeka, kutentha, ndi chakudya cha oyambitsa, motero kumawonjezera kusinthasintha kwa zinthu ndikuchepetsa zinyalala.
Magawo Abwino a VCM Opangira PVC Moyenera
Kuchita bwino ndi khalidwe la kupanga PVC zimagwirizana kwambiri ndi mphamvu zakuthupi ndi zamakemikolo za VCM. VCM yoyera kwambiri ndi yofunika kwambiri kuti polymerization ipambane komanso kuti polima igwire bwino ntchito.
Zodetsa zomwe zimapezeka mu VCM—monga madzi otsala, acetylene, organics chlorinated, kapena metal ions—zikhoza kupha tizilombo toyambitsa matenda, kuchepetsa kuchuluka kwa polymerization, ndikuyambitsa zolakwika mu PVC resin. Mwachitsanzo, kukhalapo kwa ma hydrocarbons ochepa a chlorinated, ngakhale m'magawo ang'onoang'ono pa miliyoni imodzi, kungasinthe kayendedwe ka zomwe zimachitika kapena kubweretsa mankhwala osakhala ndi mtundu. Njira zoyeretsera vinyl chloride monomer zogwira ntchito zimagwiritsidwa ntchito pamwamba, pogwiritsa ntchito njira monga multi-stage distillation (yomwe imagwiritsidwa ntchito m'malo odzipangira okha a VCM distillation) kuti achepetse zodetsa kufika pamlingo woyenera.
Kapangidwe ka thupi—makamaka kuchuluka kwa VCM ndi kuwongolera kwake—kamachita gawo lachindunji pakugwira ntchito ndi kubwerezabwereza kwa njira. Kuchuluka kwa madzi a VCM kumasiyana kwambiri ndi kutentha, zomwe zimakhudza kulondola kwa dosing, khalidwe la gawo panthawi ya polymerization, ndi magwiridwe antchito a agitation. Mwachitsanzo, pa 0°C, kuchuluka kwa VCM kuli pafupifupi 1.140 g/cm³, kutsika ndi kutentha kumawonjezeka. Kuwunika kodalirika komanso nthawi yeniyeni kwa kuchuluka kwa madzi a VCM (pogwiritsa ntchito inline density meters ngati omwe akuchokera ku Lonnmeter) kumatsimikizira kuti pali ma feed ratios oyenera, kumathandiza kuwerengera kutentha molondola, komanso kuthandizira kufanana kwa zinthu zomwe zimagwiritsidwa ntchito ndi batch-to-batch.
Zotsalira zodetsa, makamaka VCM yosayatsidwa, zimatha kuwononga chitetezo ndi ubwino wa chinthucho. Kuchuluka kwa VCM yaulere mu PVC yomalizidwa kumabweretsa zoopsa za poizoni ndipo kungakhudze zinthu monga kufooka, mphamvu ya makina, ndi kukhazikika kwa utoto. Malamulo nthawi zambiri amalamula kuti pakhale njira zochotsera zinthu zonse komanso kuyang'anira mosalekeza VCM nthawi yonse yopanga kuti zitsimikizire kuti zinthuzo zikuyenda bwino komanso mogwirizana ndi malamulo.
Zotsatira za khalidwe la VCM pa PVC zafotokozedwa bwino mu tchati chotsatirachi:
| Khalidwe Labwino la VCM | Zotsatira pa Njira ndi Zinthu za PVC |
| Chiyero (mankhwala opangidwa) | Zimakhudza mwachindunji kuchuluka kwa polymerization, kugawa kwa kulemera kwa mamolekyulu, mtundu, ndi kukhazikika kwa kutentha |
| Mkhalidwe wa thupi (kuchuluka kwa madzi) | Zimakhudza kulondola kwa mlingo, kusakaniza bwino, ndi mawonekedwe a polima |
| Zinthu zodetsedwa | Zimayambitsa kuzimitsa kwa oyambitsa, kuletsa kuchitapo kanthu, komanso kusagwira bwino ntchito kwa makina/kumapeto |
| Zotsalira (monga madzi, zachilengedwe) | Zingayambitse zolakwika za porosity, mawonekedwe a tinthu tosafanana, komanso mavuto ogwirira ntchito pansi pa madzi |
Kuonetsetsa kuti VCM ikuwongolera bwino kwambiri kudzera mu kuyeretsa kwapamwamba, kusungirako bwino, komanso ukadaulo woyezera kuchuluka kwa zinthu nthawi yeniyeni ndikofunikira kwambiri pakupanga bwino chomera cha vinyl chloride monomer komanso kukwaniritsa njira zodzitetezera zofunika muukadaulo wamakono wa vinyl chloride monomer.
Mafunso Ofunsidwa Kawirikawiri
Kodi njira ya vinyl chloride monomer ndi yotani?
Njira yopangira vinyl chloride monomer ndi njira yosinthira ethylene kukhala vinyl chloride monomer (VCM), yomwe ndi chakudya chofunikira kwambiri popanga utomoni wa PVC. Imayamba ndi chlorination ya ethylene, ndikupanga ethylene dichloride (EDC), nthawi zambiri kudzera mu chlorination yolunjika kapena oxychlorination. Kenako, EDC yoyera kwambiri imasweka mu uvuni pa 480–520°C, zomwe zimapangitsa kuti VCM ndi hydrogen chloride (HCl). Pansi pake, ma distillation towers angapo amayeretsa VCM, kuchotsa zinyalala ndi madzi kuti apereke chiyero cha >99.9% chofunikira pa polymerization. Kuvuta ndi kapangidwe ka chithunzi cha mayendedwe a vinyl chloride monomer zimadalira kapangidwe ka zomera, zolinga zogwira ntchito, komanso kuphatikiza zinyalala.
Kodi chomera cha vinyl chloride monomer chimaonetsetsa bwanji kuti chitetezo ndi kutsata malamulo okhudza chilengedwe?
Popeza VCM imatha kuyaka, imayambitsa khansa, komanso imakhala ndi zoopsa zachilengedwe, kapangidwe ka chomera cha vinyl chloride monomer kamayang'anira kuletsa ndi kuchepetsa. Malo opangira zinthu amagwiritsa ntchito njira zowongolera mpweya wambiri kuti ateteze nthunzi za organochlorine. Machitidwe odziwira kutayikira kwa madzi okha ndi njira zotsekera njira zimaletsa kutulutsa kwadzidzidzi. Malo ofunikira amagwiritsa ntchito zisindikizo zotseka mpweya ndi mayunitsi odzitetezera ku mpweya. HCl yopangidwa ndi HCl imabwezeretsedwanso kapena kuchiritsidwa kuti ichepetse kutuluka kwa madzi. Kuzimitsa EDC ikasweka kumaletsa kupangika kwa dioxin. Kutsatira malamulo kumatsimikiziridwa kudzera mu kuyang'anira nthawi yeniyeni komanso kutsatira malamulo okhudza mpweya ndi madzi.
Kodi vinyl chloride yamadzimadzi ndi chiyani, ndipo chifukwa chiyani kuchuluka kwake ndikofunikira?
Madzi a vinyl chloride ndi mtundu wa VCM wokhuthala komanso wopanikizika—wosungidwa ndikunyamulidwa pa kutentha kochepa kapena kuthamanga kwambiri kuti asatenthe. Kuchuluka kwa madzi a vinyl chloride, nthawi zambiri kumakhala pakati pa 0.910 ndi 0.970 g/cm³ kutengera kutentha ndi kuthamanga, ndi gawo lofunikira kwambiri popanga zombo zosungiramo zinthu, matanki oyenda mumsewu, ndi mizere yosamutsira. Deta yamadzi ya VCM ndiyofunikanso pakutsata zinthu, kusakaniza ntchito, kuwerengera bwino kuchuluka kwa zinthu, komanso kutsimikizira kuchuluka kwa ntchito zomwe zachitika pa ntchito yonse yopanga. Mamita ochulukirachulukira, monga omwe amapangidwa ndi Lonnmeter, amapereka kuwunika kosalekeza kofunikira kuti chitetezo cha ntchito chigwire bwino ntchito komanso kugwira ntchito bwino.
Nchifukwa chiyani nsanja yoyeretsera ndi yofunika kwambiri pa njira yoyeretsera ya VCM?
Nsanja zoyeretsera ndi zofunika kwambiri pa njira yoyeretsera vinyl chloride monomer. Zimalekanitsa VCM ndi EDC yotsalira, zonyansa zophikidwa pang'ono za chlorine, ndi "zolemera" zomwe zimapangidwa panthawi yopanga. Kugwira ntchito bwino kwa nsanja yoyeretsera ya VCM kumatsimikizira kuti monomer yodyetsera polymerization ikukwaniritsa miyezo yokhwima. Kuipitsidwa kulikonse, monga mankhwala osakhuta kapena chinyezi, kumatha kulepheretsa njira zoyeretsera PVC polymerization, kuyambitsa utomoni wosasankhidwa, kapena kuwononga ma catalyst otsika. Njira zapamwamba zoyeretsera VCM zimagwiritsa ntchito zokonzanso zambiri ndi ma tray apadera kuti ziwongolere kulekanitsa, kubwezeretsa zinthu zina, ndikuchepetsa kuipitsidwa kwa reboiler.
Kodi njira yopangira polymerization ya PVC ikugwirizana bwanji ndi kupanga vinyl chloride monomer?
Kuyera ndi kukhazikika kwa VCM ndizofunikira kwambiri pa ma resini apamwamba a polyvinyl chloride. Njira yopangira polymerization ya PVC imagwiritsa ntchito mwachindunji VCM mu ma reactors a polymerization (nthawi zambiri kudzera mu suspension, emulsion, kapena bulk technology). Kuwongolera molondola kapangidwe ka VCM kumakhudza kapangidwe ka mamolekyulu, ma profiles odetsedwa, ndi mawonekedwe enieni a zinthu zomaliza za PVC. Kugwirizana kwapafupi pakati pa njira yopangira vinyl chloride monomer ndi ukadaulo wa polymerization wa PVC kumatanthauza kuti kusinthasintha kulikonse kwa njira mu VCM—monga kusinthasintha kwa kachulukidwe, kuipitsidwa pang'ono, kapena kutentha—kungathe kufalikira mpaka gawo la polymerization, zomwe zimakhudza magwiridwe antchito ndi magwiridwe antchito azinthu.
Nthawi yotumizira: Disembala-18-2025
