I-Vinyl acetate (VAc), eyaziwa nangokuthi i-vinyl acetate noma i-vinyl acetate, iwuketshezi olungenambala obala olusezingeni lokushisa elivamile nokucindezela, olunefomula yamangqamuzana engu-C4H6O2 kanye nesisindo samangqamuzana esihlobene esingu-86.9.I-VAc, njengenye yezinto ezisetshenziswa kakhulu ezimbonini ezisetshenziswa kakhulu emhlabeni, ingakhiqiza okuphuma kuyo njenge-polyvinyl acetate resin (PVAc), i-polyvinyl alcohol (PVA), kanye ne-polyacrylonitrile (PAN) ngokuzenza i-polymerization noma i-copolymerization namanye ama-monomers.Lezi ziphuma zisetshenziswa kakhulu ekwakhiweni, kwendwangu, kwemishini, kwezokwelapha, nasekuthuthukisweni kwenhlabathi.Ngenxa yokuthuthukiswa okusheshayo kwemboni ye-terminal eminyakeni yamuva, ukukhiqizwa kwe-vinyl acetate kubonise umkhuba wokukhula unyaka nonyaka, nokukhiqizwa okuphelele kwe-vinyl acetate kufinyelela ku-1970kt ngo-2018. Njengamanje, ngenxa yethonya lezinto zokusetshenziswa kanye izinqubo, izindlela zokukhiqiza ze-vinyl acetate ikakhulukazi zihlanganisa indlela ye-acetylene kanye nendlela ye-ethylene.
1. Inqubo ye-acetylene
Ngo-1912, uF. Klatte, waseCanada, waqala ukuthola i-vinyl acetate esebenzisa i-acetylene ne-acetic acid eyeqile ngaphansi kwengcindezi yasemkhathini, emazingeni okushisa asukela ku-60 kuya ku-100 ℃, futhi esebenzisa usawoti we-mercury njengama-catalysts.Ngo-1921, Inkampani yaseJalimane i-CEI yathuthukisa ubuchwepheshe bokuhlanganiswa kwesigaba somphunga se-vinyl acetate kusuka ku-acetylene ne-acetic acid.Kusukela lapho, abacwaningi abavela emazweni ahlukahlukene baye bathuthukisa ngokuqhubekayo inqubo nezimo zokuhlanganiswa kwe-vinyl acetate kusuka ku-acetylene.Ngo-1928, i-Hoechst Company yaseJalimane yasungula iyunithi yokukhiqiza ye-vinyl acetate engu-12 kt/acetate, iqaphela ukukhiqizwa kwezimboni ezinkulu kwe-vinyl acetate.I-equation yokukhiqiza i-vinyl acetate ngendlela ye-acetylene imi kanje:
Ukusabela okuyinhloko:

Okuqhamuka uma udla imishanguzo:

Indlela ye-acetylene ihlukaniswe ngendlela yesigaba se-liquid kanye nendlela yesigaba segesi.
Isimo sesigaba esisabelayo sendlela yesigaba se-acetylene liquid siwuketshezi, futhi i-reactor iyithangi lokusabela elinedivayisi enyakazayo.Ngenxa yokushiyeka kwendlela yesigaba se-liquid njengokukhetha okuphansi kanye nemikhiqizo eminingi, le ndlela ithathelwe indawo indlela yesigaba segesi ye-acetylene njengamanje.
Ngokusho kwemithombo ehlukene yokulungiswa kwegesi ye-acetylene, indlela yesigaba segesi ye-acetylene ingahlukaniswa ngegesi yemvelo ye-acetylene Borden indlela kanye ne-carbide acetylene Wacker indlela.
Inqubo ye-Borden isebenzisa i-acetic acid njenge-adsorbent, ethuthukisa kakhulu izinga lokusetshenziswa kwe-acetylene.Kodwa-ke, lo mzila wenqubo unzima ngokobuchwepheshe futhi udinga izindleko eziphezulu, ngakho le ndlela ithatha inzuzo ezindaweni ezinothile ngemithombo yegesi yemvelo.
Inqubo ye-Wacker isebenzisa i-acetylene ne-acetic acid ekhiqizwe ku-calcium carbide njengezinto zokusetshenziswa, kusetshenziswa i-catalyst enekhabhoni ecushiwe njengesiphathi kanye ne-zinc acetate njengengxenye esebenzayo, ukuze kuhlanganiswe i-VAc ngaphansi kwengcindezi yomoya kanye nezinga lokushisa lokusabela elingu-170~230 ℃.Ubuchwepheshe benqubo bulula uma kuqhathaniswa futhi bunezindleko eziphansi zokukhiqiza, kodwa kukhona ukushiyeka njengokulahlekelwa kalula kwezingxenye ezisebenzayo ze-catalyst, ukuzinza okubi, ukusetshenziswa kwamandla okuphezulu, kanye nokungcola okukhulu.
2. Inqubo ye-ethylene
I-Ethylene, umoya-mpilo, ne-glacial acetic acid yizinto ezintathu zokusetshenziswa ezisetshenziswa ekuhlanganiseni kwe-ethylene yenqubo ye-vinyl acetate.Ingxenye eyinhloko esebenzayo ye-catalyst ngokuvamile i-elementi yensimbi ehloniphekile yeqembu lesishiyagalombili, esabela ezingeni elithile lokushisa nokucindezelwa.Ngemuva kokucubungula okulandelayo, umkhiqizo ohlosiwe we-vinyl acetate ekugcineni utholakala.I-reaction equation imi kanje:
Ukusabela okuyinhloko:

Okuqhamuka uma udla imishanguzo:

Inqubo yesigaba somhwamuko we-ethylene yasungulwa okokuqala yi-Bayer Corporation futhi yafakwa ekukhiqizweni kwezimboni ukuze kukhiqizwe i-vinyl acetate ngo-1968. Imigqa yokukhiqiza yasungulwa e-Hearst ne-Bayer Corporation eJalimane kanye ne-National Distillers Corporation e-United States, ngokulandelana.Ikakhulukazi i-palladium noma igolide elayishwe kuzisekelo ezimelana ne-asidi, njengobuhlalu bejeli ye-silica enobubanzi obungu-4-5mm, nokwengezwa kwenani elithile le-potassium acetate, elingathuthukisa umsebenzi nokukhetha kwe-catalyst.Inqubo yokuhlanganiswa kwe-vinyl acetate isebenzisa indlela ye-ethylene vapor yesigaba se-USI ifana nendlela ye-Bayer, futhi ihlukaniswe izingxenye ezimbili: i-synthesis kanye ne-distillation.Inqubo ye-USI yazuza ukusetshenziswa kwezimboni ngo-1969. Izingxenye ezisebenzayo ze-catalyst ngokuyinhloko i-palladium ne-platinum, futhi i-ejenti eyisizayo i-potassium acetate, esekelwa kusithwali se-alumina.Izimo zokusabela zithambile futhi i-catalyst inesevisi ende yokuphila, kodwa isivuno sesikhathi sesikhala siphansi.Uma kuqhathaniswa nendlela ye-acetylene, indlela yesigaba se-ethylene vapor ithuthuke kakhulu kwezobuchwepheshe, futhi ama-catalysts asetshenziswe endleleni ye-ethylene aye athuthuka ngokuqhubekayo emsebenzini nasekukhetheni.Kodwa-ke, i-reaction kinetics kanye nendlela yokuvala kusadingeka ihlolwe.
Ukukhiqizwa kwe-vinyl acetate kusetshenziswa indlela ye-ethylene isebenzisa i-reactor yombhede ongaguquki we-tubula egcwele i-catalyst.Igesi ephakelayo ingena kureactor isuka phezulu, futhi lapho ithinta umbhede we-catalyst, ukusabela okuvusa amadlingozi kwenzeka ukuze kukhiqizwe umkhiqizo oqondiwe we-vinyl acetate kanye nenani elincane le-carbon dioxide yomkhiqizo.Ngenxa yemvelo exakile yokusabela, amanzi acindezelwe angeniswa ohlangothini lwegobolondo le-reactor ukuze kususwe ukushisa okusabelayo ngokusebenzisa ukuhwamuka kwamanzi.
Uma kuqhathaniswa nendlela ye-acetylene, indlela ye-ethylene inezici zesakhiwo sedivayisi ehlangene, ukuphuma okukhulu, ukusetshenziswa kwamandla okuphansi, nokungcola okuphansi, futhi izindleko zayo zomkhiqizo ziphansi kunendlela ye-acetylene.Ikhwalithi yomkhiqizo iphakeme, futhi isimo sokugqwala asisibi kakhulu.Ngakho-ke, indlela ye-ethylene kancane kancane yashintsha indlela ye-acetylene ngemva kweminyaka yawo-1970.Ngokwezibalo ezingaphelele, cishe u-70% we-VAc okhiqizwa indlela ye-ethylene emhlabeni usuphenduke insakavukela yezindlela zokukhiqiza i-VAc.
Njengamanje, ubuchwepheshe bokukhiqiza be-VAc obuphambili kakhulu emhlabeni i-BP's Leap Process kanye ne-Vantage Process yaseCelanese.Uma kuqhathaniswa nenqubo yesigaba se-ethylene yesigaba segesi engaguquki, lobu buchwepheshe bezinqubo ezimbili buye benza ngcono kakhulu i-reactor kanye ne-catalyst emnyombeni weyunithi, ukuthuthukisa umnotho nokuphepha kokusebenza kweyunithi.
I-Celanese isungule inqubo entsha yombhede ongaguquki we-Vantage yokubhekana nezinkinga zokusatshalaliswa kombhede we-catalyst ongalingani kanye nokuguqulwa kwendlela eyodwa ye-ethylene ephansi kuma-reactor emibhede engaguquki.I-reactor esetshenziswe kule nqubo isengumbhede ongaguquki, kodwa ukuthuthukiswa okuphawulekayo kuye kwenziwa ohlelweni lwe-catalyst, futhi amadivaysi okubuyisela i-ethylene angeziwe kugesi lomsila, ukunqoba ukushiyeka kwezinqubo zendabuko zemibhede ehleliwe.Isivuno somkhiqizo we-vinyl acetate siphezulu kakhulu kunaleyo yamadivayisi afanayo.I-catalyst yenqubo isebenzisa i-platinum njengengxenye eyinhloko esebenzayo, ijeli ye-silica njenge-catalyst carrier, i-sodium citrate njenge-ejenti yokunciphisa, nezinye izinsimbi ezisizayo ezifana ne-lanthanide izakhi zomhlaba ezingavamile ezifana ne-praseodymium ne-neodymium.Uma kuqhathaniswa nama-catalysts endabuko, ukukhetha, umsebenzi, kanye nesivuno sesikhathi sesikhala se-catalyst kuyathuthukiswa.
I-BP Amoco isungule inqubo yesigaba segesi ye-ethylene yombhede, eyaziwa nangokuthi inqubo ye-Leap Process, futhi yakhe iyunithi yombhede ongu-250 kt/amanzi e-Hull, e-England.Ukusebenzisa le nqubo ukukhiqiza i-vinyl acetate kunganciphisa izindleko zokukhiqiza ngo-30%, futhi isivuno sesikhathi sesikhala se-catalyst (1858-2744 g/(L · h-1)) siphezulu kakhulu kunesohlelo lombhede ongaguquki (700). -1200 g/(L · h-1)).
Inqubo ye-LeapProcess isebenzisa i-reactor yombhede enoketshezi okokuqala ngqa, enezinzuzo ezilandelayo uma iqhathaniswa ne-reactor yombhede ongashintshi:
1) Ku-reactor yombhede omanzi, i-catalyst ixutshwa ngokuqhubekayo nangokufana, ngaleyo ndlela inikele ekusakazweni okufanayo komgqugquzeli nokuqinisekisa ukugxila okufanayo komgqugquzeli ku-reactor.
2) I-reactor yombhede ewuketshezi ingashintsha ngokuqhubekayo i-catalyst evaliwe nge-catalyst entsha ngaphansi kwezimo zokusebenza.
3) Izinga lokushisa lombhede omanzi lihlala njalo, linciphisa ukucisha i-catalyst ngenxa yokushisisa okweqile kwendawo, ngaleyo ndlela andise impilo yesevisi ye-catalyst.
4) Indlela yokususa ukushisa esetshenziswa ku-reactor yombhede omanzi yenza ukwakheka kwe-reactor ibe lula futhi inciphise umthamo wayo.Ngamanye amazwi, idizayini eyodwa yereactor ingasetshenziselwa ukufakwa kwamakhemikhali ngezinga elikhulu, ithuthukise kakhulu ukusebenza kwesikali kwedivayisi.