Vinyl acetate (Vac), wanda kuma aka sani da vinyl acetate ko vinyl acetate, ruwa ne marar launi mara launi a yanayin zafi da matsa lamba, tare da tsarin kwayoyin C4H6O2 da nauyin kwayoyin dangi na 86.9.Vac, a matsayin ɗaya daga cikin kayan albarkatun masana'antu da aka fi amfani da su a duniya, na iya samar da abubuwan da suka samo asali kamar polyvinyl acetate resin (PVAc), polyvinyl barasa (PVA), da polyacrylonitrile (PAN) ta hanyar polymerization na kai ko copolymerization tare da wasu monomers.Ana amfani da waɗannan abubuwan haɓaka sosai a cikin gine-gine, masaku, injina, magunguna, da inganta ƙasa.Saboda saurin ci gaban masana'antar tashar jiragen ruwa a cikin 'yan shekarun nan, samar da acetate na vinyl ya nuna haɓakar haɓakawa kowace shekara, tare da jimlar samar da acetate na vinyl ya kai 1970kt a cikin 2018. A halin yanzu, saboda tasirin albarkatun ƙasa da kuma abubuwan da suka faru. matakai, hanyoyin samar da acetate na vinyl sun hada da hanyar acetylene da hanyar ethylene.
1. Acetylene tsari
A cikin 1912, F. Klatte, ɗan Kanada, ya fara gano vinyl acetate ta amfani da wuce haddi na acetylene da acetic acid a ƙarƙashin matsin yanayi, a yanayin zafi daga 60 zuwa 100 ℃, kuma yana amfani da salts na mercury a matsayin mai kara kuzari.A cikin 1921, Kamfanin CEI na Jamus ya ƙirƙira wata fasaha don haɓaka lokacin tururi na vinyl acetate daga acetylene da acetic acid.Tun daga wannan lokacin, masu bincike daga kasashe daban-daban sun ci gaba da inganta tsari da yanayin da ake kira vinyl acetate daga acetylene.A cikin 1928, Kamfanin Hoechst na Jamus ya kafa 12 kt/a vinyl acetate samar naúrar, fahimtar masana'antu babban sikelin samar da vinyl acetate.Matsakaicin samar da vinyl acetate ta hanyar acetylene shine kamar haka:
Babban martani:

Tasirin illa:

Hanyar acetylene ta kasu kashi-kashi hanyar ruwa lokaci da hanyar iskar gas.
Halin lokaci mai amsawa na hanyar acetylene ruwa lokaci shine ruwa, kuma reactor shine tankin dauki tare da na'urar motsa jiki.Saboda gazawar hanyar lokaci na ruwa kamar ƙarancin zaɓin zaɓi da samfuran samfuri da yawa, an maye gurbin wannan hanyar da hanyar lokacin gas na acetylene a halin yanzu.
Dangane da mabambantan tushen shirye-shiryen gas na acetylene, hanyar acetylene gas lokaci za a iya raba zuwa hanyar iskar gas acetylene Borden da hanyar carbide acetylene Wacker.
Tsarin Borden yana amfani da acetic acid azaman adsorbent, wanda ke haɓaka ƙimar amfani da acetylene sosai.Koyaya, wannan hanyar hanya tana da wahala ta fasaha kuma tana buƙatar farashi mai yawa, don haka wannan hanyar tana da fa'ida a cikin wuraren da ke da albarkatun iskar gas.
Tsarin Wacker yana amfani da acetylene da acetic acid da aka samar daga calcium carbide azaman albarkatun ƙasa, ta amfani da mai kara kuzari tare da carbon da aka kunna azaman mai ɗaukar hoto da zinc acetate azaman kayan aiki, don haɗa Vac ƙarƙashin matsin yanayi da zafin jiki na 170 ~ 230 ℃.Fasahar tsari yana da sauƙi mai sauƙi kuma yana da ƙananan farashin samarwa, amma akwai kasawa irin su asarar sauƙi na kayan aiki masu tasiri, rashin kwanciyar hankali, yawan amfani da makamashi, da kuma gurɓataccen abu.
2. Ethylene tsari
Ethylene, oxygen, da glacial acetic acid su ne albarkatun kasa guda uku da aka yi amfani da su a cikin tsarin ethylene na tsarin vinyl acetate.Babban abin aiki na mai kara kuzari shine yawanci rukuni na takwas mai daraja na ƙarfe, wanda aka mayar da martani a wani yanayin zafi da matsa lamba.Bayan aiki na gaba, samfurin vinyl acetate da aka yi niyya an samu ƙarshe.Ma'aunin martani shine kamar haka:
Babban martani:

Tasirin illa:

Kamfanin Bayer ne ya fara samar da tsarin tururi na ethylene kuma an saka shi cikin samar da masana'antu don samar da vinyl acetate a cikin 1968. An kafa layin samarwa a Hearst da Bayer Corporation a Jamus da National Distillers Corporation a Amurka, bi da bi.Mafi yawa palladium ko zinariya ɗora Kwatancen a kan acid resistant goyon baya, kamar silica gel beads tare da radius na 4-5mm, da ƙari na wani adadin potassium acetate, wanda zai iya inganta aiki da selectivity na mai kara kuzari.Tsarin da ake kira vinyl acetate ta amfani da ethylene tururi lokaci na USI hanya yayi kama da hanyar Bayer, kuma ya kasu kashi biyu: kira da distillation.Tsarin USI ya sami aikace-aikacen masana'antu a cikin 1969. Abubuwan da ke aiki na mai haɓakawa sune galibi palladium da platinum, kuma wakili mai taimako shine potassium acetate, wanda ke goyan bayan mai ɗaukar alumina.Yanayin amsawa yana da ɗan sauƙi kuma mai haɓakawa yana da tsawon rayuwar sabis, amma yawan amfanin sararin samaniya yana da ƙasa.Idan aka kwatanta da hanyar acetylene, hanyar tsarin tururi na ethylene ya inganta sosai a cikin fasaha, kuma abubuwan da aka yi amfani da su a cikin hanyar ethylene sun ci gaba da inganta aiki da zaɓi.Koyaya, har yanzu ana buƙatar bincikar motsin motsin motsi da tsarin kashewa.
Samar da acetate na vinyl ta hanyar amfani da hanyar ethylene yana amfani da ma'aunin gyaran gado na tubular da ke cike da mai kara kuzari.Gas ɗin ciyarwa yana shiga cikin reactor daga sama, kuma lokacin da ya tuntuɓar gado mai ƙara kuzari, halayen catalytic suna faruwa don samar da samfurin vinyl acetate da aka yi niyya da ƙaramin adadin carbon dioxide.Saboda yanayin halayen halayen, ana shigar da ruwa mai matsa lamba a cikin gefen harsashi na reactor don cire zafin amsa ta hanyar amfani da vaporization na ruwa.
Idan aka kwatanta da hanyar acetylene, hanyar ethylene tana da halaye na ƙayyadaddun tsarin na'ura, babban fitarwa, ƙarancin amfani da makamashi, da ƙarancin gurɓataccen gurɓataccen abu, kuma farashin samfurin ya yi ƙasa da na hanyar acetylene.Ingancin samfurin ya fi girma, kuma yanayin lalata ba shi da mahimmanci.Saboda haka, hanyar ethylene a hankali ta maye gurbin hanyar acetylene bayan 1970s.Dangane da kididdigar da ba ta cika ba, kusan kashi 70% na Vac da aka samar ta hanyar ethylene a duniya ya zama babban tushen hanyoyin samar da Vac.
A halin yanzu, fasahar samar da Vac mafi ci gaba a duniya ita ce BP's Leap Process da Celanese's Vantage Process.Idan aka kwatanta da ƙayyadaddun tsarin iskar gas na zamani na ethylene na gargajiya, waɗannan fasahohin tsari guda biyu sun inganta haɓakar reactor da mai kara kuzari a jigon rukunin, inganta tattalin arziki da amincin aikin naúrar.
Celanese ta haɓaka sabon ƙayyadaddun tsari na Vantage na gado don magance matsalolin rashin daidaituwa na rarraba gado da ƙaramin ethylene jujjuyawar hanya ɗaya a cikin ingantattun injinan gado.Reactor da aka yi amfani da shi a cikin wannan tsari har yanzu shi ne ƙayyadaddun gado, amma an sami ci gaba mai mahimmanci ga tsarin mai kara kuzari, kuma an ƙara na'urorin dawo da ethylene a cikin iskar gas ɗin wutsiya, ta hanyar shawo kan gazawar tsarin gyaran gado na gargajiya.Yawan amfanin samfurin vinyl acetate yana da girma fiye da na na'urori masu kama da juna.Mai haɓaka tsarin yana amfani da platinum azaman babban kayan aiki, silica gel azaman mai ɗaukar hoto, sodium citrate azaman wakili mai ragewa, da sauran ƙarin karafa irin su lanthanide rare ƙasa abubuwa kamar praseodymium da neodymium.Idan aka kwatanta da masu kara kuzari na gargajiya, ana inganta zaɓin, aiki, da yawan lokacin sararin samaniya na mai kara kuzari.
BP Amoco ya haɓaka tsarin yanayin gas na ethylene na gado mai ruwa, wanda kuma aka sani da Tsarin Tsari, kuma ya gina rukunin gado na 250 kt/a na ruwa mai ruwa a Hull, Ingila.Yin amfani da wannan tsari don samar da acetate na vinyl zai iya rage farashin samarwa ta hanyar 30%, kuma yawan lokaci na sararin samaniya na mai kara kuzari (1858-2744 g / (L · h-1)) ya fi girma fiye da tsarin gyaran gado (700). -1200 g/(L · h-1)).
Tsarin LeapProcess yana amfani da reactor na gado mai ruwa a karon farko, wanda ke da fa'idodi masu zuwa idan aka kwatanta da ƙayyadadden reactor na gado:
1) A cikin na'urar reactor na gado mai ruwa, mai kara kuzari yana ci gaba da gaurayewa daidai gwargwado, don haka yana ba da gudummawa ga daidaitawar mai talla da kuma tabbatar da daidaitaccen taro na mai talla a cikin reactor.
2) The fluidized gado reactor iya ci gaba da maye gurbin da kashe mai kara kuzari da sabo kara kuzari a karkashin aiki yanayi.
3) The fluidized gado dauki zafin jiki ne akai, minimizing kara kuzari deactivation saboda gida overheating, game da shi mika rayuwar sabis na kara kuzari.
4) Hanyar kawar da zafi da ake amfani da ita a cikin injin gado na ruwa yana sauƙaƙa tsarin reactor kuma yana rage girmansa.A wasu kalmomi, ana iya amfani da ƙirar reactor guda ɗaya don manyan sinadarai masu yawa, wanda zai inganta sikelin ingancin na'urar.