Methyl methacrylate (MMA) ne mai muhimmanci Organic sinadaran albarkatun kasa da kuma polymer monomer, yafi amfani a samar da Organic gilashin, gyare-gyaren robobi, acrylics, coatings da Pharmaceutical polymer kayan, da dai sauransu Yana da wani high-karshen abu ga Aerospace, lantarki bayanai, Tantancewar fiber, robotics da sauran filayen.

A matsayin abu monomer, MMA yafi amfani a samar da polymethyl methacrylate (wanda aka fi sani da plexiglass, PMMA), kuma za a iya copolymerized tare da sauran vinyl mahadi don samun samfurori tare da daban-daban kaddarorin, kamar ga yi na polyvinyl chloride (PVC) Additives ACR, MBS kuma a matsayin na biyu monomer a samar da acrylic.

A halin yanzu, akwai nau'i uku na balagagge matakai don samar da MMA a gida da kuma kasashen waje: methacrylamide hydrolysis esterification hanya (acetone cyanohydrin Hanyar da methacrylonitrile Hanyar), isobutylene hadawan abu da iskar shaka hanya (Mitsubishi tsari da Asahi Kasei tsari) da ethylene carbonyl kira hanya (BASF Hanyar da Lucite Alpha hanya).

1. Methacrylamide hydrolysis esterification hanya
Wannan hanya ita ce hanyar samar da MMA na gargajiya, gami da hanyar acetone cyanohydrin da hanyar methacrylonitrile, duka bayan methacrylamide matsakaici hydrolysis, esterification kira na MMA.

(1) Hanyar cyanohydrin acetone (hanyar ACH)

Hanyar ACH, wacce Amurka Lucite ta fara haɓaka, ita ce farkon hanyar samar da masana'antu ta MMA, kuma ita ce babban tsarin samar da MMA a duniya a halin yanzu. Wannan hanyar tana amfani da acetone, hydrocyanic acid, sulfuric acid da methanol azaman albarkatun ƙasa, kuma matakan amsa sun haɗa da: amsawar cyanohydrinization, amsawar amidation da halayen esterification na hydrolysis.

Tsarin ACH ya balaga da fasaha, amma yana da babban lahani masu zuwa:

○ Yin amfani da acid hydrocyanic mai guba mai guba, wanda ke buƙatar tsauraran matakan kariya yayin ajiya, sufuri da amfani;

○ Ta hanyar samar da adadin acid mai yawa (maganin ruwa mai ruwa tare da sulfuric acid da ammonium bisulfate a matsayin manyan abubuwan da ke dauke da ƙananan kwayoyin halitta), adadin wanda shine 2.5 ~ 3.5 sau na MMA, kuma shine babban tushen gurbataccen muhalli;

o Sakamakon amfani da sulfuric acid, ana buƙatar kayan aikin kariya, kuma aikin na'urar yana da tsada.

(2) Hanyar Methacrylonitrile (Hanyar MAN)

Asahi Kasei ya haɓaka tsarin methacrylonitrile (MAN) bisa hanyar ACH, watau, isobutylene ko tert-butanol yana oxidized ta ammonia don samun MAN, wanda ke amsawa da sulfuric acid don samar da methacrylamide, wanda ya amsa tare da sulfuric acid da methanol don samar da MMA. Hanyar MAN ta hada da ammonia oxidation reaction, amidation reaction da hydrolysis esterification dauki, kuma zai iya amfani da mafi yawan kayan aiki na ACH shuka. Halin hydrolysis yana amfani da sulfuric acid da yawa, kuma yawan amfanin matsakaicin methacrylamide ya kusan 100%. Koyaya, hanyar tana da samfuran hydrocyanic acid mai guba mai guba, hydrocyanic acid da sulfuric acid suna da lalacewa sosai, abubuwan da ake buƙata na kayan aiki suna da girma sosai, yayin da haɗarin muhalli suna da yawa.

2. isobutylene hadawan abu da iskar shaka hanya
Isobutylene oxidation ya kasance hanyar fasaha da aka fi so ga manyan kamfanoni a duniya saboda yawan ingancinsa da kare muhalli, amma matakin fasaha yana da girma, kuma Japan ce kawai ta taba samun fasahar a duniya kuma ta toshe fasahar zuwa China. Hanyar ta ƙunshi nau'ikan tsarin Mitsubishi guda biyu da tsarin Asahi Kasei.

(1) Tsarin Mitsubishi (hanyar isobutylene uku)

Mitsubishi Rayon na Japan ya haɓaka wani sabon tsari don samar da MMA daga isobutylene ko tert-butanol a matsayin albarkatun ƙasa, zaɓin oxidation mataki biyu ta iska don samun methacrylic acid (MAA), sa'an nan kuma an ƙera shi da methanol. Bayan haɓaka masana'antu na Mitsubishi Rayon, Kamfanin Japan Asahi Kasei, Japan Kyoto Monomer Company, Korea Lucky Company, da dai sauransu sun fahimci masana'antu daya bayan daya. A cikin gida Shanghai Huayi Group Company zuba jari mai yawa dan Adam da kuma kudi albarkatun, da kuma bayan shekaru 15 na ci gaba da kuma unremitting kokarin na al'ummomi biyu, ya samu nasarar ɓullo da kansa biyu-mataki hadawan abu da iskar shaka da esterification na isobutylene tsabta samar MMA fasahar, da kuma a cikin Disamba 2017, shi kammala da kuma sanya a cikin aiki a 50,000-ton MMA masana'antu kamfanin, Donanggdoming Huang Hui, a cikin hadin gwiwa. Lardi, karya ikon mallakar fasaha na Japan tare da zama kamfani daya tilo da ke da wannan fasaha a kasar Sin. fasahar, kuma ta sanya kasar Sin kasa ta biyu da ke da fasahar masana'antu don samar da MAA da MMA ta hanyar iskar oxygen na isobutylene.

(2) Tsarin Asahi Kasei (tsari mai mataki biyu isobutylene)

Kamfanin Asahi Kasei na Japan ya dade yana jajircewa wajen samar da hanyar tantancewa kai tsaye don samar da MMA, wanda aka samu nasarar kerawa kuma aka fara aiki a shekarar 1999 tare da masana'antar masana'antu mai nauyin ton 60,000 a Kawasaki na kasar Japan, daga baya kuma ya fadada zuwa ton 100,000. Hanyar fasaha ta ƙunshi amsawar mataki biyu, watau oxidation na isobutylene ko tert-butanol a cikin lokaci na iskar gas a ƙarƙashin aikin Mo-Bi composite oxide catalyst don samar da methacrolein (MAL), wanda ke biye da oxidative esterification na MAL a cikin ruwa lokaci a ƙarƙashin aikin Pd-Pb mai kara kuzari don samar da hanyar MMA kai tsaye. MMA. Hanyar tsari na Asahi Kasei yana da sauƙi, tare da matakai biyu kawai na amsawa da ruwa kawai a matsayin samfurin samfurin, wanda yake da kore da kuma yanayin muhalli, amma zane da shirye-shiryen mai kara kuzari yana da matukar bukata. An ba da rahoton cewa an inganta aikin asahi Kasei oxidative esterification catalyst daga ƙarni na farko na Pd-Pb zuwa sabon ƙarni na Au-Ni catalyst.

Bayan da aka bunkasa fasahar Asahi Kasei daga shekarar 2003 zuwa 2008, cibiyoyin bincike na cikin gida sun fara samun bunkasuwar bincike a wannan fanni, tare da bangarori da dama kamar jami'ar Hebei Normal University, Institute of Process Engineering, Academy of Sciences na kasar Sin, Jami'ar Tianjin da Jami'ar Injiniya Harbin sun mai da hankali kan ci gaba da inganta fasahar Pd-Pb, da dai sauransu. wanda shi ne Dalian Institute of Chemical Engineering, kasar Sin Academy of Sciences, ya samu babban ci gaba a cikin kananan gwajin gwajin, kammala inganta nano-zinariya kara kuzari tsarin shiryawa, dauki halin da ake ciki gwajin da kuma a tsaye inganci da dogon zagayowar aiki da gwajin, kuma a yanzu rayayye hada kai da kamfanoni don bunkasa fasahar masana'antu.

3. Ethylene carbonyl kira hanya
Fasahar ethylene carbonyl kirar hanyar masana'antu ta haɗa da tsarin BASF da tsarin ethylene-propionic acid methyl ester.

(1) Hanyar ethylene-propionic acid (tsarin BASF)

Tsarin ya ƙunshi matakai guda huɗu: an cire ethylene hydroformylated don samun propionaldehyde, propionaldehyde yana danne tare da formaldehyde don samar da MAL, MAL yana da iskar oxidized a cikin madaidaicin gadon gado don samar da MAA, kuma MAA ya rabu kuma an tsarkake shi don samar da MMA ta hanyar esterification tare da methanol. Halin shine maɓalli mataki. Tsarin yana buƙatar matakai huɗu, wanda yake da ɗanɗano kaɗan kuma yana buƙatar kayan aiki masu yawa da tsadar saka hannun jari, yayin da fa'ida ita ce ƙarancin farashin albarkatun ƙasa.

Hakanan an sami ci gaban cikin gida a cikin haɓaka fasahar ethylene-propylene-formaldehyde na MMA. 2017, Shanghai Huayi Group Company, tare da haɗin gwiwar Nanjing NOAO New Materials Company da Tianjin University, kammala wani matukin jirgi na 1,000 ton na propylene-formaldehyde condensation tare da formaldehyde zuwa methacrolein da kuma ci gaban wani tsari kunshin na 90,000-ton masana'antu shuka. Bugu da kari, Cibiyar Injiniya Tsari ta Kwalejin Kimiyya ta kasar Sin, tare da hadin gwiwar kungiyar Henan Energy da Chemical Group, sun kammala aikin gwajin gwajin masana'antu mai nauyin ton 1,000, tare da samun nasarar samun kwanciyar hankali a shekarar 2018.

(2) Tsarin Ethylene-methyl propionate (tsarin Lucite Alpha)

Lucite Alpha tsarin aiki yanayi ne m, samfurin da ake samu ne high, shuka zuba jari da kuma albarkatun kasa farashin ne low, da kuma sikelin na guda naúrar ne mai sauki yi babban, a halin yanzu kawai Lucite yana da keɓantaccen iko na wannan fasaha a duniya kuma ba a canjawa wuri zuwa waje duniya.

An rarraba tsarin Alpha zuwa matakai biyu:

Mataki na farko shine amsawar ethylene tare da CO da methanol don samar da methyl propionate

ta yin amfani da palladium-based homogeneous carbonylation mai kara kuzari, wanda yana da halaye na babban aiki, babban zaɓi (99.9%) da kuma tsawon rayuwar sabis, kuma ana aiwatar da martani a ƙarƙashin yanayi mai laushi, wanda ba shi da lahani ga na'urar kuma yana rage saka hannun jari na babban gini;

Mataki na biyu shine amsawar methyl propionate tare da formaldehyde don samar da MMA

Ana amfani da mai kara kuzari mai yawa, wanda ke da babban zaɓi na MMA. A cikin 'yan shekarun nan, kamfanoni na cikin gida sun ba da babbar sha'awa ga ci gaban fasaha na methyl propionate da formaldehyde condensation zuwa MMA, kuma sun sami babban ci gaba a cikin haɓakar haɓakawa da haɓaka tsarin amsawa ga gado, amma rayuwa mai haɓakawa ba ta kai ga buƙatun aikace-aikacen masana'antu ba.