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izindaba

I-furfural chemical compound

Ubuningi (C4H3O-CHO), obizwa nangokuthi i-2-furaldehyde, ilungu elaziwa kakhulu lomndeni we-furan nomthombo wamanye ama-furan abalulekile kwezobuchwepheshe. Nguketshezi olungenambala (iphuzu elibilayo 161.7 ° C; amandla adonsela phansi 1.1598) kuncike ekubeni mnyama ekuvezeni emoyeni. Iyancibilika emanzini ize ifike kumaphesenti ayi-8.3 kuma-20 ° C futhi ayihambisani ngokuphelele notshwala ne-ether.

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 Isikhathi esiyiminyaka engaba yikhulu sabeka isikhathi esisukela ekutholakaleni kwezinwele elabhorethri kuya ekukhiqizweni kokuqala kokuhweba ngonyaka we-1922. Ukuthuthuka kwezimboni okwalandela kunikeza isibonelo esihle kakhulu sokusetshenziswa kwezinsalela zezolimo ezimbonini. Ama-corncobs, izigaxa ze-oat, izigaxa zekotini, izigaxa zelayisi, kanye ne-bagasse yimithombo emikhulu yempahla eluhlaza, ukugcwaliswa kwayo minyaka yonke okuqinisekisa ukuqhubeka kokutholakala. Enqubeni yokukhiqiza, inqwaba yempahla eluhlaza kanye ne-dilute acid sulfuric acid iyashiswa ngaphansi kwengcindezi kuma-digesters amakhulu ajikelezayo. Ukwakheka koboya kususwa ngokuqhubekayo ngomusi, futhi kugxilwe yi-distillation; i-distillate, ekufingqeni, yehlukanisa izigaba ezimbili. Ingqimba engezansi, equkethe ubumanzi obumanzi, iyomiswa nge-distillation ye-vacuum ukuthola ubumsulwa obuncane bama-99% wobumsulwa.

I-Furfural isetshenziswa njenge-solvent ekhethiwe yokuhluza uwoyela ne-rosin, nokwenza ngcono izici zikaphethiloli we-diesel kanye ne-catalytic cracker yokuphinda isetshenziswe esitokisini. Kusetshenziswa kakhulu ekwakhiweni kwamasondo abhidayo anenhlaka futhi kuhlanzwa ibutadiene edingekayo ekukhiqizeni injoloba yokwenziwa. Ukwenziwa kwenayiloni kudinga i-hexamethylenediamine, okuyi-furfural engumthombo obalulekile. Ukuhlangana ne-phenol kunikeza izinhlaka ze-furfural-phenolic zezindlela ezahlukahlukene zokusetshenziswa.

Lapho imiphunga ye-furfural ne-hydrogen idluliswa ngaphezulu kwesikhangisi sethusi emazingeni okushisa aphakeme, i-furfuryl alcohol iyakhiwa. Lesi sakhi esibalulekile sisetshenziswa embonini yeplastikhi ukukhiqizwa kosimende abangamelana nokugqwala nezinto ezibunjiweyo. I-hydrogenation efanayo ye-furfuryl alcohol ngaphezulu kwe-nickel catalyst inika i-tetrahydrofurfuryl utshwala, okususelwa kuyo ama-esters ahlukahlukene kanye ne-dihydropyran.

 Ekuziphenduleni kwayo njenge-aldehyde, i-furfural ifana ngokuqinile ne-benzaldehyde. Ngakho-ke, ibhekana nokusabela kweCannizzaro kuma-alkali aqueous aqinile; inciphisa i-furoin, uC4H3OCO-CHOH-C4H3O, ngaphansi kwethonya le-potassium cyanide; iguqulelwa ku-hydrofuramide, (C4H3O-CH)3N2, ngesenzo se-ammonia. Kodwa-ke, i-furfural yehluke kakhulu kwi-benzaldehyde ngezindlela eziningi, lapho i-autoxidation izosebenza njengesibonelo. Lapho kuvezwa umoya ekamelweni lokushisa, i-furfural yehlisiwe futhi yahlanganiswa ne-formic acid ne-formylacrylic acid. I-Furoic acid iyi-crystalline emhlophe eqinile ewusizo njenge-bactericide kanye ne-preservative. Ama-ester ayo anguketshezi olunephunga elimnandi olusetshenziswa njengezithako kumakha nokunambitheka.


Isikhathi Iposi: Aug-15-2020