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xov xwm

Furfural tshuaj sib txuas

Lub cev plaub hau (C4H3O-CHO), tseem hu ua 2-furaldehyde, tus tswv cuab paub zoo tshaj plaws ntawm tsev neeg ntawm furan thiab qhov chaw ntawm lwm cov xov paj tseem ceeb uas muaj txiaj ntsig. Nws yog cov kua tsis muaj kob (kub taw tes 161.7 ° C; lub ntiajteb txawj nqus 1.1598) raug rau tsaus ntuj rau ntawm huab cua. Nws dissolves hauv dej mus txog 8.3 feem pua ​​ntawm 20 ° C thiab yog miscible tag nrog dej cawv thiab ether.

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 Lub sijhawm ntev txog 100 xyoo tau cim lub sijhawm los ntawm kev tshawb pom ntawm furfural nyob rau hauv chav kuaj mus rau thawj qhov kev lag luam tsim khoom hauv xyoo 1922. Kev tsim kho tom ntej kev lag luam muab ib qho piv txwv zoo ntawm kev siv khoom siv ntawm kev ua qoob loo. Cov pob kws, oat hulls, cottonseed hulls, nplej hulls, thiab bagasse yog qhov khoom siv raw khoom loj, qhov kev hloov kho txhua xyoo uas ua kom tau txais khoom mus txuas ntxiv. Hauv cov txheej txheem tsim khoom siv, ntau ntawm cov khoom siv raw thiab dilute sulfuric acid yog steamed nyob rau hauv siab nyob rau hauv cov zom loj loj. Cov furfural tsim tau muab tshem tawm tas li nrog lub zog khov kho, thiab muaj zog los ntawm distillation; lub distillate, ntawm hws, cais ua ob txheej. Cov txheej hauv qab, suav nrog ntub furfural, yog ziab los ntawm lub qhov nqus dej kom tau txais furfural tsawg kawg 99 feem pua ​​purity.

Furfural yog siv los ua cov tshuaj pleev xim rau cov roj nplua nyeem thiab cov rosin, thiab txhawm rau txhim kho cov yam ntxwv ntawm roj roj thiab catalytic cracker rov qab cov khoom lag luam. Nws ua haujlwm ntau hauv kev tsim cov khoom siv roj-sib raug zoo muaj log thiab rau kev ua kom huv ntawm butadiene xav tau kev tsim cov roj hmab hluavtaws. Kev tsim cov nylon yuav tsum tau hexamethylenediamine, ntawm uas furfural yog qhov tseem ceeb. Qhov mob hws nrog phenol muab cov nplaim tawv furfural-phenolic rau ntau txoj kev siv.

Thaum vapors ntawm furfural thiab hydrogen dhau hla tooj liab catalyst ntawm kev kub, furfuryl cawv tsim. Qhov tseem ceeb no yog siv nyob rau hauv kev lag luam tshuab kev lag luam kev lag luam uas tiv thaiv xeb thiab cam-puab khoom. Qhov zoo sib xws hydrogenation ntawm furfuryl cawv dhau ib npib tsib xee catalyst muab tetrahydrofurfuryl cawv, los ntawm cov uas tau muab ntau yam esters thiab dihydropyran.

 Nyob rau hauv nws cov tshuaj tiv thaiv raws li aldehyde, furfural bears ib tug muaj zog zoo ib yam li benzaldehyde. Yog li, nws undergoes Cannizzaro cov tshuaj tiv thaiv hauv muaj zog aqueous alkali; nws dimerizes rau furoin, C4H3OCO-CHOH-C4H3O, qaug dej caw ntawm potassium cyanide; nws hloov dua siab tshiab rau hydrofuramide, (C4H3O-CH)3N2, los ntawm kev ua ntawm ammonia. Txawm li cas los xij, furfural txawv cim ntawm benzaldehyde nyob rau ntau txoj hau kev, ntawm uas autoxidation yuav pab ua piv txwv. Ntawm kev tshaj tawm ntawm huab cua hauv chav tsev kub, furfural yog degraded thiab cleaved rau cov kua qaub thiab cov kua qaub formylacrylic. Furoic acid yog dawb crystalline khoom siv tau zoo raws li cov tshuaj tua kab mob thiab ua kom lub zog ntev. Nws cov esters yog cov kua ntxhiab tsw qab los siv ua cov khoom xyaw hauv cov tshuaj tsw qab thiab tsw.


Lub sij hawm tshaj tawm: Lub Yim Hli-15-2020