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Pūhui kemika ʻo Furfural

ʻO Furfural (C4H3ʻO-CHO), i kapa ʻia hoʻi ʻo 2-furaldehyde, lālā kaulana loa o ka ʻohana furan a me ke kumu o nā furans koʻikoʻi ʻenehana ʻē aʻe. He wai kala ʻole ia (wahi paila 161.7 ° C; umekaumaha kikoʻī 1.1598) e pili ana i ka pouli ʻana i ke ea. Hoʻopau ia i loko o ka wai a hiki i ka nui o 8.3 pakeneka ma 20 ° C a miscible loa me ka wai ʻona a me ka ether.

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 ʻO kahi lōʻihi ma kahi o 100 mau makahiki i kahakaha ʻia ka wā mai ka loaʻa ʻana o furfural i loko o ke keʻena hoʻokolohua a hiki i ka hana kalepa mua ma 1922. ʻO ka hoʻomohala ʻenehana aʻe e hāʻawi ana i kahi hiʻohiʻona maikaʻi loa o ka ʻoihana hoʻohana o nā koena mahiʻai. ʻO Corncobs, nā oat hulls, nā pulupulu pulupulu, nā laiki laiki, a me nā bagasse nā kumuwaiwai waiwai nui, ka hoʻopiha makahiki e hōʻoia ana i ka hoʻomau ʻana o ka lako. I ke kaʻina hana, nā nui o nā mea maka a me ka dilute sulfuric acid e hoʻomoʻa ʻia ma lalo o ke kaomi i nā mea huli rotary nui. Lawe ʻia ka furfural i hana mau ʻia me ka mahu, a hoʻopili ʻia e ka distillation; ka distillate, ma ka condensation, hoʻokaʻawale i ʻelua papa. ʻO ka papa lalo, e komo ana i ka furfural pulu, ua hoʻomaloʻo ʻia e ka distillation vacuum e loaʻa ai ka furfural o ka liʻiliʻi 99 pakeneka.

Hoʻohana ʻia ʻo Furfural ma ke ʻano he koho hoʻoheheʻe no ka hoʻomaʻemaʻe ʻana i nā aila lubricating a me ka rosin, a me ka hoʻomaikaʻi ʻana i nā ʻano o ka wahie diesel a me nā waihona recycle catalytic cracker. Hoʻohana nui ʻia ia i ka hana ʻana i nā huila abrasive i hoʻopaʻa ʻia a resin a no ka hoʻomaʻemaʻe ʻana i ka butadiene e pono ai no ka hana o ka rubber synthetic. Pono ka hana o ka nylon i ka hexamethylenediamine, a ʻo kahi furfural kahi kumu waiwai. Hāʻawi ka condensation me phenol i nā resins furfural-phenolic no nā ʻano ʻano hoʻohana.

Ke hala ʻia nā mahu o ka furfural a me ka hydrogen ma luna o kahi mea hoʻoheheʻe keleawe i ke kiʻekiʻe kiʻekiʻe, ua hoʻokumu ʻia ka ʻalekole furfuryl. Hoʻohana ʻia kēia derivative nui i ka ʻoihana plastics no ka hana ʻana i nā ciment e pale i ka popopo a me nā mea hoʻoheheʻe ʻia. Hāʻawi ka hydrogenation like o ka waiʻona furfuryl ma luna o kahi nickel catalyst i ka wai ʻona tetrahydrofurfuryl, kahi i loaʻa ai nā esters like ʻole a me dihydropyran.

 I loko o kāna mau hopena ma ke ʻano he aldehyde, he ʻano like ka furfural me ka benzaldehyde. No laila, hoʻomaka ia i ka hopena Cannizzaro i ka alkali wai ikaika; ʻemi ia i furoin, C4H3OCO-CHOH-C4H3ʻO, ma lalo o ka mana o ka potassium cyanide; hoʻololi ʻia i hydrofuramide, (C4H3O-CH)3N2, e ka hana a ka amonia. Eia nō naʻe, ʻokoʻa ke ʻano o ka furfural mai benzaldehyde i kekahi mau ʻano, kahi e lilo ai kahi autoxidation i laʻana. I ke kū ʻana i ka lewa i ka mahana wela, hoʻohaʻahaʻa ʻia ka furfural a hoʻopaʻa ʻia i ka waikawa formic a me ka waikawa formylacrylic. ʻO ka Furoic acid kahi keʻokeʻo crystalline paʻa paʻa pono e like me kahi bactericide a me preservative ʻO kāna mau esters kahi wai wai ʻono i hoʻohana ʻia e like me nā mea hana i nā mea ʻala a me nā mea ʻono.


Ka manawa Post: ʻAuk-15-2020