Qhov Tseem Ceeb - Distillation vs Extraction
Txawm hais tias distillation thiab extraction yog ob txoj kev sib cais ntawm lub cev feem ntau muaj qhov tseem ceeb hauv kev lag luam kom tau txais cov tshuaj ntshiab rau ntau daim ntawv thov, muaj qhov sib txawv ntawm distillation thiab extraction raws li lawv cov txheej txheem. Qhov sib txawv tseem ceeb ntawm distillation thiab extraction yog tias distillation ua raws li cua sov ntawm cov kua sib tov thiab sau cov vapor ntawm cov kua ntawm lawv cov boiling point thiab condensing lub vapor kom tau cov ntshiab tshuaj whereas, nyob rau hauv extraction, ib tug haum hnyav yog siv rau txoj kev sib cais..
Distillation yog dab tsi?
Distillation yog ib qho ntawm cov laus tshaj plaws, tab sis tseem siv ntau txoj kev sib cais ntawm cov kua sib tov, raws li qhov sib txawv ntawm lawv cov ntsiab lus kub. Nws suav nrog cua sov cov kua sib tov maj mam mus txog qhov kub ntawm cov kua hauv qhov sib tov, kom tau lawv cov vapor ntawm cov ntsiab lus kub sib txawv thiab ua raws li condensing lub vapor kom tau cov khoom ntshiab hauv cov kua.
Cov kua dej uas muaj cov ntsiab lus kub qis (cov tshuaj tsis haum xeeb tshaj plaws) tau muab rhaub ua ntej raws li cov khoom sib xyaw ua kom sov thaum cov khoom tsis muaj hluav taws xob tsawg nyob hauv qhov sib tov kom txog thaum qhov kub ntawm qhov sib tov nce mus rau lawv cov ntsiab lus kub. Ib txheej tsim tshwj xeeb ntawm cov cuab yeej siv rau cov txheej txheem distillation.
Dab tsi yog Extraction?
Cov txheej txheem ntawm kev rho tawm suav nrog kev tshem tawm tus neeg sawv cev lossis cov khoom pov tseg los ntawm cov khoom lossis cov kua sib tov, siv cov kuab tshuaj kom raug. Cov kuab tshuaj tsis yog tag nrho lossis ib nrab miscible nrog cov khoom lossis cov kua, tab sis nws yog miscible nrog tus neeg sawv cev. Tus neeg sawv cev nquag hloov ntawm cov khoom lossis cov kua sib tov mus rau qhov hnyav los ntawm kev sib cuag nrog cov khoom lossis cov kua. Cov theem sib xyaw hauv cov kuab tshuaj yog sib cais los ntawm centrifuging lossis lub ntiajteb txawj nqus sib cais txoj kev.
Extraction ntawm Petroleum
Dab tsi yog qhov txawv ntawm Distillation thiab Extraction?
YDistillation thiab Extraction Method
Txoj Kev Distillation
Xav txog cov kua sib xyaw nrog plaub cov kua A, B, C thiab D.
Boiling points: Bpkua A (TA) > Bpkua B (T B) > Bpkua C(TC) > Bpliquid D(TD)
(tsawg volatile compound) (Feem ntau volatile compound)
Kub ntawm qhov sib tov=Tm
Thaum cua sov cov kua sib tov, cov kua dej tsis haum tshaj plaws (D) tawm hauv qhov sib tov ua ntej, thaum qhov kub ntawm qhov sib tov sib npaug rau nws qhov kub kub (Tm=T D) thaum lwm cov kua tseem nyob hauv qhov sib tov. Cov vapor ntawm kua D yog sau thiab condensed kom tau cov kua ntshiab D.
Raws li cov kua tau rhaub ntxiv, lwm cov kua kuj boils tawm ntawm lawv cov ntsiab lus kub. Raws li cov txheej txheem distillation txuas ntxiv, qhov kub ntawm qhov sib tov nce.
Extraction Method
Xav txog ib yam khoom nquag A yog nyob rau hauv kua B thiab lawv yog miscible kiag li. Cov kuab tshuaj C yog siv los cais A los ntawm B. Kua B thiab kua C tsis miscible.
1: Tshuaj A yog yaj hauv kua A
2: Tom qab ntxiv cov kuab tshuaj C, qee cov molecules hauv kua A mus rau hnyav C
3: Raws li lub sijhawm dhau mus ntau cov molecules mus rau qhov hnyav C. (Solubility ntawm A hauv cov kuab tshuaj ntau dua li cov kua A)
4: Cov kuab C yog cais los ntawm cov kua A vim lawv tsis tuaj yeem. Lwm txoj kev yog siv los cais A los ntawm cov kuab tshuaj.
Ntau qhov kev rho tawm tau ua tiav kom sib cais tag nrho A los ntawm cov kuab tshuaj B. Kub yog qhov tsis tu ncua hauv cov txheej txheem no.
Distillation thiab Extraction hom
Distillation: Txoj kev siv distillation feem ntau yog "qhov yooj yim distillation" thiab "fractional distillation." Yooj yim distillation yog siv thaum cov kua sib cais muaj cov ntsiab lus sib txawv heev. Fractional distillation yog siv thaum ob lub kua dej sib cais muaj ze li ntawm cov ntsiab lus kub tib yam.
Extraction: Hom kev rho tawm feem ntau yog "khoom - kua rho tawm" thiab "kua - kua rho tawm." Khoom - kua extraction yuav cais ib yam khoom los ntawm ib tug khoom siv ib tug hnyav. Kua - kua extraction yuav cais ib yam khoom los ntawm ib tug kua siv ib tug hnyav.
Daim ntawv thov ntawm Distillation thiab Extraction
Distillation: Txoj kev sib cais no yog siv nyob rau hauv cov feem ntau distillation ntawm cov roj crude, tshuaj thiab roj av kev lag luam. Piv txwv li, cais benzene los ntawm toluene, ethanol los yog methanol los ntawm dej thiab acetic acid los ntawm acetone.
Extraction: Nws yog siv los cais cov organic tebchaw xws li phenol, aniline thiab nitrated aromatic compounds los ntawm dej. Nws kuj tseem siv tau los rho cov roj yam tseem ceeb, tshuaj, tsw qab, tshuaj tsw qab thiab khoom noj khoom haus.
Image Courtesy: "Kev rho tawm cov roj siv chav" los ntawm Micov ntawm English Wikipedia. (CC BY-SA 3.0) via Commons
