Glacial acetic acid (CAS 64-19-7, Ntau dua lossis sib npaug ntawm 99.5-99.8% CH₃COOH)yog tsim industrially los ntawm chemical synthesis txoj kev uas ua ntej tsim dilute acetic acid, ua raws los ntawm multi-theem purification thiab dehydration distillation kom tshem tawm cov dej thiab kab impurities. Cov khoom siv thoob ntiaj teb yog tswj hwm los ntawm cov txheej txheem methanol carbonylation, uas suav rau feem ntau ntawm kev lag luam ntau lawm.
Tsis hais txog ntawm txoj kev tsim khoom, tag nrho cov glacial acetic acid kawg yuav tsum ua kom tau raws li cov kev cai purity nruj thiab muaj cov ntsiab lus dej tsawg los xyuas kom ruaj khov lub cev thiab tshuaj lom neeg.
Dab tsi yog Glacial Acetic Acid hauv Kev Tsim Khoom?
Glacial acetic acid yog hais txog anhydrous los yog muaj concentrated acetic acid uas solidifies ntawm 16.6 degree. Hauv kev xyaum ua lag luam, nws txhais tau tias yog acetic acid nrog cov dej tsawg heev, feem ntau tshaj 99.5% purity.
Txhua txoj kev tsim khoom tsim cov aqueous acetic acid ua ntej, thiab qib glacial tsuas yog ua tiav tom qab lub cev qhuav dej thiab kho cov txheej txheem.
Txoj Kev 1 - Methanol Carbonylation (Cov Txheej Txheem Tsim Nyog Ntiaj Teb)
Methanol carbonylation yog txoj kev lag luam tseem ceeb rau kev tsim cov acetic acid niaj hnub no. Nws muaj nyob rau hauv ob lub tshuab catalytic: cov txheej txheem Monsanto rhodium qub thiab cov txheej txheem Cativa iridium niaj hnub.
Cov txheej txheem Cativa tau dhau los ua cov thev naus laus zis zoo tshaj plaws rau cov chaw tsim khoom tshiab vim kev txhim kho catalyst stability, dej cov ntsiab lus hauv reactor system, thiab ntau dua tag nrho cov efficiency.
Monsanto Txheej Txheem (Rhodium Catalyst - Legacy Technology)
- Khoom noj khoom haus: Methanol thiab carbon monoxide
- Catalyst: Rhodium{0}}iodide complex
- Cov xwm txheej: 150-175 degree, 2-3 MPa
- Cov zis: High selectivity acetic acid nrog nruam rov ua dua ntawm cov roj tsis muaj zog
Cov txheej txheem no yog keeb kwm tseem ceeb tab sis tam sim no feem ntau hloov pauv hauv cov nroj tsuag tshiab.
Cov txheej txheem Cativa (Iridium Catalyst - Niaj hnub no tus qauv)
Cov txheej txheem Cativa, tsim los ntawm BP, tam sim no yog cov thev naus laus zis hauv kev teeb tsa tshiab.
Cov kev txhim kho tseem ceeb suav nrog:
- Iridium{0}}raws li catalyst system nrog iodide txhawb nqa
- Txo cov dej concentration hauv cov tshuaj tiv thaiv nruab nrab
- Txo cov khoom tsim tawm (xws li methyl acetate)
- Txhim kho catalyst lub neej thiab lub zog efficiency
Qhov no ua rau muaj txiaj ntsig zoo hauv qab dej purification thiab kev tsim khoom yooj yim ntawm siab -purity glacial acetic acid.
Purification thiab Distillation
Tom qab cov synthesis, crude acetic acid muaj:
- Dej
- Methanol
- Methyl acetate
- Txheeb xyuas cov catalyst residues
Purification muaj xws li:
- Lub teeb- xaus distillation (tshem tawm methanol thiab volatiles)
- Dehydration distillation (kev tshem tawm dej kom tsawg heev)
- Hnyav- xaus kev sib cais (tshem tawm cov organic impurities)
Cov khoom kawg yog khaws cia rau hauv lub tank stainless hlau nyob rau hauv kev tswj kub kub siab tshaj 16.6℃los tiv thaiv crystallization.
Txoj Kev 2 - Acetaldehyde Oxidation (Cov txheej txheem qub txeeg qub teg)
Acetaldehyde oxidation tau dav siv ua ntej methanol carbonylation los ua tus tseem ceeb.
- Khoom noj khoom haus: Ethylene → acetaldehyde → oxidation
- Catalyst: Manganese los yog cobalt ntsev
- Oxidant: Oxygen lossis cua
Kev txwv:
- Tsawg carbon efficiency piv rau carbonylation
- Kev tsim cov khoom lag luam siab dua
- Ntau dua kev khiav hauj lwm tus nqi ib tuj
Txoj kev no tam sim no txwv rau cov chaw tsim khoom me me lossis hauv cheeb tsam.
Txoj Kev 3 – Fermentation (Biological Production)
Fermentation siv cov kab mob Acetobacter oxidize ethanol rau hauv dilute acetic acid.
- Hom concentration: 5-15% acetic acid tov
- Khoom noj khoom haus: Ethanol los ntawm biomass
- Txheej txheem: Aerobic lom oxidation
Kev txwv:
- Cov zis heev dilute yuav tsum tau nthuav dav distillation
- Ntev ntau lawm voj voog
- Tsis economically haum rau tej glacial acetic acid ntau lawm
Txoj kev no feem ntau yog siv rau cov kua txiv hmab txiv ntoo thiab cov khoom noj tshwj xeeb- cov ntawv thov qib es tsis yog muaj glacial acetic acid.
Kev sib piv ntawm Txoj Kev Tsim Nyog
| Txoj kev | Kev Sib Koom | Kev siv yam | Qhov tseem ceeb Advantage | Kev txwv |
|---|---|---|---|---|
| Methanol Carbonylation (Cativa / Monsanto) | >90% | Cov khoom lag luam acetic acid ntau | High efficiency, scalable | Catalyst nqi & kev tswj corrosion |
| Oxidation ntawm acetaldehyde | <10% | Kev tsim khoom hauv cheeb tsam txwv | Cov cuab yeej siv yooj yim | Tsawg efficiency, ntau byproducts |
| Fermentation | <2% | Vinegar & khoom tshwj xeeb | Cov khoom noj tauj dua tshiab | Heev dilute cov zis |
Txoj Kev Ntau Lawm cuam tshuam li cas cov khoom qib
Tag nrho cov glacial acetic acid muaj cov qauv tshuaj tib yam (CH₃COOH), tsis hais txog kev tsim khoom. Qhov sib txawv ntawm kev tsim khoom feem ntau cuam tshuam rau qib impurity.
- Qib Industrial: Siv rau hauv coatings, textiles, chemicals
- Khoom noj khoom haus qib (FCC): Tswj impurities rau zaub mov daim ntawv thov (E260)
- Reagent Qib: Siab purity rau kev kuaj thiab kev siv tshuaj ntsuam xyuas
Purity yog tiav los ntawm kev tswj distillation thiab lub cev qhuav dej txheej txheem es tsis yog txoj kev synthesis nws tus kheej.
FAQ
Q1: Puas yog glacial acetic acid ncaj qha tsim nyob rau hauv reactors?
Tsis yog. Tag nrho cov txheej txheem ua ntej tsim cov aqueous acetic acid, tom qab ntawd purified thiab dehydrated.
Q2: Vim li cas methanol carbonylation siv dav?
Vim nws muaj kev ua haujlwm siab, tus nqi qis ib tuj, thiab scalable tas mus li ntau lawm.
Q3: Puas tuaj yeem fermentation siv rau kev lag luam glacial acetic acid?
Tsis yog. Nws tsim cov kev daws teeb meem zoo heev uas tsis yog kev lag luam tsim nyog rau bulk glacial - qib ntau lawm.
Q4: Vim li cas thiaj yuav tsum tau khaws cia glacial acetic acid siab tshaj 16.6 degree?
Vim tias nws solidifies hauv qab no qhov kub thiab txias, cuam tshuam rau kev tuav thiab hloov tshuab.
Xaus
Kev tsim khoom ntawm glacial acetic acid feem ntau yog raws li kev siv tshuab methanol carbonylation, tshwj xeeb tshaj yog cov txheej txheem Cativa niaj hnub. Lwm txoj hauv kev xws li acetaldehyde oxidation thiab fermentation yog txwv nyob rau hauv nplai lossis daim ntawv thov. Txawm li cas los xij ntawm txoj kev sib txuas, tag nrho cov khoom tau ua kom huv thiab lub cev qhuav dej kom ua tiav siab -purity glacial acetic acid haum raukev lag luam, khoom noj khoom haus, thiab kev sim siv.
