Mono ethylene glycol (MEG) feem ntau yog tsim los ntawm ethylene oxide (EO) hydration txheej txheem, qhov twg ethylene yog thawj oxidized rau ethylene oxide thiab ces reacted nrog dej nyob rau hauv kev tswj tej yam kev mob los tsim MEG, feem ntau nrog me me ntawm diethylene glycol (DEG) thiab triethylene glycol (TEGlycol).
Ethylene Oxide Formation Stage
Monoethylene glycol ntau lawm pib nrog oxidation ntawm ethylene siv ib cov nyiaj -raws li catalyst, qhov chaw muaj nroj tsuag feem ntau ua tau ethylene oxide selectivity ntawm ib ncig ntawm 70-80% ib kis, nrog oxygen raws li cov oxidant. Cov kauj ruam no yog exothermic heev thiab sawv cev rau lub hauv paus ntawm kev hloov dua siab tshiab nyob rau hauv petrochemical complexes, raws li ethylene nws tus kheej yog muab los ntawm qhov cub tawg ntawm hydrocarbons ntawm qhov kub siab tshaj 800 degree. Qhov ua tau zoo ntawm theem no cuam tshuam ncaj qha rau hauv qab MEG tawm los thiab kev lag luam tag nrho.
Ethylene Oxide Hydration Txheej txheem
Ethylene oxide yog tom qab ntawd hloov mus rau hauv MEG los ntawm hydration nrog dej, qhov uas cov txheej txheem ib txwm ua haujlwm nrog dej - mus rau -EO molar ratio feem ntau tshaj 20: 1 los txwv los ntawm - cov khoom tsim. Hauv cov txheej txheem kev lag luam,MEG glycolselectivity yog kwv yees li 85-90%, txhais tau hais tias mus txog 10-15% ntawm cov ntaub ntawv tso zis hnyav dua glycols xws li DEG thiab TEG. Los ntawm qhov sib piv, cov txheej txheem catalytic zoo li cov txheej txheem OMEGA tuaj yeem ua rau MEG xaiv ntau dua 99%, txo cov nqi sib cais thiab txhim kho atom efficiency.
Los ntawm -Kev Tsim Khoom thiab Tswj Txheej Txheem
Thaum lub sij hawm hydration, lwm yam tshwm sim tshwm sim thaum ethylene oxide reacts nrog twb - tsim MEG molecules, tsim DEG thiab TEG raws li qhov tseem ceeb los ntawm - khoom. Cov kev cuam tshuam sab no ua qhov tseem ceeb ntawm qhov kub siab, feem ntau siab dua 180 degree, yuav tsum tau tswj cov txheej txheem nruj dua qhov kub, siab, thiab kev ua haujlwm catalyst. Piv nrog rau cov dej ib txwm siv, cov tshuab ua kom zoo tuaj yeem txo DEG / TEG tsim los ntawm ntau dua 80%, txhim kho cov khoom purity thiab txo qis qis zog distillation xav tau.
Purification thiab Separation Stage
Crude glycol mixs yog purified siv multi-stage distillation, qhov twg MEG yog sib cais raws li nwskub pointntawm kwv yees li 197.3 degree. Kev lag luam distillation txhua ua haujlwm nyob rau hauv kev txo qis los txhim kho lub zog efficiency thiab tiv thaiv thermal degradation ntawm glycols. Cov kauj ruam ua kom huv zaum kawg, suav nrog kev lim dej thiab tshuaj kho mob, xyuas kom MEG purity qib ncav cuag ntau dua lossis sib npaug li 99.8% rau fiber ntau- qib kev siv, uas yog qhov tseem ceeb rau PET polymerization kev ua tau zoo thiab sib xws.
Alternative Coal-rau-MEG Route
Hauv cov thee- thaj chaw nplua nuj, Mono-ethylene glycol (cas no 107-21-1) kuj tuaj yeem tsim los ntawm cov thee-rau-}MEG (CTMEG) txoj kev, uas hloov cov thee rau hauv syngas, tom qab ntawd methanol, dimethyl oxalate thiab thaum kawg. Piv nrog rau ethylene{10}}raws li kev tsim khoom, CTMEG txoj kev yog cov khoom noj khoom haus ntau dua, tab sis feem ntau ua rau muaj cov pa roj carbon ntau dua, nrog rau lub neej emissions kwv yees li 20-40% siab dua li cov txheej txheem ethylene-raws li cov txheej txheem tshwj tsis yog kev koom ua ke nrog carbon capture systems.
Muaj zog thiab txheej txheem Efficiency
Monoethylene glycol (Ethane-1,2-diol) ntau lawm yog lub zog- siv zog, nrog kev sib xyaw ethylene oxide thiab glycol nroj tsuag siv kwv yees li 20-25 GJ ntawm lub zog ib tuj ntawm MEG tsim. Niaj hnub nimno siab- cov txheej txheem xaiv tau txo cov kev xav tau ntawm lub zog los ntawm kev txo qis qis qis qis, thaum cov txheej txheem xaiv qis qis yuav tsum tau siv zog ntau dua thiab siv hluav taws xob vim yog kev faib tawm ntau ntawm cov khoom lag luam. Qhov no ua rau kev xaiv cov txheej txheem yog qhov tseem ceeb hauv cov qauv nqi thiab kev ua haujlwm ib puag ncig ntawm MEG kev tsim khoom.
