Hauv kev tshawb nrhiav tshiab, cov kws tshawb fawb tau tshawb nrhiav txog qhov ua tau zoo ntawm ntau yam hmoov molecular sieve hauv kev tswj cov pa phem. Kev tshawb nrhiav tau tsom mus rau ntau yam molecular sieves, suav nrog 3A, 5A, 10X, 13X, NaY, MCM-41-Al, thiab MCM-41-Si, lub hom phiaj yog txheeb xyuas lawv lub peev xwm hauv kev txo cov pa phem thaum lub sijhawm ua haujlwm hauv kev lag luam.
Kev tswj cov pa phem yog qhov teeb meem tseem ceeb hauv ntau lub lag luam, tshwj xeeb tshaj yog cov uas muaj kev ua haujlwm kub siab xws li kev ua hlau, kev vuam, thiab kev tsim tshuaj lom neeg. Kev tso tawm cov pa phem tuaj yeem ua rau muaj kev pheej hmoo loj rau kev noj qab haus huv rau cov neeg ua haujlwm thiab ua rau muaj kuab paug rau ib puag ncig. Yog li ntawd, qhov xav tau cov txheej txheem tswj cov pa phem zoo yeej tsis tau muaj dua li no.
Cov molecular sieves yog cov khoom siv crystalline nrog cov qhov loj sib npaug uas tuaj yeem nqus cov molecules raws li lawv qhov loj me thiab cov duab. Cov yam ntxwv tshwj xeeb no ua rau lawv zoo tagnrho rau ntau yam kev siv, suav nrog kev sib cais roj, catalysis, thiab, raws li kev tshawb fawb no qhia, kev tshem tawm pa phem. Cov kws tshawb fawb nrhiav kev soj ntsuam kev ua tau zoo ntawm cov hmoov molecular sieve sib txawv hauv kev ntes thiab tshem tawm cov pa phem.
Txoj kev tshawb fawb tau pib nrog kev tshuaj xyuas tag nrho ntawm cov khoom ntawm cov molecular sieves xaiv. Cov 3A thiab 5A sieves, uas paub txog lawv lub peev xwm los nqus cov molecules me me, tau raug sim ua ke nrog cov pore sieves loj dua, xws li 10X thiab 13X, uas tuaj yeem tuav cov roj molecules loj dua. Lub NaY sieve, ib hom zeolite, kuj tau suav nrog vim nws thaj chaw siab thiab muaj peev xwm pauv ion. Tsis tas li ntawd, cov MCM-41 variants, MCM-41-Al thiab MCM-41-Si, tau raug xaiv rau lawv cov qauv mesoporous tshwj xeeb, uas muab cov txheej txheem adsorption sib txawv piv rau cov zeolites ib txwm muaj.
Cov theem sim no suav nrog kev muab cov hmoov molecular sieve rau hauv ntau yam txheej txheem tsim pa taws, ua piv txwv txog cov xwm txheej uas feem ntau pom muaj nyob rau hauv cov chaw ua haujlwm. Cov kws tshawb fawb ntsuas qhov ua tau zoo ntawm txhua lub sieve hauv kev ntes pa taws, tshuaj xyuas cov yam xws li lub peev xwm nqus tau, qhov nrawm ntawm kev ntes pa taws, thiab qhov ua tau zoo tag nrho hauv kev txo cov pa phem ntawm cov tshuaj lom neeg hauv huab cua.
Cov txiaj ntsig pib qhia tau hais tias kev ua tau zoo ntawm cov molecular sieves sib txawv ntau heev raws li lawv cov khoom sib xyaw thiab cov qauv. Cov 3A thiab 5A sieves tau ua pov thawj txog kev muaj peev xwm zoo kawg nkaus hauv kev nqus cov pa me me, ua rau lawv haum rau cov ntawv thov uas muaj cov khoom me me yog qhov txhawj xeeb. Ntawm qhov tod tes, cov pore sieves loj dua, tshwj xeeb tshaj yog 10X thiab 13X, tau ua tau zoo heev hauv kev ntes cov roj molecules loj dua, qhia txog lawv qhov kev siv tau zoo hauv cov txheej txheem uas tsim cov pa hnyav dua.
Lub tshuab nqus pa NaY tau qhia txog cov yam ntxwv zoo kawg nkaus ntawm kev pauv ion, uas tsis yog tsuas yog ua kom nws cov pa luam yeeb zoo dua xwb tab sis kuj tseem ua rau muaj kev tshem tawm qee yam tshuaj lom. Tus cwj pwm no ua rau NaY ua tus neeg sib tw zoo rau cov lag luam uas ua haujlwm nrog cov khoom phom sij, qhov twg ob qho tib si kev tshem tawm pa luam yeeb thiab kev tshem tawm tshuaj lom neeg yog qhov tseem ceeb.
MCM-41-Al thiab MCM-41-Si, nrog lawv cov qauv mesoporous tshwj xeeb, muab txoj hauv kev sib txawv rau kev tshem tawm cov pa phem. Lawv thaj chaw siab thiab qhov loj me ntawm cov qhov tso zis tau tso cai rau kev nqus cov khoom pa phem tshwj xeeb, ua rau lawv muaj ntau txoj hauv kev rau cov tswv yim tswj cov pa phem. Kev tshawb fawb tau hais txog lub peev xwm ntawm cov ntaub ntawv no hauv kev tsim cov txheej txheem lim dej siab heev uas tuaj yeem hloov kho rau ntau yam kev xav tau ntawm kev lag luam.
Thaum txoj kev tshawb fawb mus ntxiv, pab neeg kuj tau tshawb nrhiav txog lub peev xwm rov ua dua tshiab ntawm cov molecular sieves. Lub peev xwm los rov qab kho lub peev xwm nqus ntawm cov sieves tom qab siv yog qhov tseem ceeb rau lawv txoj kev siv hauv kev lag luam. Kev tshawb fawb pom tias feem ntau ntawm cov sieves uas tau sim tuaj yeem rov ua dua tshiab tau zoo los ntawm kev kho cua sov, uas tso cai rau kev siv rov qab yam tsis muaj kev poob qis ntawm kev ua haujlwm.
Cov txiaj ntsig ntawm txoj kev tshawb fawb no tsis yog tsuas yog txo cov pa phem xwb. Los ntawm kev txheeb xyuas thiab ua kom zoo dua ntawm kev siv cov hmoov molecular sieve, cov lag luam tuaj yeem txo lawv cov teeb meem ib puag ncig thiab txhim kho kev nyab xeeb hauv chaw ua haujlwm. Cov kev tshawb pom qhia tias kev koom ua ke cov ntaub ntawv no rau hauv cov txheej txheem tswj cov pa phem uas twb muaj lawm tuaj yeem ua rau muaj kev coj ua zoo dua thiab ruaj khov dua.
Xaus lus, txoj kev tshawb fawb tshiab no qhia txog lub peev xwm ntawm cov hmoov molecular sieve ua cov neeg sawv cev zoo rau kev tswj cov pa phem. Nrog lawv cov khoom tshwj xeeb thiab peev xwm, cov sieves xws li 3A, 5A, 10X, 13X, NaY, MCM-41-Al, thiab MCM-41-Si muab cov kev daws teeb meem zoo rau cov teeb meem uas tshwm sim los ntawm cov pa phem hauv cov txheej txheem kev lag luam. Thaum cov lag luam txuas ntxiv nrhiav kev ua haujlwm ruaj khov thiab muaj kev nyab xeeb, cov kev nkag siab tau los ntawm kev tshawb fawb no tuaj yeem ua rau txoj hauv kev rau kev tsim cov thev naus laus zis tswj cov pa phem uas muab qhov tseem ceeb rau kev noj qab haus huv thiab kev tiv thaiv ib puag ncig. Kev tshawb fawb ntxiv thiab kev koom tes ntawm cov tsev kawm ntawv thiab kev lag luam yuav tseem ceeb heev rau kev txhais cov kev tshawb pom no rau hauv kev siv tau, thaum kawg pab txhawb rau thaj chaw kev lag luam huv dua thiab muaj kev nyab xeeb dua.
Lub sijhawm tshaj tawm: Lub Kaum Ob Hlis-19-2024
