Hydrothermal synthesis, hydrothermal conversion thiab ion pauv:
Hydrothermal synthesis yog siv los tsim cov khoom uas muaj purity siab dua thiab los ua ke cov molecular sieves tsis pom nyob rau hauv cov xwm. Lub silicon uas muaj cov compound (dej iav, silicon sol), txhuas compound (hydrated alumina, txhuas ntsev) thiab alkali (sodium hydroxide thiab potassium hydroxide) thiab dej proportionately, cua sov lub sij hawm nyob rau hauv autoclave, nag lossis daus ntawm zeolite crystals. Cov txheej txheem synthesis tuaj yeem raug nthuav tawm raws li kev txiav txim qis dua:
Nyob rau hauv lub xub ntiag ntawm ntau alkali, lub hydrothermal hloov dua siab tshiab ntawm cov khoom txhuas silicate brine rau hauv ib tug molecular sieve. Cov khoom siv raw siv yog kaolin, bentonite, diatomite, thiab lwm yam, thiab cov khoom siv hluavtaws silica aluminium gel tuaj yeem siv tau. Cov qauv no muaj tus nqi qis, tab sis qhov purity ntawm cov khoom yog tsawg dua li ntawm hydrothermal synthesis.
Ion txauv feem ntau hloov cov Na zeolite mus rau hauv ib qho molecular sieve uas muaj cov cations xav tau hauv cov kua dej. General formula yog raws li nram no:
Hauv cov mis, Z- sawv cev rau cov pob txha anion, thiab kuv ntxiv yog cov cations uas yuav tsum tau pauv, xws li NH4 ntxiv, Ca2 ntxiv, Mg2 ntxiv, Zn2 ntxiv, thiab lwm yam. cov khoom siv raw feem ntau yog chloride, sulfate, thiab nitrate. Nyob rau hauv cov kev daws teeb meem ntawm sib txawv cation pauv mus rau molecular sieve ntawm txawv degrees ntawm nyuaj, hu ua sieve kev txiav txim, piv txwv li: cov cationic molecules ntawm 13X zeolite yog Ag ntxiv, Cu2 ntxiv, xaiv H ntxiv, Ba2 ntxiv, Au3 ntxiv, Th4 ntxiv, Sr2. plus , Hg2 plus , Cd2 plus , Zn2 plus , Ni2 plus , Ca2 plus , Co2 plus , NH4 K plus , Au2 plus , Na plus plus , Mg2 plus , and Li plus . Cov nram qab no tsis: cov kev sib pauv kev sib pauv degree, Na plus pauv accounted rau feem pua ntawm molecular sieve cia nyob rau hauv thawj tus nqi ntawm Na plus ; pauv peev xwm, pauv rau txhua 100 moles ntawm sieve hauv cationic milligram sib npaug; txauv efficiency, hais tias qhov kev daws rau qhov loj feem pua ntawm cation pauv ntawm molecular sieve. Txhawm rau ua kom tsim nyog molecular sieve catalysts yog xav tau los pauv cov khoom lag luam nrog lwm cov khoom siv thiab kev xa tawm ntawm cov khoom siv no yuav yog lwm cov catalysts, catalyst thiab diluent los yog nplaum, npaj los ntawm molding khoom activated catalyst tuaj yeem nqa tawm.