Tam sim no, nyob rau hauv cov txheej txheem ntawm cov roj purification, feem ntau siv adsorbents muaj xws li silica gel, activated alumina, activated bauxite, molecular sieves, thiab lwm yam. Activated carbon muaj peev xwm lub cev qhuav dej me ntsis thiab feem ntau yog siv los rov qab kua hydrocarbons los ntawm cov nkev roj.
Nws cov khoom tseem ceeb yog ntxeem tau thiab amorphous aluminium oxide, thiab muaj me me ntawm lwm cov hlau sib txuas. Activated alumina yog polar adsorbent uas ruaj khov rau feem ntau cov pa roj thiab vapors. Nws yog cov khoom tsis muaj tshuaj lom uas yuav tsis muag, o los yog tawg thaum muab tso rau hauv dej los yog kua. Nws muaj peev xwm tiv taus qhov cuam tshuam thiab hnav muaj zog. Nws yog feem ntau siv rau lub cev qhuav dej thiab ziab ntawm cov roj, roj thiab cov khoom siv petrochemical. Cov roj dew point ntawm activated alumina tom qab ziab tuaj yeem qis li -73 degree . Tom qab activated alumina yog recycled, nws cov khoom hloov me ntsis.
Qhov no yog ib qho nyuaj amorphous saw-zoo li thiab network-zoo li silicic acid polymer particle, uas yog hydrophilic polar adsorbent. Cov mis molecular ntawm silica gel yog SiO2·nH2O, thiab nws txoj kab uas hla yog 2-20nm. Silica gel muaj kev xaiv pom tseeb rau polar molecules thiab unsaturated hydrocarbons, yog li nws tuaj yeem ua rau lub cev qhuav dej nrog cov nkev ntuj.
Qhov no yog ntuj lossis hluavtaws zeolite-hom silicate. Ntuj molecular sieves tseem hu ua zeolites, thaum cov hluavtaws feem ntau hu ua molecular sieves.
Lub cev muaj zog ntawm molecular sieves nyob ntawm lawv cov tshuaj muaj pes tsawg leeg thiab cov qauv siv lead ua. Muaj ntau txoj hauv kev nrog cov pore diameters thiab cov qhov zoo sib xws hauv cov qauv ntawm molecular sieves. Cov pores no tsis tsuas yog muab cov cheeb tsam loj tshwj xeeb, tab sis tsuas yog tso cai rau cov molecules nrog txoj kab uas hla me dua qhov pore loj nkag mus, thaum cov molecules loj dua qhov pore loj nkag tsis tau, ua rau cov molecular sieve xaiv rau adsorbing molecules.
Molecular sieves tuaj yeem muab faib ua cov qauv sib txawv raws li qhov loj ntawm qhov pores thiab cov khoom sib piv ntawm SiO2 rau Al2O3 hauv molecular sieve. X-hom molecular sieve muaj peev xwm adsorb tag nrho cov molecules uas yuav adsorbed los ntawm A-hom molecular sieve, thiab muaj ib tug me ntsis dua noo noo peev xwm.
