I-molecular sieve 3A, ekwabizwa ngokuba yi-molecular sieve KA, ene-aperture emalunga ne-3 angstroms, ingasetyenziselwa ukomisa iigesi kunye nolwelo kunye nokuphelelwa ngamanzi emzimbeni kwee-hydrocarbons.Ikwasetyenziswa ngokubanzi ukomisa petroli, iigesi eziqhekekileyo, i-ethylene, ipropylene kunye neegesi zendalo.
Umgaqo osebenzayo we-molecular sieves unxulumene ikakhulu nobukhulu bepore yeesefu ze-molecular, eziyi-0.3nm/0.4nm/0.5nm ngokulandelelanayo.Ziyakwazi ukubhengeza iimolekyuli zerhasi ezinobubanzi bemolekyuli buncinci kunobukhulu bepore.Ubukhulu besayizi yepore, ubukhulu be-adsorption umthamo.Ubungakanani bepore bahlukile, kwaye izinto ezihluzwayo kwaye zahluliwe nazo zahlukile.Ngamagama alula, i-3a ye-molecular sieve inokubhengeza kuphela iimolekyuli ezingaphantsi kwe-0.3nm, i-4a ye-molecular sieve, ii-molecule ze-adsorbed kufuneka zibe ngaphantsi kwe-0.4nm, kunye ne-5a ye-molecular sieve iyafana.Xa isetyenziswe njenge-desiccant, i-molecular sieve inokuthatha ukuya kwi-22% yobunzima bayo kumswakama.