4A molecular sieve is mainly used to make static dehydration in airtight gas or liquid system, it can remove the moleculars of e The ZSM-5 molecular sieve is prepared through hydrothermal process by using oxide, oxy-acid, salt or complex containing Al, Ga, B, Fe, Cr, V, Zr or As element as M source; tetracethyl silicate, silica sol or water glass as Si source; and recovered molecular sieve ...