ABSTRACT

This chapter discusses aluminosilicate, aluminophosphate, and silicoaluminophosphate as zeolite. In addition, zeolites have ordered micropore channels in their crystalline structure and exhibit unique adsorption and molecular sieving properties based on their micropore systems. The chapter focuses on improving permeability through the intracrystalline pathways to increase permeation properties. It introduces the state of the art of zeolite membrane research for gas separation. Permeation through a few intercrystalline pathways easily spoils separation performance. Thus, reducing the intercrystalline pathways would help zeolite membranes to improve permselectivity. Light hydrocarbon gas mixtures are also important targets for separation with inorganic membranes. In addition, some sorts of zeolite membranes separate saturated and unsaturated hydrocarbons by using affinity difference. The principle of gas separation using zeolite membranes is mainly based on the molecular sieving effect. Zeolite membranes are able to separate molecules smaller than the micropore of the zeolite and larger molecules that cannot enter the micropore.