Abstract
Catalysts corminins acid zeolitea a m more active, more selective to gasoline production, aad more stable in thermal and hydrothermal environmcnu [1–3]. It was esdznaud in 1973 that the selecdvky characmrisdcs of zeolite cmcklag araiysts were respoasible for a savings of aver 200 million bvrals of cmda oil per year oa the North Amartcan coadaent [4]. Acftpttp aa be madoat; zta Since purzeolita catalysts a n be forrnrrktad whtch are many orden of magnitude more acde than the older amorphous catalysts. Typid relative actidties of some zeoffte catalysts Uons are presented in Table 1. Considerafforu other than intrinsic-vie, for example. heat and mass tzuufer Umi Molu and/or equipment design factors, may set limits on the maximum aczivly. Today rkrtudly all commerchl cracktnq aulysts conraia zeolites.