晶化时间对ZSM-23分子筛物化性质及催化C4烯烃裂解性能的影响

考察了ZSM23分子筛在晶化过程中的变化规律及其在催化碳四烯烃裂解制乙烯、丙烯反应中的催化性能。采用XRD，SEM，TG-DTA，FT-IR等技术对不同晶化时间合成的ZSM23分子筛的结构、表面酸性进行了表征。结果表明，晶化时间为48h时，分子筛晶体开始出现；晶化72h时，无定形物相基本消失。当晶化时间从72h再延长至120h，ZSM-23分子筛的晶粒大小、形貌基本保持不变。以晶化时间为72h的ZSM-23分子筛制备的催化剂，在催化碳四烯烃裂解制乙烯、丙烯的反应中表现出最佳的催化性能，其乙烯加丙烯的收率达36．97％。

EFFECT OF CRYSTALLIZATION TIME ON PHYSICOCHEMICAL PROPERTIES AND C4 OLEFIN CATALYTIC CRACKING PERFORMANCE OF ZSM-23 ZEOLITE

The effect of crystallization time on physicochemical properties of ZSM-23 zeolite and its catalytic cracking performance of C 4 olefin to ethylene and propylene were investigated. XRD, SEM, TG-DTA and FT-IR were used to characterize the structure and surface acidity of the synthesized ZSM-23 zeolites at various crystallization times. It was found that the initial crystal formed at 48h and the amorphous phase disappeared at 72 h. When the crystallization time extended from 72 h to 120 h, the crystal shape and crystal size were basically remained unchanged. The catalyst prepared by the zeolite crystallized for 72 h showed the best catalytic cracking performance in the reaction of C 4 olefin to ethylene and propylene, the yield of ethylene plus propylene reached 36.97%.