REACTION OF BUTANES AN NA,H-Y ZEOLITES AND H-MORDENITES

The reaction chemistry for the conversion of isobutane and n-butane on H-mordenites was compared with that on Na,H-Y zeolites in continuous flow experiments. The close resemblance of the product distribution as a function of conversion suggests that identical mechanism for conver sion is effective on both types of zeolites, Hydrogen and methane from isobutane and in addition ethane and ethylene from n-butane were expe cted to be formed in chain initiation processes, while propene and but enes were expected to be formed in chain termination processes. The ma jor products, alkanes, are produced in chain carrying hydride and meth yl transfer, A rate of initiation approximately 10-fold higher than wi th mordenites having stronger Bronsted acid sites is required to reach identical conversion with Y-zeolites. The yield of individual product s on zeolites with identical structure and at identical temperature wa s almost independent of the Si/Al ratio or the Na+ content of zeolites but depended on the conversion; at identical conversion the chain len gth on zeolites with different activity was similar. (C) 1996 Academic Press, Inc.