A ZSM-5 zeolite-based catalyst for oligomerization of the butane–butylene fraction

The effect of localization of acid sites and the nature of the modifier metal on the activity, selectivity, and operation stability of a ZSM-5 zeolite-based catalyst in the oligomerization of the butane–butylene fraction (BBF) has been examined. It has been shown that the selective poisoning of acid sites on the external surface of zeolite crystals reduces coking and increases the yield of the desired gasoline fraction. Introduction of a promoter metal insignificantly affects the catalytic properties of the zeolite. Among Zn, Ga, and La, gallium appears to be the best modifier, which provides an increase in the yield of the desired gasoline fraction by 0.9%. As a result of the study, a BBF oligomerization catalyst has been developed that ensures a threefold increase in the catalyst on-stream time and a 7% increase in the yield of the gasoline fraction as compared with its commercial counterpart.