ZSM-5 - AN ACTIVE, SELECTIVE AND STABLE CATALYST FOR SKELETAL ISOMERIZATION OF N-BUTENE

A series of H-ZSM-5 catalysts with a varying Si/Al ratio, varying part icle size and varying substitution (Fe for Al) has been studied in ske letal isomerisation of n-butene in continuous flow experiments. The va rious H-ZSM-5 catalysts which, unlike the other 10-membered ring molec ular sieves, show a very low selectivity at standard conditions, have been used under modified reaction conditions. After changes on the cat alyst, and under optimised conditions ZSM-5 showed rather high selecti vity and yield of isobutene. The just mentioned modifications were sug gested on basis of the knowledge on the mechanism of skeletal isomeris ation and of the accompanying side reactions. (C) 1997 Elsevier Scienc e B.V.