Process for increasing the selectivity of an alkylation catalyst for monoalkylation

摘要

A process for treating a molecular sieve-containing alkylation catalyst to increase its selectivity for monoalkylation in which the alkylation catalyst is contacted with a feedstock comprising at least one organic compound under conditions such that a sufficient amount of carbonaceous material evenly deposits on the alkylation catalyst to substantially suppress its alkylation activity. The carbon-containing catalyst particles are then subjected to combustion by contacting them with a gaseous oxidizing agent at an elevated temperature to remove at least a portion of the carbonaceous material, preferably substantially all of the carbonaceous material, thereby increasing the selectivity of the catalyst for monoalkylation by at least about 1.0 percentage point. The resulting alkylation catalyst can be used to alkylate benzene and other aromatic compounds with ethylene, propylene or other olefins to produce high yields of ethylbenzene, cumene and other alkylated products. Preferably, the alkylation catalyst contains an ammonium-exchanged and steam stabilized Y zeolite.