US Patent 8242320 Cumene production with high selectivity

Cumene production methods are disclosed, based on the alkylation of benzene with propylene, in which byproducts of the alkylation reaction are advantageously reduced to achieve a high cumene selectivity. This may be attained by (i) reducing the portion of the total alkylation effluent that is recycled, after cooling, to the alkylation reaction zone for quenching or direct heat exchange and/or (ii) reducing the benzene:propylene molar ratio of the alkylation feedstock. To manage the temperature differential across catalyst bed(s) in the alkylation reaction zone, indirect heat exchange may be used to remove heat.