Catalytic alkylation of benzene to cumene using propylene - using Friedel-Crafts catalysts and partial effluent recycle

摘要

Cumene is prepd. by: (A) alkylating propylene with excess benzene in presence of an alkylation catalyst; (B) dividing the total liq. effluent into =2 portions of like compsn. (C) recirculating one of the portions of the effluent to the reaction zone; (D) introducing another portion and a transalkylation effluent stream (defined below) into a sepn. zone; (E) sepg. from the admixed effluents streams rich in benzene, cumene and di- and triisopropylbenzene; (F) transalkylating the last-named stream in presence of a transalkylating catalyst to form additional cumene; (G) supplying the transalkylation effluent stream; (H) passing at least a portion of the benzene-rich stream from the sepn. zone to the alkylation reaction zone; and (I) recovering the cumene prod. stream from the sepn. zone. The process is applicable broadly to the prodn. of alkylated aromatic hydrocarbons and esp. to the prodn. in improved yields, of cumene.