VERFAHREN ZUR ALKYLIERUNG UND TRANSALKYLIERUNG MIT INTEGRIERTEN WÄRMEAUSTAUSCH

摘要

The present invention addresses heat integration in an alkylation/transalkylation process involving alkylation of an aromatic substrate with a C2-C4 alkylating agent coupled with separation to recover a monoalkylated aromatic product and liquid phase transalkylation of a polyalkylated product. Aromatic feedstock and a C2-C4 alkylating agent are supplied to an alkylation reaction zone which is operated to produce an alkylated product. The output from the alkylation reaction zone initially travels through an arrangement of heat exchangers. From there, the alkylation effluent passes into the first separation zone which is operated to produce a lower boiling fraction comprising the aromatic substrate, which may be recycled to the alkylation reaction zone, and a higher boiling fraction comprising a mixture of monoalkylated and polyalkylated aromatics. This lower boiling fraction first travels back through portions of the heat exchanger arrangement on the way to recycle into the alkylation zone. The higher boiling fraction of the first separation zone is supplied to a secondary separation zone to produce a second lower boiling fraction comprising the desired monoalkylated product and a higher boiling fraction comprising polyalkylated product. At least a portion of the higher boiling polyalkylated fraction passes through a portion of the heat exchanger arrangement into a transalkylation reaction zone containing a molecular sieve transalkylation catalyst operated under liquid phase conditions to cause disproportionation of the polyalkylated fraction to arrive at a disproportionation product having a reduced polyalkylated aromatic content and an enhanced monoalkylated aromatic content.