Recovery of Olefins from Para-Xylene Process

摘要

A process for producing para-xylene, by (a) contacting toluene with methanol in the presence of an alkylation catalyst under conditions effective to produce an alkylation effluent comprising xylenes and a by-product mixture comprising water, dimethyl ether and C4−hydrocarbons; (b) separating the alkylation effluent into a first fraction containing xylenes and a second fraction containing the by-product mixture; (c) removing water from the second fraction to produce a dried by-product mixture; (d) fractionating the dried by-product mixture to separate the mixture into a bottoms stream containing dimethyl ether and an overhead stream containing at least some of the C4- hydrocarbons; and (e) recovering ethylene and propylene from the overhead stream.