GB1277457A - Process for aromatic conversion and fractionation - Google Patents

Abstract

1277457 Xylenes and ethyl benzene FLUOR CORP Ltd 16 June 1969 30458/69 Heading C5E Feedstocks comprising xylenes and ethyl benzene are subjected to a combined separation/ conversion process sequence comprising the steps of: (a) Introducing said feed at a first feed tray of a multilevel fractional distillation zone; (b) Taking from said zone the following streams: (i) an overhead stream comprising predominantly ethyl benzene, (ii) a bottoms stream comprising predominantly o-xylene and including heavy ends, and (iii) a sidestream comprising predominantly p-xylene and mxylene, this sidestream being taken at a level below the feed-introduction level; (c) Processing the sidestream (iii) to recover therefrom p-xylene by crystallization; (d) Isomerizing the remainder of the sidestream, i.e. the mother liquor from step (c), to convert m-xylene to other xylene isomers; and (e) Returning the isomerization effluent to the fractionation zone at a second feed tray which is below the level at which sidestream (iii) is withdrawn. The ethyl benzene and o-xylene streams may be further fractionated to recover the pure isomers, and if desired the o-xylene may be sent to the isomerization zone to maximize p-xylene production.