Patent ID: 8937209
Filing Date: 2015-01-20
Classification: B01D,C07C

Abstract:
1. A process for separating para-xylene from a plurality of aromatic compounds, the process comprising: treating a feed stream comprising a plurality of aromatic compounds in a xylene fractionation unit, and feeding xylenes, C7-aromatics and light impurities from the the xylene fractionation unit to a first extract column to produce a first mixed xylene stream, which is a bottoms stream comprising a plurality of xylene isomers, and an overhead stream comprising C7-aromatics and light impurities; introducing said first mixed xylene stream into a first adsorptive separation unit to produce a first para-xylene enriched stream and a first raffinate stream, wherein the first raffinate stream is an overhead stream; introducing a second mixed xylene stream, comprising the overhead stream from the first extract column in combination with another stream that includes a plurality of xylene isomers, into a second adsorptive separation unit to produce a second para-xylene enriched stream and a second raffinate stream, wherein the second raffinate stream is a bottoms stream; combining para-xylene from said second para-xylene enriched stream with said first mixed xylene stream, within said first extract column, upstream of said first adsorptive separation unit; and feeding both said first raffinate stream and said second raffinate stream into a raffinate column, and further comprising using a heavy desorbent in said first adsorptive separation unit and using a light desorbent in said second adsorptive separation unit.