CPC C07C 7/12 (2013.01) [B01D 15/1821 (2013.01); B01D 61/38 (2013.01); B01D 69/142 (2013.01); C07C 15/08 (2013.01)] | 25 Claims |
1. A process for separating paraxylene (PX) from a mixture of PX, metaxylene (MX), orthoxylene (OX), and ethylbenzene (EB), comprising the steps of:
(i) processing a feed stream, comprising the mixture, and a desorbent supply stream, comprising desorbent, in a simulated moving bed adsorption apparatus to produce an extract stream comprising desorbent enriched in PX and a raffinate stream comprising desorbent lean in PX;
(ii) fractionating the extract stream to produce a first desorbent-rich stream and a PX-rich stream;
(iii) fractionating the raffinate stream to produce a second desorbent-rich stream and a mixed-C8-aromatic-rich stream;
(iv) introducing a supply stream comprising at least a portion of one or both of the first desorbent-rich stream, the second desorbent-rich stream, or a combination thereof to a membrane separator to produce a permeate stream and a retentate stream, wherein the retentate stream is rich in non-aromatics relative to the permeate stream;
(v) supplying the permeate stream and any remaining portion(s) of the first desorbent-rich stream, the second desorbent-rich stream, or the combination thereof, to the desorbent supply stream to the simulated moving bed adsorption apparatus; and
(vi) purging the retentate stream from the process.
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