US 11,673,848 B2
Xylene separation processes using a membrane separator
Oluwagbogo Adebayo-Ige, Houston, TX (US); Robert G. Tinger, Friendswood, TX (US); Todd E. Detjen, Bellaire, TX (US); and Bhupender S. Minhas, Bridgewater, NJ (US)
Assigned to ExxonMobil Chemical Patents Inc., Baytown, TX (US)
Appl. No. 17/795,901
Filed by ExxonMobil Chemical Patents Inc., Baytown, TX (US)
PCT Filed Jan. 11, 2021, PCT No. PCT/US2021/012908
§ 371(c)(1), (2) Date Jul. 28, 2022,
PCT Pub. No. WO2021/173238, PCT Pub. Date Sep. 2, 2021.
Claims priority of provisional application 62/982,425, filed on Feb. 27, 2020.
Claims priority of application No. 20170579 (EP), filed on Apr. 21, 2020.
Prior Publication US 2023/0089144 A1, Mar. 23, 2023
Int. Cl. C07C 7/12 (2006.01); C07C 15/08 (2006.01); B01D 69/14 (2006.01); B01D 61/38 (2006.01); B01D 15/18 (2006.01)
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
OG exemplary drawing
 
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.