Process for the production of para-xylene using toluene feeds and pressure swing adsorption

US6689929B2 · kind B2 · utility

Assignee

• BP CORPORATION NORTH AMERICA INC. · US

Inventors

• Bryce Williams · Frankfurt am Main, DE
• Jeffrey T. Miller · Naperville, US
• Ruth Ann Doyle · Oswego, US
• Giorgio Zoia · Los Angeles, US

Key dates

• Filing date: Jul 10, 2001
• Grant date: Feb 10, 2004
• Expiry date: Nov 9, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C7/14
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A pressure swing adsorption process to separate para-xylene and ethylbenzene from a C8 aromatics stream produced by toluene conversion uses a para-selective adsorbent, preferably a non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the pX and EB giving a pX/EB-rich effluent. A stream of non-adsorbed mX and oX may be obtained before desorbing pX and EB.