Bp Corporation North America Inc.

Ruth Ann Doyle

Jeffrey T Miller

Bryce A Williams

Giorgio Zoia

Allen I Feinstein

Scott Roberts

Richard Wilsak

Calvin T Chew

Kevin A Kunz

Disclosed herein is an improved method for making and obtaining para-xylene from a mixture of xylene isomers, and various embodiments of the method. The method generally includes contacting a mixture comprising xylene isomers and ethylbenzene with a para-xylene selective adsorbent to obtain a para-xylene depleted raffinate, and a desorption effluent comprising a para-xylene enriched product. The method also includes isomerizing the para-xylene depleted raffinate. The contacting step is carried out in a manner such that the raffinate need not be pressurized prior to isomerization, thus advantageously obviating expensive compression steps.

Method of obtaining para-xylene

Adsorbent compositions for vapor-phase adsorption processes, which are selective for para-xylene. Such compositions can be used in gas-phase adsorption processes for the separation of para-xylene or the separation of para-xylene and ethylbenzene from mixed xylenes or a Caromatic mixture, respectively. The adsorbent compositions generally comprise materials of a molecular sieve material and a binder, wherein the adsorbent composition has a macropore volume of at least about 0.20 cc/g and a mesopore volume of less than about 0.20 cc/g.

Para-xylene selective adsorbent compositions and methods

A pressure swing adsorption process to separate para-xylene and ethylbenzene from a C 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.

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

A pressure swing adsorption process to separate para-xylene and ethylbenzene from C aromatics 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 para-xylene and ethylbenzene, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the para-xylene and ethylbenzene. The process effluent is rich in para-xylene and ethylbenzene. A stream of non-adsorbed meta-xylene and ortho-xylene may be obtained prior to desorption of para-xylene and ethylbenzene.

Pressure swing adsorption process for separating para-xylene and ethylbenzene from mixed C8 aromatics

A pressure swing adsorption process to separate para-xylene and ethylbenzene from C aromatics which uses a para-selective, non-acidic, medium pore molecular sieve of the MFI structure type and is operated isothermally in the vapor phase at elevated temperatures and pressures is integrated with crystallization to produce para-xylene product. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, the feed is stopped, and lowering the partial pressure desorbs the pX and EB. The process effluent, which is rich in pX and EB, is crystallized to obtain para-xylene product.

Para-xylene production process integrating pressure swing adsorption and crystallization

A pressure swing adsorption process to separate para-xylene and ethylbenzene from C aromatics which uses a para-selective, non-acidic, medium pore molecular sieve of the MFI structure type and is operated isothermally in the vapor phase at elevated temperatures and pressures is integrated with simulated moving bed adsorption (SiMBAC) to produce para-xylene product. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, the feed is stopped, and lowering the partial pressure desorbs the pX and EB. The process effluent, which is rich in pX and EB, is subjected to SiMBAC to obtain para-xylene product.

Process for production of para-xylene incorporating pressure swing adsorption and simulated moving bed adsorption

A catalyst system suitable for the isomerization of a xylene and conversion of ethylbenzene in a feed containing xylene and ethylbenzene comprising a first catalyst having activity for the conversion of ethylbenzene, a second catalyst having hydrogenation activity and a third catalyst having activity for the isomerization of a xylene where the second catalyst is located in the system between the first and third catalysts relative to a flow of feed material through the catalyst system.

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Oswego, IL, United States of America

Ruth Ann Doyle