Exxonmobil Chemical Patents Inc.

Delphi Technologies, Inc.

Exxonmobil Chemicals Patents, Inc.

Michel Molinier

Jeffrey L Andrews

Robert G Tinger

Michael A Risch

Hari Nair

Chunshe J Cao

Dennis J Stanley

Scott Jeffrey Weigel

David M Lowe

Anthony F Volpe

John D Y Ou

Jeffrey C Yoder

Doron Levin

John Di-Yi Ou

Michael Salciccioli

Xiaobo Zheng

George J Wagner

Jeevan Sahib Abichandani

Valery Sokolovskii

Paul Podsiadlo

Dana Lynn Pilliod

Timothy Paul Bender

Jerome Pigourier

Kevin J Knob

Meha Rungta

Thierry Leflour

Jacques Rault

Terri S Vander Pol

Stephane Claudel

Celia Fernandez

James Richardson Lattner

Kun Wang

John Scott Buchanan

John Frances Brody

Isabelle Prevost

Mayank Shekhar

Joseph E Gatt

Owen Herman Bailey

Travis Sparks

Jocelyn A Gilcrest

Isabell Prevost

A transalkylation process co-feeds benzene at a relatively high proportion with C9+ aromatics in a feed stream to a transalkylation reactor. At lower proportions (&#x2264;5 wt %) of benzene, ring loss is greater for benzene than toluene and ring loss is increased by increasing the proportion of benzene in the feed stream. When the benzene is co-fed in a proportion sufficiently greater than 5 weight percent of the feed stream, ring loss is unexpectedly reduced.

Transalkylation with reduced ring loss

Methods are provided for activation of catalysts comprising low amounts of a hydrogenation metal, such as low amounts of a Group 8-10 noble metal. The amount of hydrogenation metal on the catalyst can correspond to 0.5 wt % or less (with respect to the weight of the catalyst), or 0.1 wt % or less, or 0.05 wt % or less. Prior to loading a catalyst into a reactor, the corresponding catalyst precursor can be first activated in a hydrogen-containing atmosphere containing 1.0 vppm of CO or less. The thus first-activated catalyst can be transferred to a reactor with optional exposure to oxygen during the transfer, where it can be further activated using a hydrogen-containing atmosphere containing 3.0 vppm of CO or higher, to yield a twice-activated catalyst with high performance. The catalyst can be advantageously a transalkylation catalyst or an isomerization catalyst useful for converting aromatic hydrocarbons.

Activation of low metal content catalyst

A process and related system for producing para-xylene (PX). In an embodiment, the process includes (a) separating a feed stream comprising Caromatic hydrocarbons into a toluene containing stream and a Chydrocarbon containing stream and (b) contacting at least part of the toluene containing stream with a methylating agent in a methylation unit to convert toluene to xylenes and produce a methylated effluent stream. In addition, the process includes (c) recovering PX from the methylated effluent stream in (b) to produce a PX depleted stream and (d) transalkylating the PX depleted stream to produce a transalkylation effluent stream. The transalkylation effluent stream includes a higher concentration of toluene than the PX depleted stream. Further, the process includes (e) converting at least some ethylbenzene (EB) within the Chydrocarbon containing stream into toluene and (f) flowing the toluene converted in (e) to the contacting in (b).

Xylene production processes and systems

Alkyl-demethylation of C2+-hydrocarbyl substituted aromatic hydrocarbons can be utilized to treat one or more of a heavy naphtha reformate stream, a hydrotreated SCN stream, a C8 aromatic hydrocarbon isomerization feed stream, a C9+ aromatic hydrocarbon transalkylation feed stream, and similar hydrocarbon streams to produce additional quantity of xylene products.

Processes for converting aromatic hydrocarbons via alkyl-demethylation

Transalkylation processes for converting aromatic hydrocarbons comprising alkyl-demethylation

Disclosed is a transalkylation process for making an aromatic material between a light aromatic material and a heavier aromatic material in the presence of hydrogen and a transalkylation catalyst comprising a hydrogenation component and a transalkylation component. The process comprises conducting the transalkylation reaction under conditions conducive to reducing the amount of cyclic compounds in the transalkylation reaction mixture in the beginning phase of the operation that is different from the conditions after the beginning phase. The invention is useful, e.g., in transalkylation between toluene and C9+ aromatic feed materials to produce xylenes and/or benzene.

Transalkylation process

A process and catalyst system is disclosed for producing para-xylene from a Chydrocarbon mixture comprising ethylbenzene and at least one xylene isomer other than para-xylene. The process modifies the conventional process by operating with a higher weight hourly space velocity, lower pressure and lower hydrogen partial pressure, which allows production of on-specification benzene product without penalty with respect to ethylbenzene conversion, para-xylene approach to equilibrium or xylene losses. The catalyst system comprises a first catalyst bed comprising a first zeolite having a constraint index from 1 to 12 and an average crystal size from 0.1 to 1 micron and a platinum hydrogenation component, and a second catalyst bed comprising a second zeolite having a constraint index ranging from 1 to 12 and an average crystal size of less than 0.1 micron and a rhenium hydrogenation component.

Method and catalyst system for improving benzene purity in a xylenes isomerization process

In a process for producing para-xylene, at least one feed comprising Caromatic hydrocarbons is supplied to a dividing wall distillation column to separate the feed into a Caromatic hydrocarbon-containing stream, a Caromatic hydrocarbon-containing stream and a Caromatic hydrocarbon-containing stream. At least part of the Caromatic hydrocarbon-containing stream is then supplied to a para-xylene recovery unit to recover para-xylene from the Caromatic hydrocarbon-containing stream and produce a para-xylene depleted stream. The para-xylene depleted stream is contacted with a xylene isomerization catalyst in a xylene isomerization zone under conditions effective to isomerize xylenes in the para-xylene depleted stream and produce an isomerized stream, which is then at least partially recycled to the para-xylene recovery unit.

Aromatics production process

The present invention is an improved process and apparatus for producing para-xylene, particularly with respect to a process that involves the methylation of toluene and/or benzene to selectively produce para-xylene, wherein streams having differing amounts of ethylbenzene are separately treated in the recovery of para-xylene. A first hydrocarbon feed comprising xylenes and ethylbenzene is provided to a first para-xylene adsorption section, and a second hydrocarbon feed comprising xylenes and less EB than the first hydrocarbon feed is provided to a second para-xylene adsorption section. Segregating the feeds with differing ethylbenzene contents increases the overall efficiency of the adsorption of para-xylene by the adsorption units. Efficiency and energy savings may be further improved by subjecting the lower-content ethylbenzene stream to liquid phase isomerization.

Process and apparatus for the production of para-xylene

In a process for producing para-xylene, a feed stream comprising Caromatic hydrocarbons is separated into a toluene-containing stream, a Caromatic hydrocarbon-containing stream and a Caromatic hydrocarbon-containing stream. The toluene-containing stream is contacted with a methylating agent to convert toluene to xylenes and produce a methylated effluent stream. Para-xylene is recovered from the Caromatic hydrocarbon-containing stream and the methylated effluent stream in a para-xylene recovery section to produce a para-xylene depleted stream, which is then contacted with a xylene isomerization catalyst under liquid phase conditions effective to isomerize xylenes in the para-xylene depleted stream and produce an isomerized stream. The C-containing stream with a transalkylation catalyst under conditions effective to convert C-aromatics to C-aromatics and produce a transalkylated stream, which is recycled together with the isomerized stream to the para-xylene recovery section.

Apparatus for the production of xylenes

In a process for producing para-xylene, a toluene-containing stream is contacted with a methylating agent under conditions effective to convert toluene to xylenes and produce a methylated effluent stream. Para-xylene is recovered from the methylated effluent stream to produce a para-xylene depleted stream and part of the para-xylene depleted stream is contacted with a xylene isomerization catalyst under liquid phase isomerization conditions effective to produce a first isomerized stream, while part of the para-xylene depleted stream is contacted with a xylene isomerization catalyst under vapor phase isomerization conditions effective to produce a second isomerized stream. The first and second isomerized streams are then recycled to the para-xylene recovery step.

Process for the production of xylenes

In a process for producing para-xylene, a feed stream comprising Caromatic hydrocarbons is separated into a Caromatic hydrocarbon-containing stream, a Caromatic hydrocarbon-containing stream, and a Caromatic hydrocarbon-containing stream. The Caromatic hydrocarbon-containing stream is contacted with a methylating agent to convert toluene to xylenes and produce a methylated effluent stream. Ethylbenzene is removed from the Caromatic hydrocarbon-containing stream, para-xylene is recovered from the ethylbenzene-depleted Caromatic hydrocarbon-containing stream and the methylated effluent stream in a para-xylene recovery section to produce a para-xylene depleted stream, which is then contacted with a xylene isomerization catalyst under liquid phase conditions effective to isomerize xylenes in the para-xylene depleted stream and produce an isomerized stream. The C-containing stream with a transalkylation catalyst under conditions effective to convert C-aromatics to C-aromatics and produce a transalkylated stream, which is recycled together with the isomerized stream to the para-xylene recovery section.

Growing community of inventors

Houston, TX, United States of America

Michel Molinier