Exxonmobil Chemical Patents Inc.

Exxonmobil Chemicals Patents, Inc.

Timothy Paul Bender

Robert G Tinger

Dana Lynn Pilliod

John Roger Porter

Xiaobo Zheng

Jeffrey L Andrews

Mark Paul Hagemeister

Michel Molinier

Dennis J Stanley

George J Wagner

James Richardson Lattner

Stephen Harold Brown

Gaurav Agrawal

Larry Lee Iaccino

Jeevan Sahib Abichandani

Kathleen M Keville

Michael Salciccioli

Robert David Strack

Glenn Allen Heeter

Michael W Weber

Lu Han

Christopher Gordon Smalley

Rathna P Davuluri

Todd E Detjen

Jon Edmond Randolph Stanat

Glenn C Wood

Allen Scott Gawlik

Masaaki Sugita

Justin M Ellrich

John W Rebeck

Chong Jhoo Wang

A process is provided for producing xylene by transalkylation including introducing sulfur into a reactor containing a catalyst system prior to first introduction of hydrocarbon feedstock into the reactor; introducing hydrocarbon feedstock into the reactor upon the concentration of sulfur downstream of the catalyst system meeting a predetermined sulfur breakthrough concentration; continuing sulfur introduction for a period of time after first introducing hydrocarbon feedstock into the reactor; reducing the concentration of sulfur introduced upon &#x394;T decreasing to or below a predetermined sulfur reduction threshold; and discontinuing sulfur introduction upon &#x394;T decreasing to or below a predetermined sulfur shutoff threshold.

Sulfiding process for aromatic transalkylations

The present invention relates to an improved extractive distillation process for recovering aromatic hydrocarbons from non-aromatic hydrocarbons in naphtha streams containing heavy hydrocarbon contaminants wherein each contaminant is characterized as having a boiling point in the range of between that of the separated non-aromatic hydrocarbons and the extractive distillation solvent utilized to recover and purify the aromatic hydrocarbons.

Process and apparatus for recovering aromatic hydrocarbons

A process for producing para-xylene (PX) comprises supplying a hydrocarbon feed comprising xylenes and ethylbenzene (EB) to a PX recovery unit, where a PX-rich stream and at least one PX-depleted stream are recovered from the feed. The PX-depleted stream is then separated into an EB-rich stream and an EB-depleted stream in a divided wall column. The EB-depleted stream is then isomerized under at least partial liquid phase conditions to produce a first isomerized stream having a higher PX concentration than the PX-depleted stream, and the EB-rich stream is isomerized under at least partial vapor phase conditions to produce a second isomerized stream having a higher PX concentration than the PX-depleted stream. The first and second isomerized streams are then recycled to the PX recovery unit to recover additional PX and the process is repeated to define a so-called xylene isomerization loop.

Process and apparatus for the production of para-xylene

A simulated moving bed process using dual, parallel rotary valves configured or plumbed to be operated independently in which the step times of the rotary valves are staggered. In embodiments, the second rotary valve is programmed to step about halfway through the step time of the first rotary valve. Staggering the step time of the parallel rotary valves, rather than utilizing simultaneous stepping, results in increased net composite paraxylene concentration of the extract stream, allowing for increased capacity of the simulated moving bed process and/or reduced energy consumption.

Xylene separation process and apparatus

A process for producing paraxylene is provided. The process includes separating a first mixture of Caromatic hydrocarbons in a simulated moving bed apparatus using a desorbent to produce (i) an extract comprising &#x2267;50.0 wt % of the paraxylene in the first mixture; (ii) a desorbent-rich raffinate comprising &#x2267;75 wt % of the desorbent withdrawn, and (iii) an desorbent-lean raffinate comprising &#x2266;25 wt % of the desorbent withdrawn in the desorbent-rich and desorbent-lean raffinates. The desorbent-lean raffinate can then, without an intervening separation step, be passed to a refinery process or a vapor phase isomerization reaction to produce an effluent comprising paraxylene in a greater concentration than the desorbent-lean raffinate. The desorbent-rich raffinate can be passed to a liquid phase isomerization reaction to produce an effluent comprising paraxylene in a greater concentration than the desorbent-rich raffinate.

Paraxylene separation process

In a process for producing para-xylene, a feed comprising a mixture of xylene isomers, olefinic unsaturated contaminants and oxygenate contaminants is supplied to a para-xylene recovery unit to recover para-xylene and produce a para-xylene depleted residual stream. The para-xylene depleted residual stream is then contacted with a xylene isomerization catalyst in a xylene isomerization zone under liquid phase conditions effective to isomerize xylenes and produce an isomerized product having a higher para-xylene content than the para-xylene depleted residual stream. The isomerized product is then recycled to the para-xylene recovery unit. At least one of the feed, the para-xylene depleted residual stream and the isomerized product is contacted with a solid acid catalyst in a treatment zone under conditions effective to reduce the level of olefinic unsaturated contaminants and oxygenate contaminants therein and produce a treated stream.

Production of para-xylene

The invention relates to a transalkylation system to convert feedstreams containing benzene and/or toluene (C7&#x2212; aromatic hydrocarbons) and feedstreams containing C9+ aromatic hydrocarbons into a product stream comprising xylenes.

Transalkylation system

A process is described for separating paraxylene from a multicomponent fluid mixture of C8 aromatics, and more particularly to a process for separating paraxylene from such a fluid mixture by means of adsorption apparatus, such as moving-bed or simulated moving-bed adsorption apparatus. A process is also described for making paraxylene by making a mixture of C8 aromatics and separating paraxylene from the mixture by means of a simulated moving-bed adsorption apparatus.

Xylene separation process

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

The invention is directed to a process of contacting at least one zeolite, selected from the MWW family of zeolites, with an aromatic hydrocarbon stream in a system comprising at least one reactor containing the at least one zeolite, wherein the conditions in the reactor are adjusted in response to at least one measurement of the system so as to preferentially increase oxygenate removal or to preferentially increase olefin removal.

Treatment of aromatic hydrocarbon stream

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.

The invention is a process for producing paraxylene, benzene and/or toluene is alkylated with methanol in the presence of a catalyst under conditions effective to convert said benzene and/or toluene to xylene and produce a product stream containing water, xylene and one or more phenolic impurities. The said product stream is separated into a water-rich stream and a xylene-rich stream containing one or more phenolic impurities and at least a portion of the xylene-rich stream is contacted with an aqueous solution of a base under conditions to remove at least some of the phenolic impurities from the xylene-rich stream portion.

The process relates to the use of any naphtha-range stream containing a portion of C8+ aromatics combined with benzene, toluene, and other non-aromatics in the same boiling range to produce toluene. By feeding the A8+ containing stream to a dealkylation/transalkylation/cracking reactor to increase the concentration of toluene in the stream, a more suitable feedstock for the methylation reaction can be produced. This stream can be obtained from a variety of sources, including the pygas stream from a steam cracker, 'cat naphtha' from a fluid catalytic cracker, or the heavier portion of reformate.

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Houston, TX, United States of America

Timothy Paul Bender