Exxonmobil Chemical Patents Inc.

Xiaobo Zheng

Robert G Tinger

Mark Paul Hagemeister

Michel Molinier

Timothy Paul Bender

Larry Lee Iaccino

John Di-Yi Ou

Hari Nair

Chunshe J Cao

Todd E Detjen

Jerome Pigourier

Kevin J Knob

Dennis J Stanley

Jacques Rault

Thierry Leflour

Celia Fernandez

Stephane Claudel

Terri S Vander Pol

James Richardson Lattner

Kenneth Ray Clem

Jane C Cheng

Mobae Afeworki

Neeraj Sangar

Kathleen M Keville

Lorenzo C DeCaul

John D Y Ou

Isabelle Prevost

Juan D Henao

Lu Han

S Mark Davis

Jeffrey L Andrews

Jon E R Stanat

Jon Edmond Randolph Stanat

Isabell Prevost

The invention relates to treating a molecular sieve prepared by at least one in situ selectivation sequence wherein graphitic coke is adhered to said molecular sieve, which is useful in a toluene disproportionation process.

In-situ trim coke selectivation of toluene disproportionation catalyst

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

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

A 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 catalyst system comprises a first catalyst bed and a second catalyst bed. The first catalyst bed comprises a first zeolite and a rhenium hydrogenation component. The first zeolite has a constraint index from 1 to 12, an average crystal size from 0.1 to 1 micron and has been selectivated to have an ortho-xylene sorption time of greater than 1200 minutes based on its capacity to sorb 30% of the equilibrium capacity of ortho-xylene at 120&#xb0; C. and an ortho-xylene partial pressure of 4.5&#xb1;0.8 mm of mercury. The second catalyst bed comprises a second zeolite and a rhenium hydrogenation component. The second zeolite has a constraint index ranging from 1 to 12 and an average crystal size of less than 0.1 micron.

Method and catalyst system for the production of para-xylene

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 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

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.

Production of para-xylene

In a hydrocarbon upgrading process, a hydrocarbon feed is treated in at least one of a steam cracker, catalytic cracker, coker, hydrocracker, and reformer under suitable conditions to produce a first stream comprising olefinic and aromatic hydrocarbons. A second stream composed mainly of C+ olefinic and aromatic hydrocarbons is recovered from the first stream and is fed together with a methylating agent to a reaction zone containing a catalyst under reaction conditions including a temperature of about 450&#xb0; C. to about 700&#xb0; C., such that aromatics components in the second stream undergo dealkylation, transalkylation and/or methylation and aliphatic components undergo cracking and aromatization to produce a third stream having an increased xylene content compared with said second stream and a C&#x2212; olefin by-product. The C&#x2212; olefin by-product is recovered and para-xylene is removed from at least part of said third stream.

Process for the production of xylenes and light olefins

The invention relates to the production of paraxylene by an alkylation process that also produces oxygenates. The process is controlled to utilize recycle to minimize said oxygenates.

Alkylation process

In a process for the regeneration of a coked metal-containing catalyst, the coked catalyst is contacted in a regeneration zone with an atmosphere which contains carbon dioxide and carbon monoxide at a temperature of at least 400&#xb0; C.

Regeneration of metal-containing catalysts

In a process for the production of para-xylene, methanol is preheated to a first temperature, an aromatic feedstock comprising toluene and/or benzene is preheated to a second temperature and the preheated methanol and aromatic feedstocks are fed to a reactor at a first methanol to aromatic feedstock molar ratio. The preheated aromatic feedstock is contacted with the preheated methanol under alkylation conditions in the reactor in the presence of a catalyst so that the methanol reacts with the aromatic feedstock to produce an effluent comprising para-xylene. During the reaction, a temperature is measured within the reactor and is compared with a predetermined optimal temperature. The methanol to aromatic feedstock molar ratio is then adjusted in a manner to reduce any difference between the measured and predetermined optimal temperatures in the reactor.

Production of para-xylene by the methylation of benzene and/or toluene

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Houston, TX, United States of America

Xiaobo Zheng