Mobil Oil Corporation

Exxonmobil Oil Corporation

Mobile Oil Corporation

Paul G Rodewald, Jr

Clarence D Chang

David H Olson

Werner O Haag

Catherine S Chen

Ernest W Valyocsik

David S Shihabi

Thomas F Degnan

Sharon B McCullen

Cynthia T-w Chu

Nai Y Chen

Ralph M Dessau

William E Garwood

Darrell D Whitehurst

Paul B Weisz

Stephen A Butter

John D Lutner

A zeolite catalyst suitable for use in shape-selective hydrocarbon conversion processes. The catalyst is modified by incorporation therein of a hydrogenation-dehydrogenation functional metal, followed by gradient selectivation with an organosilicon compound under conversion conditions, wherein the gradient selectivation conditions are characterized by a progressive temperature gradient. The use of a progressive temperature gradient during the in situ selectivation procedure unexpectedly yields a catalyst in which the hydrogenation-dehydrogenation function is stabilized, thereby enabling long duration hydrocarbon conversion processes with low by-product make.

Zeolite catalysts having stabilized hydrogenation-dehydrogenation function

A method of preparing a modified catalytic molecular sieve for enhanced shape selective hydrocarbon conversions in which a catalytic molecular sieve is modified by being exposed to at least one ex situ selectivation sequence, each sequence including an impregnation of the molecular sieve with a selectivating agent in an aqueous emulsion and a subsequent calcination of the impregnated molecular sieve. The selectivating agent compositions for the ex situ selectivation method are also described, including the selectivating agents, the surfactants, and the aqueous components. Also, a method for moderate steaming of the ex situ selectivated molecular sieve. Also a method for in situ trim-selectivating the ex situ selectivated catalytic molecular sieve. Also described is the modified catalytic molecular sieve modified by this method. Also described is a process for shape selective hydrocarbon conversion comprising contacting a hydrocarbon feedstream under conversion conditions with the modified catalytic molecular sieve.

Method of preparation of ex situ selectivated zeolite catalysts for

A process and catalyst for Shape Selective Hydrocarbon Conversions such as the regioselective disproportionation of toluene to para-xylene wherein hydrocarbon to be converted is passed over a catalytic molecular sieve which is trim selectivated with a reaction stream comprising toluene and a silicon-containing high efficiency p-xylene selectivating agent under toluene conversion conditions. The toluene disproportionation process attains a single-pass para-xylene product over 95% coupled with a toluene conversion of at least 15%. The present invention also includes the highly para-selective catalyst which results from the treatment of a catalytic molecular sieve with a high efficiency p-xylene selectivating agent under the recited conditions.

Regioselective methylation of toluene to para-xylene

There is provided a zeolite, such as ZSM-5, which is functionalized with at least one organosiliceous group of the formula, SiR.sub.n (OX).sub.4-n, where R is at least one hydrocarbyl group, n is 1 or 2 and X is Si or H. There is also provided a method for functionalizing a zeolite by treatment with a silicone compound, such as hexamethyldisiloxane, under vapor phase conditions. This contacting may take place in the presence of hydrogen and an organic carrier. The functionalized zeolites may provide a catalyst which is both highly active and highly selective for converting aromatic hydrocarbons, especially alkylbenzene compounds, to products comprising the para-isomer of dialkylbenzenes. The disproportionation of toluene is an example of such a reaction.

Zeolite functionalized with organosiliceous groups

A catalytic molecular sieve which has been preselectivated by agglomerating with an organosilicon compound. The invention also includes a method for agglomeration-preselectivation and the shape selective catalyst which results from the agglomeration preselectivation.

Extrusion-modified molecular sieve

There is provided a method for selectivating a zeolite, such as ZSM-5 which may result in functionalization of the zeolite with at least one organosiliceous group of the formula, SiR.sub.n (OX).sub.4-n, where R is at least one hydrocarbyl group, n is 1 or 2 and X is Si or H. This selectivation method involves vapor phase treatment of a zeolite with an organosilicon compound having at least 2 silicon atoms. This organosilicon compound may be a silicone compound, such as hexamethyldisiloxane, or a silane compound such as hexamethyldisilane. This contacting may take place in the presence of hydrogen and an organic carrier. The functionalized zeolites may provide a catalyst which is both highly active and highly selective for converting aromatic hydrocarbons, especially alkylbenzene compounds, to products comprising the para-isomer of dialkylbenzenes. The disproportionation of toluene is an example of such a reaction.

Selectivating zeolites with organosiliceous agents

A method for the selective disproportionation of a substituted aromatic compound wherein the aromatic compound is passed over a catalytic molecular sieve which has been pre-selectivated with a silicon deposit and then subsequently treated with a silicon-containing, high efficiency p-xylene selectivating agent at conversion conditions. The present invention attains para-xylene product over 95% at a toluene conversion of at least 20%. The present invention also includes the highly para-selective catalyst which results from the pre-selectivation and subsequent treatment of a catalytic molecular sieve with a high efficiency p-xylene selectivating agent under the recited conditions.

Regioselective production of para-dialkyl benzenes

A process for alkylating an isoparaffin with an olefin in the presence of a catalyst comprising HF, BF.sub.3, and a hydroxylic promoter wherein the total acid dosage as defined herein is less than about 1 weight percent of the total hydrocarbon reactants and the molar ratio of BF.sub.3 to the sum of the moles of HF and hydroxylic promoter is greater than zero and less than about 1.

Isoparaffin/olefin alkylation with minimal acid inventory

A process for a shape selective hydrocarbon conversion such as toluene disproportionation involves contacting a reaction stream under conversion conditions with a catalytic molecular sieve which has been pre-selectivated and concurrently activated by contact with a substantially aqueous solution of an organosilicon compound. The invention also includes a method for concurrently preselectivating and activating a catalyst and the shape selectivated, activated catalyst which results from this method.

Shape selective hydrocarbon conversion over pre-selectivated, activated

A process for a shape selective hydrocarbon conversion such as toluene disproportionation, involves contacting a reaction stream under conversion conditions with a catalytic molecular sieve which has been preselectivated by agglomerating with an organosilicon compound. The invention also includes a method for agglomeration-preselectivation and the shape selective catalyst which results from the agglomeration preselectivation.

Shape selective conversion of hydrocarbons over extrusion-modified

Processes for converting a wide variety of aromatic hydrocarbons, such as polyalkylaromatics, into commercially useful para-substituted aromatics such as para-xylene are disclosed. The aromatic hydrocarbon feed stream is first partially converted into toluene which is then subjected to a highly para-selective methylation process. The present invention therefore provides novel processes and catalysts for increasing the para-selectivity in the selective production of para-substituted aromatic compounds. From the description provided herein, those skilled in the art will appreciate that the catalysts and processes of the present invention provide greater para-selectivity at conversion rates unattained by previously known methods.

Process for the regioselective conversion of aromatics to

The invention relates to the treatment of crystals of ZSM-5 with mineral acid to produce ZSM-5 crystals which have an acid activity associated with the pores and channels thereof, the shape selective portion of the crystal, which is greater than the acid activity of the non-shape selective portion of the crystal or the surface of the ZSM-5 crystal, and the effect of the treated zeolite, as a catalyst component, in catalytic hydrocarbon conversions.

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Rocky Hill, NJ, United States of America

Paul G Rodewald, Jr