Chevron Chemical Company LLC

Other

Chevron Research Company

Chevron Research & Technology Company

Chevron Limited

Gerald J Nacamuli

Roger F Vogel

Stacey Ian Zones

Robert A Innes

Arnold J Gloyn

Bruce J Thom

Charles R Wilson

Eric P Weber

Donald A Hickson

Paul M Spindler

Scott Gordon Morrison

Stuart R MacPherson

Paul I Hodgen

N J Haritatos

Nhu Q Dao

Gary A Ash

Richard Wolpert

A process is set forth for reacting impure toluene to obtain benzene, toluene and a para-rich xylene stream, which are substantially free of close-boiling non-aromatics. The impure toluene comprises at least 70 wt % toluene and between about 0.2 wt % and about 5 wt % close-boiling non-aromatics. The process may also comprise aromatizing a naphtha over a non-acidic catalyst. The impure toluene from the aromatization step is passed over an acidic intermediate pore zeolite to produce a para-rich xylene stream and chemically pure benzene.

Manufacture of high purity benzene and para-rich xylenes by combining aromatization and selective disproportionation of impure toluene

This process relates to reforming a full-boiling range hydrocarbon feed in two parallel stages while maximizing the catalyst life of the heavy cut reformer and/or reducing the complexity of the plant by preferentially sending the higher purity Aromax.RTM. hydrogen to the heavy cut reformer.

Process for production of aromatics in parallel reformers with an

A new process for the hydrodealkylation of ethylbenzene and the isomerization of xylenes at low pressure and at a low hydrogen to ethylbenzene mole ratio as well as a low hydrogen to hydrocarbon feed mole ratio using a catalyst comprising (a) HZSM-5 having a particle size less than 1.0 microns, and (b) a Group VIII metal such as platinum.

Low pressure hydrodealkylation of ethylbenzene and xylene isomerization

A full boiling hydrocarbon feed is reformed to enhance para-xylene and benzene yields. First, the hydrocarbon feed is separated into a C.sub.5- cut, a C.sub.6 -C.sub.7 cut, and a C.sub.8+ cut. The C.sub.6 -C.sub.7 cut has less than 5 lv. % of C.sub.8+ hydrocarbon, and the C.sub.8+ cut has less than 10 lv. % of C.sub.7- hydrocarbon. The C.sub.6 -C.sub.7 cut is subjected to catalytic aromatization at elevated temperatures in a first reformer in the presence of hydrogen and using a non-acidic catalyst comprising at least one Group VIII metal and a non-acidic zeolite support to produce a first reformate stream; and the C.sub.8+ cut is subjected to catalytic aromatization at elevated temperatures in a second reformer in the presence of hydrogen and using an acidic catalyst comprising at least one Group VIII metal and a metallic oxide support to produce a second reformate stream. Less than 20 wt. % of the total amount of C.sub.8 aromatics produced in the first and second reformer is ethylbenzene, and more than 20 wt. % of the total amount of xylenes produced in the first and second reformer are para-xylenes.

Split-feed two-stage parallel aromatization for maximum para-xylene yield

A process is provided for producing high purity benzene and high purity paraxylene from a hydrocarbon feed. In one aspect, the process comprises: (a) reforming a hydrocarbon feed using either a monofunctional catalyst or a bifunctional catalyst to provide one or more reformate streams; (b) fractionating the reformate stream to provide a toluene stream, a benzene stream, and a xylene stream; (c) subjecting the toluene stream to disproportionation; (d) purifying the benzene stream by extraction followed by distillation to provide a high purity benzene product; and (e) purifying the xylene stream by simulated moving bed countercurrent adsorption followed by crystallization to provide a high purity paraxylene product.

Process for converting hydrocarbon feed to high purity benzene and high

A hydrocarbon feed is reformed to enhance para-xylene yield and to minimize ethylbenzene production. The hydrocarbon feed is subjected to catalytic aromatization at elevated temperatures in the presence of hydrogen, using a non-acidic catalyst having at least one Group VIII metal on a non-acidic zeolite support, to produce a reformate stream containing ethylbenzene and xylenes in which the para-xylene content of the xylene fraction is less than equilibrium. Then, at least some of the reformate is reacted at elevated temperatures in the presence of hydrogen, using an intermediate pore size zeolitic catalyst having a modifier in the absence of a Group VIII metal, to isomerize the non-equilibrium xylene fraction. The modifier can be magnesium, calcium, barium, or phosphorus. At least 20 wt. % of the ethylbenzene in the reformate is converted by hydrodealkylation.

Two-stage reforming process that enhances para-xylene yield and

A gas phase, aromatics transalkylation process that comprises contacting a stream containing aromatic hydrocarbons with a catalyst comprising a zeolite selected from the group consisting of SSZ-26, Al-SSZ-33, CIT-1, SSZ-35, and SSZ-44 in the presence of added hydrogen and in the gas phase, to produce transalkylated product. The aromatics stream comprises one or more aromatic hydrocarbons, one of the hydrocarbons having at least one alkyl group attached thereto, the alkyl group comprising a C1, C2, C3 or C4 hydrocarbyl group. A preferred aromatics transalkylation process comprises contacting toluene or benzene or a mixture thereof with a stream containing trimethylbenzene in the presence of added hydrogen. The catalyst preferably contains a mild hydrogenation metal, such as nickel or palladium.

Aromatics and toluene/trimethylbenzene gas phase transalkylation

A new process for the hydrodealkylation of ethylbenzene and the isomerization of xylenes at low pressure and at a low hydrogen to ethylbenzene mole ratio as well as a low hydrogen to hydrocarbon feed mole ratio using a catalyst comprising (a) HZSM-5 having a particle size less than 1.0 microns, (b) a Group VIII metal such as platinum, and (c) an additional element such as magnesium.

A process for the alkylation or transalkylation of an aromatic hydrocarbon which comprises contacting the aromatic hydrocarbon with a C.sub.2 to C.sub.4 olefin alkylating agent or a polyalkyl aromatic hydrocarbon transalkylating agent, under at least partial liquid phase conditions, and in the presence of a catalyst comprising zeolite beta.

Liquid phase alkylation or transalkylation process using zeolite beta

A process for isomerizing xylenes containing ethylbenzene to obtain near equilibrium amounts of paraxylene and to convert the ethylbenzene to hydrocarbons readily removable from the xylenes. The isomerization reaction uses a ZSM-5 type catalyst with 0.05 to 1.5 percent of an added metal such as zinc, cadmium, or barium. The isomerization is carried out in the absence of added hydrogen at low pressure, preferably between about 0 and 200 psig. Relatively low xylene losses are achieved even at high ethylbenzene conversion levels.

Growing community of inventors

Mill Valley, CA, United States of America

Gerald J Nacamuli