Chevron Chemical Company LLC

Chevron Research & Technology Company

Chevron U.s.a. Inc.

Other

Idemitsu Kosan Company, Limited

Chevron Research Company

Chevron Phillips Chemical Company LP

Chevron Limited

Chevron Research & Technology Co., a Div. of Chevron U.s.a. Inc.

Robert A Innes

Dennis L Holtermann

Stacey Ian Zones

James Nathan Ziemer

Donald S Santilli

Bernard F Mulaskey

Theresa A Pecoraro

John V Heyse

William James Cannella

Daniel P Hagewiesche

Robert L Hise

Steven E Trumbull

David C Kramer

Gerald J Nacamuli

Gale L Hubred

Steven Clay Moore

Michio Sugimoto

Tetsuya Fukunaga

Randall J Harris

Paul F Bryan

Alan G Kunze

Stacy I Zones

Arnold J Gloyn

Stephen LeRoy Bursch

A digitally controlled platform for precise celestial tracking of astronomical telescopes, generally those having an independent pointing mechanism. A movable stage carrying the telescope is moved relative to a base by three digitally controlled actuators each of which determines the distance between a point fixed in the base and a point fixed stage. The base and stage otherwise are connected by a mechanism that holds a single point fixed in the base in coincidence with a single point fixed in the stage. It functions without approximation at any digitally specified latitude and longitude, enabling astrophotography with alt/azimuth mounted telescopes and diurnal tracking through the zenith. The digital controller may be a personal computer laptop running a multitasking operating system linked to the platform electronics by a Universal Serial Bus cable. Novel software design allows precise tracking, control, and calibration in spite of operating system and Universal Serial Bus latency.

Digital tracking platform for telescopes

Carburization and metal-dusting while hydrodealkylating a hydrodealkylatable hydrocarbon are reduced even in the substantial absence of added sulfur.

Hydrodealkylation processes

Disclosed is a method for reforming hydrocarbons comprising contacting the hydrocarbons with a catalyst in a reactor system of improved resistance to carburization and metal dusting under conditions of low sulfur.

Apparatus for hydrocarbon processing

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

There are herein disclosed an L-type zeolite catalyst which is obtainable by supporting a platinum component, one or more halogen components and one or more metal components selected from the group Ib of the periodic table on an L-type zeolite, the support amount of one or more metal components selected from the group Ib being in the range of 0.001 to 3% by weight based on the total weight of the catalyst in terms of the metal, a molar ratio of one or more metal components selected from the group Ib/platinum being in the range of 0.01 to 1; and a method for producing aromatic hydrocarbons or a gasoline having a high octane number which comprises the step of bringing one or more fractions selected from a C6 fraction, a C7 fraction, and a C8.sup.+ fraction into contact with this catalyst. According to the present invention, there are provided a catalyst containing an L-type zeolite as a carrier which is desirable as a catalyst for the production of aromatic hydrocarbons or a gasoline having a high octane number and which can inhibit a cracking activity and the formation of coke and can improve an aromatic selectivity and a liquid yield.

L-type zeolite catalyst

A crystalline zeolite SSZ-25 is prepared using an adamantane quaternary ammonium ion as a template.

Isomerization process using zeolite SSZ-25

A process for regenerating a coke contaminated reforming catalyst comprising platinum on a molecular sieve, said process consisting essentially of contacting said catalyst with a halogen-free oxygen-containing gas at a temperature of less than 780.degree. F. for a sufficient period of time such that the aromatization activity is restored to within 20.degree. F. of the activity said catalyst possessed at the start of the previous run cycle.

Low temperature regeneration of coke deactivated reforming catalysts

Low-sulfur reforming process

A catalytic reforming process is disclosed using a catalyst containing a Group VIII metal, low amounts of bismuth, and a zeolite L. The catalyst is a non-acidic, monofunctional reforming catalyst. Preferably, the catalyst contains one or more halogens. Preferably, the feed includes C.sub.8 hydrocarbons. The addition of small amounts of bismuth increase or substantially maintain catalyst stability. Unexpectedly low dealkylation rates are achieved using the catalyst while reforming to produce aromatics, especially to produce xylenes such as paraxylene.

Reforming process using monofunctional catalyst containing bismuth

Carburization and metal-dusting while hydrodealkylating a hydrodealkylatable hydrocarbon are reduced even in the substantial absence of sulfur.

A high temperature treatment process is disclosed for increasing conversion and reducing the fouling rate of reforming catalysts. The process comprises reducing the catalyst in a reducing gas atmosphere at a temperature below 1025.degree. F. and then treating the reduced catalyst at a temperature of from 1025.degree. F. to 1275.degree. F. in an inert gas atmosphere.

High temperature treatment of reforming catalyst with an inert gas

Alkylation process using zeolite SSZ-25

A pretreatment process is disclosed for increasing conversion and reducing the fouling rate of reforming catalysts wherein the catalyst is pretreated at a temperature from 1025.degree. F. to 1275.degree. F. in a reducing atmosphere prior to contacting the catalyst with a hydrocarbon feed in the presence of hydrogen.

Pretreatment method for increasing conversion of reforming catalyst

Provided is a process for catalytic reforming a hydrocarbon feedstock containing at least 20 ppbw sulfur. The process comprises passing the hydrocarbon feedstock through at least two serialy connected reforming zones, with each zone containing a highly sulfur sensitive reforming catalyst. The catalyst in the first reforming zone is more frequently regenerated than the catalyst in the second reforming zone. The result is a highly efficient and simplified process for reforming a sulfur contaminated hydrocarbon feedstock. The process basically employs a minor portion of the highly sulfur sensitive reforming catalyst as both the reforming catalyst and a sulfur removal agent.

Growing community of inventors

San Rafael, CA, United States of America

Robert A Innes