Exxon Research and Engineering Company

Chang J Kim

Lawrence L Murrell

Dane C Grenoble

Guido Sartori

Michael T Melchior

Warren A Thaler

Rocco A Fiato

David William Savage

Dan A Farcasiu

George E Milliman

George R Chludzinski

A multi-stage catalyst system is disclosed for the production of waxes in a Fischer-Tropsch process while producing relatively low quantities of methane. A first catalyst converts CO and H.sub.2 into olefins, while a second catalyst converts the olefin, additional hydrogen and CO into higher molecular weight paraffin.

Multi-stage Fischer-Tropsch process

Methane production in catalytic Fischer-Tropsch hydrocarbon synthesis reactions is reduced by adding olefins to the H.sub.2 and CO feed mixture. Alpha olefins of ten carbon atoms or less are particularly preferred.

Reducing methane production in Fischer-Tropsch reactions

Acid catalysts comprising a catalytic metal oxide component wherein said metal is selected from the group consisting essentially of (a) tungsten, niobium and mixtures thereof and (b) mixtures of (a) with tantalum, hafnium, chromium, titanium, zirconium and mixtures thereof, supported on a silica-containing inorganic refractory metal oxide support support wherein the silica content thereof is less than 50 wt. % of the total support, said catalyst being steamed prior to use at a temperature at least 600.degree. C. In a preferred embodiment, the support will comprise a mixture of silica and the .gamma.-alumina wherein the silica content is less than 25 wt. % thereof.

Transition metal oxide acid catalysts

Hydrocarbons are cracked by contacting, in a cracking zone and at elevated temperature, a hydrocarbon feed with an acid catalyst comprising at least a catalytic metal oxide component wherein said metal is selected from the group consisting essentially of (a) tungsten, niobium and mixtures thereof and (b) mixtures of (a) with tantalum, hafnium, chromium, titanium, zirconium and mixtures thereof, and wherein said catalytic metal oxide component is supported on a silica-containing inorganic refractory metal oxide support the silica content of which is less than 50 wt. % of the total support, said catalyst being steamed prior to use at a temperature at least 600.degree. C. In a preferred embodiment, the support will comprise a mixture of silica and the .gamma.-alumina wherein the silica content is less than 25 wt. % thereof. Further, one may employ steam in the cracking zone.

Hydrocarbon conversion processes using improved transition metal oxide

Acidic gases containing carbon dioxide are removed from a normally gaseous mixture by absorbing CO.sub.2 from the gaseous mixture with an aqueous solution comprising a basic alkali metal salt or hydroxide and an activator or promoter system for the salt or hydroxide which contains (i) at least one non-sterically hindered diamine defined as having both a primary and a tertiary amino moiety wherein the primary amino moiety is attached to a primary carbon atom, and (ii) an amino acid, and desorbing at least partially the absorbed CO.sub.2 from the aqueous solution.

Process for removing acid gases using a basic salt activated with a

Acidic gases containing carbon dioxide are removed from a normally gaseous mixture by absorbing CO.sub.2 from the gaseous mixture with an aqueous solution comprising a basic alkali metal salt or hydroxide and an activator or promoter system for the salt or hydroxide which contains (i) at least one diaminoalcohol of the formula:

Acidic gases such as carbon dioxide are removed from a gaseous mixture including the acidic component by contacting the gaseous mixture in a scrubbing system with an acid absorbing solution comprising a basic alkali metal compound and an activator, during which process at least a portion of the activator is converted to cyclic urea. At least a portion of the scrubbing solution is transferred to a thermal conversion zone wherein at least a portion of the cyclic urea is converted back to the activator afterwhich the scrubbing solution is returned to the scrubbing system from the thermal conversion zone.

Process for converting cyclic urea to corresponding diamine in a gas

An acid catalyst comprising a catalytic component selected from the group consisting of oxides of tungsten, niobium and mixtures thereof and tungsten or niobium oxides in combination with one or more additional metal oxides selected from the group consisting of tantalum oxide, hafnium oxide, chromium oxide, titanium oxide and zirconium oxide on an inorganic refractory oxide support is prepared by depositing by means known in the art a metal oxide precursor salt on an inorganic refractory metal oxide which is not itself an acid cracking catalyst or by intimately mixing a metal oxide precursor salt with a refractory metal oxide support precursor salt, converting the salt or salts to the respective metal oxides and subjecting the resultant combination to steaming at elevated temperatures prior to use. Catalysts prepared in this manner exhibit enhanced activity and selectivity as compared to conventional acid catalysts. They also exhibit remarkable resistance to coke make.

Method for preparing a group IVB, VB or VIB metal oxide on inorganic

It has been discovered and forms the basis of the disclosure that various acid catalyzed hydrocarbon conversion processes such as catalytic cracking of gas oil; xylene isomerization; toluene disproportionation; dealkylation of aromatics; ethylene, butylene, isobutylene, propylene polymerization; olefin isomerization; alcohol dehydration; olefin hydration; alkylation; heavy ends cat cracking, etc. are dramatically improved insofar as percent conversion, and selectivity are concerned by the use of a catalyst selected from the group consisting of the oxides of tungsten, niobium and mixtures thereof, and tungsten or niobium oxides in combination with one or more additional metal oxides selected from the group consisting of tantalum oxide, hafnium oxide, chromium oxide, titanium oxide and zirconium oxide, supported on an inorganic refractory oxide support. These catalysts may be prepared by the methods known in the art, i.e., incipient wetness, impregnation, coprecipitation, etc. of the metal oxide precursor onto or with the supports followed by conversion into the oxide form. Before use, the metal oxide/support combination is preferably subjected to steaming at elevated temperatures either before introduction into the reactor or in situ in the process reactor. Conventional catalytic cracking catalysts are unstable at the elevated temperatures where the metal oxide/support combinations of the present invention are uniquely stable.

Acid catalyzed hydrocarbon conversion processes utilizing a catalyst

This invention relates to a method of producing a dibenzocycloheptene compound of the structure ##STR1## in high yields which comprises: (a) hydrogenating an anthracene derivative in the 9,10 position to form a 9,10-dihydroanthracene derivative, (b) selectively mono-carbonylating one of the hydrogens in the 9,10 position to form a monoaldehyde, (c) reducing the aldehyde to form the corresponding alcohol and (d) dehydrating and expanding the center ring to form the dibenzocycloheptene compound.

Method for the preparation of dibenzocycloheptenes from anthracene

Anhydrous TaF.sub.5 can be synthesized from a mixture comprising water and fluorotantalic acids by contacting said mixture with a dehydrating agent. Preferably, said mixture is formed by contacting tantalum oxides, tantalum oxide-halides or mixtures thereof with HF. The dehydrating agent should be a compound that contains carbon-chlorine bonds, carbon-bromine bonds or mixtures thereof.

Preparation of anhydrous TaF.sub.5

A catalyst comprising at least one metal selected from the group consisting of rhodium, palladium, ruthenium, iridium and platinum in combination with a Group VB element supported on a porous carrier is employed in the hydrocracking of heavy aromatic hydrocarbons using steam as the hydrogen source. The product consists mainly of hydrogen, carbon dioxide and lower molecular weight aromatic hydrocarbons. The catalyst is especially useful for the dealkylation of aromatic hydrocarbons.

Growing community of inventors

Somerset, NJ, United States of America

Chang J Kim