Abstract: Aromatic hydrocarbons containing controlled proportions of xylene isomers and benzene may be produced by a process combining dehydrocyclodimerization of C.sub.2 -C.sub.5 aliphatic hydrocarbons, separation of benzene and toluene, and selective methylation.

Abstract: A hydrocarbon conversion process is disclosed which extends the useful life of a regenerable zeolite-containing hydrocarbon conversion catalyst. In one aspect of this process, a hydrocarbon feed containing fluorides is passed through a fluoride removal system which reduces the fluoride concentration of the feed to below 100 ppb. The hydrocarbon feed containing less than 100 ppb fluorine is then converted over a regenerable zeolite-containing hydrocarbon conversion catalyst. The zeolite-containing hydrocarbon conversion catalyst is regenerated with an oxygen-containing gas stream as necessary to burn off carbonaceous deposits on the catalyst so as to return the zeolite catalyst to a high level of activity.

Abstract: Disclosed is a multi-stage catalytic process for the production of aromatics from a feedstock comprising C.sub.2 -C.sub.5 olefins. The process comprises the steps of: (1) passing a hydrocarbon feedstock comprising C.sub.2 -C.sub.5 olefins into a hydrogenation reaction zone in the presence of a hydrogen and a hydrogenation catalyst to produce a hydrogenation reaction zone product essentially free of olefins; and (2) passing the hydrogenation reaction zone product into a dehydrocyclodimerization reaction zone containing a dehydrocyclodimerization catalyst at conditions whereby a dehydrocyclodimerization reaction zone product comprising aromatics is produced.

Abstract: A process is disclosed for the conversion of a light aliphatic hydrocarbon, such as propane, into benzene and optionally also naphthalene. The feed hydrocarbon is converted to aromatic hydrocarbons in a dehydrocyclodimerization zone. The aromatics, and other cyclic hydrocarbons, are passed into a hydrodealkylation zone which is preferably supplied with hydrogen produced in the dehydrocyclodimerization zone. Benzene may be separated from the effluent of the dehydrocyclodimerization zone prior to passage of the aromatics into the hydrodealkylation zone.

Abstract: A process is disclosed for the catalytic conversion of an olefin-containing C.sub.3 and/or C.sub.4 feed (1) into aromatic hydrocarbons (22) and C.sub.3 and/or C.sub.4 paraffins (25,26). The process may result in a net consumption of hydrogen and operates at relatively mild temperature conditions, with preferred temperatures in the reaction zone (4) being less than 425 degrees Celsius. The severity of the operating conditions and the length of time the catalyst is used are controlled to hold down total carbon deposition and to increase aromatics selectivity. A catalyst comprising gallium supported on a zeolite containing base is preferred. The feed stream contains a mixture of paraffins and olefins, with aromatics production being directly related to feed olefin content.

Abstract: A process for catalytic dehydrocyclodimerization and regeneration of the catalyst. C.sub.2 to C.sub.5 aliphatic hydrocarbons are reacted to produce aromatics, using a catalyst of a composition especially adapted to minimize deposition of coke on the catalyst. The catalyst is comprised of alumina which contains phosphorus, gallium, and a crystalline aluminosilicate having a silica to alumina ratio of at least 12. The use of this catalyst has resulted in a five-fold reduction in the rate of coke deposition, compared to a conventional dehydrocyclodimerization catalyst. However, the activity of this catalyst once it becomes deactivated is only recovered by burning the coke accumulated upon the deactivated catalyst at catalyst regeneration conditions in the presence of an oxygen-containing gas.

Abstract: A hydrocarbon conversion process is disclosed which extends the useful life of a regenerable zeolite-containing hydrocarbon conversion catalyst. In one aspect of this process, a hydrocarbon feed containing fluorides is passed through a fluoride removal system which reduces the fluoride concentration of the feed to below 100 ppb. The hydrocarbon feed containing less than 100 ppb fluorine is then converted over a regenerable zeolite-containing hydrocarbon conversion catalyst. The zeolite-containing hydrocarbon conversion catalyst is regenerated with an oxygen-containing gas stream as necessary to burn off carbonaceous deposits on the catalyst so as to return the zeolite catalyst to a high level of activity.

Abstract: A process for catalytic dehydrocyclodimerization and regeneration of the catalyst. C.sub.2 to C.sub.5 aliphatic hydrocarbons are reacted to produce aromatics, using a water-sensitive catalyst of a composition especially adapted to minimize deposition of coke on the catalyst. The catalyst is comprised of alumina which contains phosphorus, gallium, and a crystalline aluminosilicate having a silica to alumina ratio of at least 12. The use of this catalyst has resulted in a five-fold reduction in the rate of coke deposition, compared to a conventional dehydrocyclodimerization catalyst. However, the activity of this catalyst is significantly reduced by exposure to water at the temperatures normally used in removing the coke, which is accomplished by burning the coke in a combustion zone in the presence of oxygen, producing carbon dioxide and water. At least a portion of the gas leaving the combustion zone catalyst bed is combined with air and recycled back to the combustion zone.