Abstract: There is provided a zeolite catalyst, which is first selectivated with a siliceous material and then treated with an aqueous solution comprising alkaline earth metal ions under ion exchange conditions.

Abstract: A process for shape-selective hydrocarbon conversion that involves initially contacting a feed stream which includes an alkylaromatic compound and a co-feed of water, under conversion conditions with a catalytic molecular sieve. Preferably, the catalytic molecular sieve has been modified by being ex situ selectivated with a silicon compound. After an effective amount of time, the water co-feed is omitted from the feed stream and the hydrocarbon conversion process is continued. Optionally, the catalytic molecular sieve can also be in situ trim-selectivated.

Abstract: A dry, regenerable solid oxide process directed to convert SO.sub.x from the flue gas stream from a power plant, a coal or oil-fired plant or process heat furnace, or an FCC regenerator to elemental sulfur without using a Claus unit, a hydrogen plant, a regeneration gas separation system, or a hydrogenation section. This dry, regenerable solid oxide process is also effective on Claus plant tail-gas. This process uses solid oxides, such as, for example, magnesium aluminates or spinels to remove sulfur oxides from flue gas streams. The solid oxide is then regenerated by a reducing gas to release the sulfur compounds contained on the solid oxide to produce a gas stream comprising hydrogen sulfide, sulfur oxides and elemental sulfur. The elemental sulfur is then condensed and recovered as a product and the resulting gas stream may be recycled to be reprocessed over the solid oxide.

Abstract: There is provided a process directed to the use of gases containing or mixed with carbon monoxide, such as synthesis gas, to aid in the regeneration of sulfur oxide-sorbed solid oxides, such as magnesium aluminates or spinels. This process is especially useful in applications where the solid oxide is used to purify the flue gas stream from an FCC regenerator, coal or oil-fired plant, power plant or process heat furnace, or the tail gas from a Claus plant. The process is also useful to remove sulfur oxides from flue gases produced in solid fuel combusters. According to this invention, carbon monoxide may be used alone or in combination with other gases to make the regeneration of the solid oxide exothermic or less endothermic, thereby improving the effectiveness of the regeneration.

Abstract: There is provided a catalyst comprising a hydrogenation/dehydrogenation component, such as a noble metal, and an acidic solid component comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal. An example of this catalyst is zirconia, modified with tungstate and platinum. There is also provided a method for preparing this catalyst. This catalyst may be used, for example, to isomerize C.sub.4 to C.sub.8 paraffins. The feed to this paraffin isomerization reaction may, optionally, include cyclic hydrocarbons, such as benzene or cyclohexane, which may undergo ring opening reactions during the course of the isomerization reaction.

Abstract: A mixture of aromatic hydrocarbons, comprising ethylbenzene and at least one xylene, is isomerized using a two reactor system to convert the ethylbenzene to compounds that may be removed from the aromatic hydrocarbon stream and to produce a product stream wherein the para-xylene concentration is approximately equal to the equilibrium ratio of the para-isomer. The catalyst present in the first reactor is one that is effective for ethylbenzene conversion with minimal xylene loss when operated under suitable conversion conditions, e.g., a catalyst comprising silica bound ZSM-5 that has been selectivated by one or more silicon impregnations or that has been coke selectivated. The catalyst present in the second reactor is one which is effective to catalyze xylene isomerization when operated under suitable conditions. Each of the catalysts of this invention may contain one or more hydrogenation or dehydrogenation components.

Abstract: There is provided a process for the alkylation of toluene with ethylene to selectively produce para-ethyltoluene over a catalyst which has been selectivated by multiple treatments with a siliceous material.

Abstract: A mixture of aromatic hydrocarbons, comprising ethylbenzene and at least one xylene, is treated to convert the ethylbenzene to compounds that may be removed from the aromatic hydrocarbon stream and to isomerize any xylenes present. The ethylbenzene conversion catalyst is one that is effective for ethylbenzene conversion with minimal xylene loss, e.g., a silica bound intermediate pore size zeolite that has been selectivated. The xylene isomerization catalyst is one which is effective to catalyze xylene isomerization. Each of the catalysts of this invention may contain one or more hydrogenation or dehydrogenation components.

Abstract: There is provided a process for shape selective toluene disproportionation that involves contacting a feedstream which includes toluene under conversion conditions, with ZSM-5 that has been selectivated at least once with an organosilicon selectivating agent. The conversion conditions of the hydrocarbon conversion process provide a toluene conversion of at least 40 wt. %.

Abstract: There is provided a continuous toluene disproportionation process to selectively produce para-xylene. The process includes a steady-state of operation, wherein the conversion of toluene and selectivity to para-xylene is maintained at essentially constant target levels. Prior to such a steady-state of operation, the reaction is conducted under a relatively high temperature.

Abstract: There is provided a zeolite catalyst, which is first selectivated with a siliceous material and then treated with an aqueous solution comprising alkali metal ions under ion exchange conditions.

Abstract: There is provided zeolite catalyst, which is first selectivated with a siliceous material and then treated with an aqueous solution comprising ammonium or organoammonium ions under ion exchange conditions.

Abstract: There is provided a zeolite catalyst, which is first selectivated with a siliceous material and then washed with a liquid. The washing step may comprise slurrying the catalyst in water and recovering the washed catalyst by filtration.

Abstract: There is provided a zeolite catalyst, which is first selectivated with a siliceous material and then treated with an aqueous solution comprising a dealuminizing agent such as an acid or a chelating agent.

Abstract: There is provided a process for the net catalytic oxidative dehydrogenation of alkanes to produce alkenes. The process involves simultaneous equilibrium dehydrogenation of alkanes to alkenes and combustion of the hydrogen formed to drive the equilibrium dehydrogenation reaction further to the product alkenes. In the present reaction, the alkane feed is dehydrogenated over an equilbrium dehydrogenation catalyst in a first reactor, and the effluent from the first reactor is then passed into a second reactor containing a reducible metal oxide which serves to selectively combust hydrogen in an oxidation/reduction (REDOX) reaction. This particular mode of operation is termed a separate reactor, REDOX mode.

Abstract: There is provided a process for the alkylation of ethylbenzene with ethylene to selectively produce para-diethylbenzene over a catalyst which has been selectivated by multiple treatments with a siliceous material.

Abstract: There is provided a process for the net catalytic oxidative dehydrogenation of alkanes to produce alkenes. The process involves simultaneous equilibrium dehydrogenation of alkanes to alkenes and combustion of the hydrogen formed to drive the equilibrium dehydrogenation reaction further to the product alkenes. In the present reaction, the alkane feed is passed into a reactor containing both an equilibrium dehydrogenation catalyst and a reducible metal oxide, whereby the alkane is dehydrogenated and the hydrogen produced is simultaneously and selectively combusted in oxidation/ reduction (REDOX) reaction with the reducible metal oxide. This particular mode of operation is termed a same reactor, REDOX mode. The equilibrium dehydrogenation catalyst may comprise platinum and the reducible metal oxide may contain bismuth, antimony, indium, or molybdenum, or a mixture thereof.

Abstract: There is provided a process for the net catalytic oxidative dehydrogenation of alkanes to produce alkenes. The process involves simultaneous equilibrium dehydrogenation of alkanes to alkenes and combustion of the hydrogen formed to drive the equilibrium dehydrogenation reaction further to the product alkenes. In the present reaction, the alkane feed is dehydrogenated over an equilbrium dehydrogenation catalyst in a first reactor, and the effluent from the first reactor, along with oxygen, is then passed into a second reactor containing a metal oxide catalyst which serves to selectively catalyze the combustion of hydrogen. This particular mode of operation is termed a separate reactor, cofed oxygen mode. The equilibrium dehydrogenation catalyst may comprise platinum and the selective metal oxide combustion catalyst may contain bismuth, antimony, indium, molybdenum, or a mixture thereof.

Abstract: With sufficient oxygen but with no added fuel gas, recovering sulfur from a gas stream containing hydrogen sulfide by oxidizing the gas stream with heat exchange from heat generated in a thermal converter section of a sulfur recovery unit to convert the hydrogen sulfide in the gas stream to sulfur oxide, and thus form a sulfur oxide enriched gas stream. The sulfur oxide enriched gas stream is contacted with a solid adsorbent bed to extract the sulfur oxides and retain them as sulfur compounds, thus forming a sulfur oxide depleted gas stream. The adsorbent bed is then contacted with a reducing gas stream to reduce the retained sulfur compounds to hydrogen sulfide and/or sulfur dioxide and thereby form a hydrogen sulfide and/or sulfur dioxide bearing stream. Sulfur is recovered from the hydrogen sulfide and/or sulfur dioxide bearing stream, and the sulfur oxide depleted gas stream maybe sent to an incinerator or vented through a stack.

Abstract: There is provided a process for the net catalytic oxidative dehydrogenation of alkanes to produce alkenes. The process involves simultaneous equilibrium dehydrogenation of alkanes to alkenes and combustion of the hydrogen formed to drive the equilibrium dehydrogenation reaction further to the product alkenes. In the present reaction, the alkane feed is dehydrogenated over an equilbrium dehydrogenation catalyst in a first reactor, and the effluent from the first reactor is then passed into a second reactor containing a reducible metal oxide which serves to selectively combust hydrogen in an oxidation/reduction (REDOX) reaction. This particular mode of operation is termed a separate reactor, REDOX mode.