Abstract: In the catalytic hydroprocessing of hydrocarbons, a hydrocarbon oil is successively contacted with a first hydroprocessing catalyst in a first reaction zone and a second hydroprocessing catalyst in a second reaction zone. The first catalyst has an average pore diameter at least about 30 angstroms larger than the second catalyst, although both have narrow pore size distributions wherein at least about 90 percent of the total pore volume is in pores of diameter from about 100 angstroms to about 300 angstroms, and with essentially all the pores having diameters greater than 100 angstroms.

Abstract: Reduction of CO and SO.sub.x emissions from regenerators associated with cyclical fluidized catalytic cracking (FCC) units used to convert hydrocarbon feedstocks into more valuable products is achieved by introducing particles of bastnaesite into the FCC unit. The bastnaesite particles recycle with the catalyst particles successively through a catalytic cracking reaction zone, a stripping zone, and a regeneration zone. The bastnaesite particles react with SO.sub.x produced in the regeneration zone of the FCC unit, thereby lowering the SO.sub.x content of the flue gas discharged therefrom. In the catalytic cracking and stripping zones of the FCC unit, the bastnaesite particles are at least partially reactivated so that upon returning to the regeneration zone yet more SO.sub.2 is removed. The bastnaesite particles also aid in lowering CO emissions from the FCC regenerator by catalyzing the reaction between CO and oxygen to yield CO.sub.2.

Abstract: Reduction of CO and SO.sub.x emissions from regenerators associated with cyclical fluidized catalytic cracking (FCC) units used to convert hydrocarbon feedstocks into more valuable products is achieved by introducing particles of bastnaesite into the FCC unit. The bastnaesite particles recycle with the catalyst particles successively through a catalytic cracking reaction zone, a stripping zone, and a regeneration zone. The bastnaesite particles react with SO.sub.x produced in the regeneration zone of the FCC unit, thereby lowering the SO.sub.x content of the flue gas discharged therefrom. In the catalytic cracking and stripping zones of the FCC unit, the bastnaesite particles are at least partially reactivated so that upon returning to the regeneration zone yet more SO.sub.2 is removed. The bastnaesite particles also aid in lowering CO emissions from the FCC regenerator by catalyzing the reaction between CO and oxygen to yield CO.sub.2.

Abstract: Reduction of CO and SO.sub.x emissions from regenerators associated with cyclical fluidized catalytic cracking (FCC) units used to convert hydrocarbon feedstocks into more valuable products is achieved by introducing particles of bastnaesite into the FCC unit. The bastnaesite particles recycle with the catalyst particles successively through a catalytic cracking reaction zone, a stripping zone, and a regeneration zone. The bastnaesite particles react with SO.sub.x produced in the regeneration zone of the FCC unit, thereby lowering the SO.sub.x content of the flue gas discharged therefrom. In the catalytic cracking and stripping zones of the FCC unit, the bastnaesite particles are at least partially reactivated so that upon returning to the regeneration zone yet more SO.sub.2 is removed. The bastnaesite particles also aid in lowering CO emissions from the FCC regenerator by catalyzing the reaction between CO and oxygen to yield CO.sub.2.

Abstract: The life of cracking catalysts treating metals-containing hydrocarbon feedstocks is extended by depositing aluminum components on the surface of the catalyst particles.

Abstract: Reduction of SO.sub.x emissions from the regenerator associated with the fluidized catalytic cracking (FCC) unit for converting hydrocarbon feedstocks into more valuable products is achieved by introducing into the FCC cycle one or more organic, aluminum-containing compounds in dissolved form. In the catalytic cracking zone, the dissolved aluminum-containing compounds are converted to aluminum compounds that deposit relatively uniformly upon the catalyst particles. Also depositing upon the catalyst particles in the catalytic cracking zone are deactivating quantities of sulfur-containing coke. When such catalyst particles are introduced into the regenerator, wherein the sulfur-containing coke present on the catalyst surfaces is removed by combustion, thereby activating the catalyst particles, the SO.sub.x so produced reacts with the deposited aluminum compounds to form one or more stable, sulfur-aluminum oxidic compounds, thus desulfurizing the regenerator flue gas.

Abstract: Nickel-alumina catalysts having a remarkably high degree of thermal stability, and active for the hydrogenation of carbon oxides (methanation), steam reforming, gasification, etc. are prepared by a novel "precipitative-occlusion" method. This method involves digesting a slurry of an alumina hydrate in an aqueous solution of an ammino complex of a nickel salt. The digestion is carried out at a temperature sufficiently high to decompose the ammino complex and "release" the nickel (II) ions. This results in a gradual precipitation of nickel hydroxide in the pores and interstices formed by the agglomerating particles of alumina hydrate. The coflocculated solids are recovered as by filtration, washed, dried and calcined. The resulting compositions are found, in high temperature reactions such as methanation, to retain their activity for much longer periods of time than do conventional nickel-alumina catalysts prepared by the most widely used prior art technique, viz, coprecipitation.

Abstract: A multi-catalyst system is provided which is effective for the conversion of nitrogen oxides, carbon monoxide and hydrocarbons in near stoichiometric engine exhaust gases in a single conversion zone to which no additional air is admitted. The system comprises at least two separate but contiguous components. The first component comprises a porous inert support having dispersed thereon rhodium plus nickel and/or cobalt, and is essentially free of platinum and palladium. The second component comprises a porous inert support having dispersed thereon platinum and/or palladium, with or without nickel and/or cobalt, and is essentially free of rhodium.

Abstract: Nickel-alumina catalysts having a remarkably high degree of thermal stability, and active for the hydrogenation of carbon oxides (methanation), are prepared by a novel "precipitative-occlusion" method. This method involves digesting a slurry of an alumina hydrate in an aqueous solution of an amino complex of a nickel salt. The digestion is carried out at a temperature sufficiently high to decompose the amino complex and "release" the nickel (II) ions. This results in a gradual precipitation of nickel hydroxide in the pores and interstices formed by the agglomerating particles of alumina hydrate. The coflocculated solids are recovered as by filtration, washed, dried and calcined. The resulting compositions are found, in high temperature reactions such as methanation, to retain their activity for much longer periods of time than do conventional nickel-alumina catalysts prepared by the most widely used prior art technique, viz., coprecipitation.

Abstract: A porous catalytic composite is provided which is effective for the simultaneous conversion of nitrogen oxides, carbon monoxide and hydrocarbons in engine exhaust gases. The composite comprises at least two physically separate but contiguous components. The first component comprises a porous inert support having dispersed thereon rhodium plus nickel and/or cobalt, and is essentially free of platinum and palladium. The second component comprises a porous inert support having dispersed thereon platinum and/or palladium, with or without nickel and/or cobalt, and is essentially free of rhodium.

Abstract: Nickel-alumina catalysts having a remarkably high degree of thermal stability, and active for the hydrogenation of carbon oxides (methanation), steam reforming, gasification, etc. are prepared by a novel "precipitative-occlusion" method. This method involves digesting a slurry of an alumina hydrate in an aqueous solution of an ammino complex of a nickel salt. The digestion is carried out at a temperature sufficiently high to decompose the ammino complex and "release" the nickel (II) ions. This results in a gradual precipitation of nickel hydroxide in the pores and interstices formed by the agglomerating particles of alumina hydrate. The coflocculated solids are recovered as by filtration, washed, dried and calcined. The resulting compositions are found, in high temperature reactions such as methanation, to retain their activity for much longer periods of time than do conventional nickel-alumina catalysts prepared by the most widely used prior art technique, viz., coprecipitation.

Abstract: A method for the rejuvenation of an automobile emission control catalyst poisoned with deposited compounds of lead and/or phosphorus is disclosed, said method comprising (a) initially extracting some of the poison compounds from the catalyst with a select aqueous ammonium or acetate salt (preferably ammonium acetate) solution; (b) exposing the catalyst to a reducing atmosphere at 300.degree. to 700.degree. C., and finally (c) removing at least a portion of the poison compounds by a second extraction with a select aqueous ammonium or acetate salt solution. Catalysts contemplated for rejuvenation herein include those comprising nickel, palladium, rhodium, platinum, or combinations thereof as active components on bases of alumina or aluminum borate.

Abstract: Certain crystalline aluminum borate catalyst supports containing about 8-25 weight-percent of B.sub.2 O.sub.3 are found to provide unusually stable and active catalysts for high-temperature chemical conversions, particularly exhaust gas conversion, when prepared by precalcining shaped composites of alumina and boria at temperatures between about 1250.degree. and 2600.degree. F, prior to the addition thereto of active metal or metals. Calcination at below 1250.degree. F is found to yield amorphous catalysts of inferior activity, while at temperatures above 2600.degree. F drastic reductions in surface area may occur.

Abstract: Certain crystalline aluminum borate catalyst supports containing about 8-25 weight-percent of B.sub.2 O.sub.3 are found to provide unusually stable and active catalysts for high-temperature chemical conversions, particularly exhaust gas conversion, when prepared by precalcining shaped composites of alumina and boria at temperatures between about 1250.degree. and 2600.degree.F, prior to the addition thereto of active metal or metals. Calcination at below 1250.degree. F is found to yield amorphous catalysts of inferior activity, while at temperatures above 2600.degree. F drastic reductions in surface area may occur.

Abstract: Process and catalyst for the catalytic conversion of nitrogen oxides (NO.sub.x), unburned hydrocarbons and carbon monoxide in internal combustion engine exhaust gases. The catalyst comprises essentially a composite of nickel and a minor proportion of iridium. This composite catalyst is found to be exceptionally resistant to poisoning by sulfur and lead compounds present in the exhaust gases.

Abstract: Process and catalyst for the catalytic conversion of nitrogen oxides (NO.sub.x), unburned hydrocarbons and carbon monoxide in internal combustion engine exhaust gases. The catalyst comprises rhodium as the essential active component, preferably composited with a nickel component. These catalysts are found to be exceptionally resistant to poisoning by sulfur and lead compounds present in the exhaust gases.

Abstract: A method for the rejuvenation of an automobile emission control catalyst poisoned with compounds of lead and/or phosphorus comprising (a) initially extracting lead sulfate deposits from the catalyst with an aqueous ammonium salt (preferrably ammonium acetate) solution; (b) exposing the catalyst to an atmosphere containing SO.sub.2, or SO.sub.2 and air, at 300.degree. to 700.degree.C. until other lead compounds are substantially converted to lead sulfate, and phosphorus compounds are substantially converted to gaseous P.sub.2 O.sub.5 ; and finally (c) removing at least a portion of the lead sulfate formed in (b) by a second extraction with an aqueous ammonium salt solution.Catalysts contemplated for rejuvenation by the process of the invention include those comprising nickel, palladium, rhodium, platinum, or combinations thereof as active components on bases of alumina or aluminum borate.