Abstract: Carbon monoxide and sulfur oxides are removed from flue gas produced in a catalyst regenerator in an FCC system and sulfur from the flue gas is shifted to form hydrogen sulfide, which is recovered in the gases removed from the cracking reactor in the system by introducing sufficient molecular oxygen into the catalyst regenerator to provide an atmosphere therein having a molecular oxygen concentration of at least 0.1 volume percent, reacting carbon monoxide in the regenerator flue gas with oxygen in contact with a particulate carbon monoxide combustion promoter physically admixed with the cracking catalyst, reacting sulfur oxides in the regenerator flue gas with silica-free alumina included as a discrete phase in the FCC catalyst to form a sulfur-containing solid in the catalyst, and forming hydrogen sulfide in the cracking reactor by contacting the sulfur-containing solid with the hydrocarbon feed.

Abstract: Carbon monoxide and sulfur oxides are removed from flue gas produced in a catalyst regenerator in an FCC system and sulfur from the flue gas is shifted to form hydrogen sulfide, which is recovered in the gases removed from the cracking reactor in the system by reacting carbon monoxide in the regenerator flue gas with oxygen in contact with a particulate carbon monoxide combustion promoter, reacting sulfur oxides in the regenerator flue gas with particulate alumina physically mixed with the FCC catalyst to form a sulfur-containing solid, and forming hydrogen sulfide in the cracking reactor by contacting the sulfur-containing solid with the hydrocarbon feed.

Abstract: Sulfur oxides are removed from flue gas in a catalyst regenerator in a fluid catalyst cracking system while liquid-hydrocarbon product yield from the system is maintained at a high level by heating a particulate silica-containing cracking catalyst to 800-1500.degree. F; impregnating 0.1 to 25 weight percent aluminum onto the catalyst particles; and cycling the resulting particles through the cracking reactor and catalyst regenerator in the cracking system.

Abstract: Sulfur oxides are removed from a gas and the sulfur is converted to hydrogen sulfide by the steps of: (1) reacting sulfur oxides in the gas with alumina to form a solid sulfur-containing compound and remove sulfur oxides from the gas; and (2) contacting the solid compound resulting from step (1) with a hydrocarbon at a temperature of about 800.degree.-1300.degree. F and reacting the solid sulfur-containing compound with components of the hydrocarbon to form hydrogen sulfide.

Abstract: A process is provided for preparing catalytically active emerald green colored alumina by contacting colorless alumina with carbonyl sulfide. This material catalyzes the reduction of sulfur dioxide by carbon monoxide.