Abstract: A solid solution for the desulfurization of sulfur containing gases is provided in which the solution contains oxides having oxygen ion vacancies provided therein. The solid solution has a solvent which has at least one lanthanide oxide which crystallizes in the fluorite habit. The solid solution has a solute which contains a second oxide having a valence which differs from the valence of the lanthanide oxide present in the solvent.

Abstract: A process for optimizing the removal of nitrogen oxide (NO.sub.x) and sulfur oxide (SO.sub.X) from flue gases is provided in which the flue gases pass over a lanthanide-oxygen-sulfur catalyst. The catalyst has active sites provided on its surface which promote the dissociation of NO.sub.X and receive and entrap oxygen released during the dissociation of the NO.sub.X. While the flue gases pass over the catalyst, a reducing gas contacts the catalyst to reduce the oxygen on the active sites of the catalyst and permit the catalyst to continue to promote the dissociation of the NO.sub.x in the flue gas. If the flue gases contain SO.sub.X, they are then passed over a solid solution having a solvent of a first lanthanide oxide compound which crystallizes in the fluorite habit and a solute of at least one altervalent oxide of a second lanthanide. The SO.sub.X in the flue gases reacts with the solid solution to form a sulfated lanthanide oxide which is removed from the flue gases.

Abstract: A process for the reduction of sulfur oxides from flue gases is provided in which ammonia is added to the flue gas to precipitate out (NH.sub.4).sub.2 SO.sub.4. The (NH.sub.4).sub.2 SO.sub.4 is collected and can be sold as a commercial product.

Abstract: A process for the removal of chlorine from reducing gases is provided wherein the reducing gases are contacted with cerium oxide. The chlorided cerium oxide is regenerated in an oxidizing atmosphere to provide cerium oxide. This cerium oxide regenerated is again capable of reacting with chlorine in reducing gases.

Abstract: A method for desulfurization of fuel gases resulting from the incomplete combustion of sulfur containing hydrocarbons whereby the gases are treated with lanthanide oxides containing large numbers of oxygen-ion vacancies providing ionic porosity which enhances the ability of the lanthanide oxides to react more rapidly and completely with the sulfur in the fuel gases whereby the sulfur in such gases is reduced to low levels suitable for fuels for firing into boilers of power plants generating electricity with steam turbine driven generators, gas turbines, fuel cells and precursors for liquid fuels such as methanol and the like.

Abstract: A method for the regeneration of sulfur containing cerium compounds formed by the desulfurization of fluid materials containing sulfur with cerium oxide back to its original form, CeO.sub.2, wherein the sulfur containing cerium compounds are removed from contact with the fluid material containing sulfur; the temperature of the sulfur containing cerium compounds is raised above the temperature at which cerium sulfate dissociates; and the sulfur containing cerium compounds whose temperature is above the temperature at which cerium sulfate dissociates is exposed to an oxidizing atmosphere.

Abstract: A method for desulfurizing gases in which the sulfur is mainly in the form of hydrogen sulfide by reacting with one of the forms of cerium oxide with the formation of a cerium-oxygen-sulfur compound, which method can be conducted at temperatures as high as the lowest melting point of either the cerium oxides or cerium-oxygen-sulfur compounds formed by the reactions. The method also includes a definition of the temperature necessary for the regeneration of the cerium-oxygen-sulfur compounds back to cerium oxide which is capable of again reacting with the hydrogen sulfide of the gases being desulfurized whereby the emission of sulfur from the combustion of sulfur containing hydrocarbons is reduced to a level below that attainable with any other method when operated at the same high temperatures.

Abstract: A method for desulfurizing gases in which the sulfur is mainly in the form of hydrogen sulfide by reacting with one of the forms of cerium oxide with the formation of a cerium-oxygen-sulfur compound, which method can be conducted at temperatures as high as the lowest melting point of either the cerium oxides or cerium-oxygen-sulfur compounds formed by the reactions. The method also includes a definition of the temperature necessary for the regeneration of the cerium-oxygen-sulfur compounds back to cerium oxide which is capable of again reacting with the hydrogen sulfide of the gases being desulfurized whereby the emission of sulfur from the combustion of sulfur containing hydrocarbons is reduced to a level below that attainable with any other method when operated at the same high temperatures.

Abstract: A method for desulfurizing fluid materials, comprising reacting sulfur to be removed with a rare earth compound, thereby forming rare earth sulfides, oxysulfides or mixtures thereof. The reaction is conducted under conditions of low oxygen potential. Rare earth sulfides and oxysulfides can be reacted with oxygen to restore a capacity for desulfurization.

Abstract: A method for desulfurizing fluid materials, comprising reacting sulfur to be removed with a rare earth compound, thereby forming rare earth sulfides, oxysulfides or mixtures thereof. The reaction is conducted under conditions of low oxygen potential. Rare earth sulfides and oxysulfides can be reacted with oxygen to restore a capacity for desulfurization.

Abstract: A method for desulphurizing fluid materials such as molten iron, steel, stack gases, synthetic natural gases, boiler gases, coal gasification and liquification products and the like is provided in which one of the group rare earth oxides, rare earth fluocarbonates, rare earth oxyfluorides and mixtures thereof, including bastnasite concentrates are reacted at low oxygen potential, with the sulphur to be removed to form one of the group consisting of rare earth sulphides, rare earth oxysulphides and mixtures thereof. The low oxygen potential can be achieved by carrying out the reaction in the presence of vacuum, reducing gases, carbon, etc.

Abstract: A method for desulphurizing fluid materials such as molten iron, steel, stack gases, synthetic natural gases, boiler gases, coal gasification and liquification products and the like is provided in which one of the group rare earth oxides, rare earth fluocarbonates, rare earth oxyfluorides and mixtures thereof, including bastnasite concentrates are reacted at low oxygen potential, with the sulphur to be removed to form one of the group consisting of rare earth sulphides, rare earth oxysulphides and mixtures thereof. The low oxygen potential can be achieved by carrying out the reaction in the presence of vacuum, reducing gases, carbon, etc.

Abstract: A method for desulphurizing iron, steel, stack gases and the like is provided in which rare earth oxides are reacted, in the presence of an agent, such as carbon, vacuum, reducing gases, etc. for reducing the oxygen level, with the sulphur to be removed to form one of the group consisting of rare earth sulphides, rare earth oxysulphides and mixtures thereof.