Abstract: Hydrolysis of COS in gas streams to H.sub.2 S and CO.sub.2 can be improved by using certain bicyclo tertiary amine catalysts. Bicyclo tertiary amine catalysts can enhance COS hydrolysis in an acid gas removal solvent in the liquid phase or on a solid support system in the gas phase.

Abstract: A process for the removal of HCN from gaseous streams is described, the process being characterized by reaction of the HCN in the gaseous stream with an ammonium polysulfide solution and formation of ammonium thiocyanate in solution, precipitation and removal of sulfur from the ammonium thiocyanate-containing solution, and hydrolysis of the ammonium thiocyanate. Provision is made for recycle of hydrolysis products.

Abstract: A process for the removal of HCN from gaseous streams is described, the process being characterized by reaction of the HCN in the gaseous stream with an ammonium polysulfide solution, formation of ammonium thiocyanate in solution, decomposition of ammonium polysulfide and precipitation of sulfur from the ammonium thiocyanate solution in a stripping zone, and hydrolysis of the ammonium thiocyanate. Recycle or recovery of sulfur and hydrolysis products are contemplated.

Abstract: Process for hydrodesulfurizing and deoxygenating a gas (A) comprising methane, oxygen and at least one organic sulfur compound, said process comprising contacting a mixture of said gas (A) with a hydrogen-containing gas (B) first with a palladium-containing catalyst, at a temperature of 300.degree.-450.degree. C., and then with a second catalyst comprising molybdenum and at least one of nickel and cobalt, at a temperature of 300.degree.-450.degree. C.

Abstract: There are employed water soluble low molecular weight polycondensation products produced by the condensation of acrolein and formaldehyde in a molar ratio between 1:1 and 1:10 in aqueous or aqueous-organic medium in the presence of a basic catalyst for the elimination of hydrogen sulfide and iron sulfide present in aqueous systems. The condensation reaction can also be carried out in the additional presence of water soluble monohydric or polyhydric alcohols and/or acid amides.

Abstract: A process for the removal of HCN from gaseous streams is described, the process being characterized by reaction of the HCN in the gaseous stream with an ammonium polysulfide solution, formation of ammonium thiocyanate, and hydrolysis of the ammonium thiocyanate. Recycle of hydrolysis products is contemplated.

Abstract: An acceptor of MnO.sub.x or iron oxide, wherein x has a value of from 1 to 1.5, supported on a (.gamma.)-alumina carrier which may contain silica, is used to remove hydrogen sulfide from process gases. The acceptor is regenerated with steam in a reducing atmosphere at a temperature of from 300.degree. C. to 700.degree. C.

Abstract: Hydrolysis of COS in gas streams to H.sub.2 S and CO.sub.2 can be improved by the addition of certain bicyclo amine catalysts to acid gas removal solvents.

Abstract: Sulfur oxides are removed from a gas by an absorbent which comprises a physical mixture of (1) a particulate cracking catalyst comprising from about 0.5 to about 50 weight percent of a crystalline aluminosilicate zeolite which is distributed throughout a porous matrix wherein said matrix comprises from about 70 to about 100 weight percent of alumina and (2) a particulate solid other than cracking catalyst which comprises at least one inorganic oxide selected from the group consisting of the oxides of aluminum and magnesium in association with at least one free or combined rare earth metal selected from the group consisting of lanthanum, cerium, praseodymium, samarium and dysprosium, wherein the ratio by weight of inorganic oxide or oxides to rare earth metal or metals is from about 1.0 to about 1,000. Absorbed sulfur oxides are recovered as a sulfur-containing gas comprising hydrogen sulfide by contacting the spent absorbent with a hydrocarbon at a temperature from about 375.degree. to about 900.degree. C.

Abstract: Methods and apparatus adaptable to continuous production of hydrogen sulfide by chemical reaction of sulfur with a gaseous sulfur-reducing reactant selected from methane or other hydrocarbons, hydrogen, carbon-containing compounds such as carbon disulfide, gases with high CO contents, e.g. from gasification of coal, or mixtures of such gases are provided utilizing a separately-fired sulfur heater to vaporize liquid sulfur feedstock. Adding steam with the sulfur reduces the temperature level requirements of the sulfur vapors and provides H.sub.2 and O.sub.2 for the hydrolysis reactions. Control of the temperature of the sulfur vapors and steam delivered into the system through the sulfur vaporizer is used to modulate sulfiding reaction temperatures. A major portion of the steam is introduced with the sulfur vapors; a minor portion of the steam can be added with the feedstock reductant gas to assist in heat recovery from the reaction product gases and to facilitate standby conditions.

Abstract: Petroleum coke is processed to reduce the sulfur content. Ground coke is contacted with hot hydrogen, under pressurized conditions, for a residence time of about 2 to 60 seconds. The desulfurized coke is suitable for metallurgical or electrode uses.

Abstract: Flue gas having a content of sulfur dioxide is passed upwardly through a scrubbing tower against a descending flow of recycled aqueous sodium aluminate-sodium hydroxide liquor. The sulfur dioxide in the gas is converted to sodium and aluminum sulfates and sulfites and the liquor removes any fly ash present in the gas. Underflow is continuously discharged from the tower and is sent to an evaporator for removal of excess water. Make-up solutions of sodium sulfate and aluminum sulfate are added, as necessary. Carbonaceous reducing agent is added to the discharge from the evaporator. The mixture is continuously fed into a reducing furnace where the sulfates and sulfites are reduced to sulfides. The product of the furnace (molten sodium and aluminum sulfides) is charged into a continuous hydrolyzer. Hydrogen sulfide is evolved and collected, and, if desired, its sulfur content is converted to elementary sulfur. The underflow from the hydrolyzer is filtered.

Abstract: The invention is a method of treating the distillation residue from the production of phosphorochloridothionates which comprises draining the residue into agitated cold water to form a slurry and contacting the slurry with chlorine gas in a hydrolyzing zone to decompose the residue and produce decomposition gases in controllable amounts having a decreased sulfur content.The novel method would reduce the amount of sulfur in the decomposition gas and make possible the use of less costly abatement facilities.

Abstract: A process for removing sulfur from sulfide-bearing ores by reacting water vapor with the sulfide-bearing ore forming hydrogen sulfide while simultaneously regenerating water vapor by reacting the hydrogen sulfide with lime. Advantageously, the process occurs in the absence of a net consumption or production of gaseous species so that the process can be carried out in a closed system with respect to the gaseous species. Sulfide-bearing ores which can be treated using the process of this invention include sulfide-bearing ores of molybdenum, zinc, iron, mercury, and copper. Advantageously, the molybdenum oxide so produced from the sulfide-bearing ore of molybdenum can be reacted further with lime and water producing calcium molybdate and hydrogen. The chalcopyrite form of the sulfide-bearing ore of copper produces bornite and magnetite.

Abstract: Sulfur oxides are removed from a gas with absorbents and then are removed from the absorbents by contact with a hydrocarbon in the presence of a cracking catalyst. The absorbents comprise an exhaustively-exchanged rare-earth-form zeolite and a free form of an inorganic oxide selected from the group consisting of the oxides of aluminum, magnesium, zinc, titanium, and calcium. The sulfur oxides are removed from the absorbents as a sulfur-containing gas which comprises hydrogen sulfide.

Abstract: A process for removing SO.sub.x pollutants from a stack gas by (1) absorbing the SO.sub.x pollutants into an aqueous absorbent containing a formate compound and (2) regenerating the spent absorbent containing dissolved SO.sub.x compounds by contact, in the presence of added formate anion, with a water-insoluble, solid substance containing one or more tertiary amine functional groups. Nitrogen monoxide is removed by providing in the aqueous absorbent an iron(II) chelate, such as a chelate of ferrous ion with ethylenediaminetetraacetic acid. Regeneration of the spent absorbent containing absorbed NO is accomplished under the same conditions as for spent absorbents containing absorbed SO.sub.x compounds. SO.sub.x and NO pollutants dissolved in the absorbent are, during regeneration, converted to hydrogen sulfide and nitrogen, respectively.

Abstract: A process and apparatus for producing a low sulfur content hot reducing gas by desulfurizing hot reducing gas by contacting the sulfur-bearing hot reducing gas or carbonaceous material with a particulate calcium oxide desulfurizing agent to thereby produce a product gas stream and a byproduct calcium sulfide composition, and then recovering sulfur from the calcium sulfide composition by contacting the calcium sulfide composition with hot liquid water at a temperature and corresponding pressure sufficient to maintain steam in the system and wherein a major portion of the calcium sulfide composition has a particle size of less than about 6 mesh to thereby convert the sulfide to calcium hydroxide and hydrogen sulfide. A preferred process uses this low sulfur content gas to reduce iron ore, and especially wherein ore, calcium oxide and carbonaceous material are reacted in a shaft furnace.

Abstract: Solid carbonaceous material, especially coal or coal char, is desulfurized by treatment with a limited amount of hydrogen to convert the organic sulfur to sulfide sulfur at an elevated temperature. The thusly formed sulfide sulfur is then removed from the solid carbonaceous material by steam treatment or other means.

Abstract: A fuel gas is desulfurized while hot by contact with a molten alkali salt. The salt is regenerated for further use by contact with a recirculating gas stream. The H.sub.2 S and COS picked up by the recirculating gas stream is scrubbed at low temperature in an aqueous alkaline salt scrub system such as hot potash. H.sub.2 S regenerated from the low temperature alkaline scrub system is subsequently converted to sulfur. By combining both high temperature and low temperature alkali scrubbing in a single dual temperature dual alkali (DTDA) process, the best advantages of both scrub techniques are retained whereas the serious disadvantages of molten salt scrubbing are eliminated.

Abstract: The hydrolysis of carbon oxysulfide in a gas or liquid stream is catalyzed by morpholines and piperazines at a temperature in the range from about 50.degree. about 90.degree. C. The process can be used in the treatment of refinery gases, coal gasification streams, and other such gases as well as liquid hydrocarbons which contain COS and other acidic contaminants.

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 nonzeolitic, silica-containing catalyst to 800.degree.-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, the impregnated catalyst being particularly adaptable for cracking heavy, metals-containing feeds such as residua.

Abstract: A process for the control of sulfur oxide emissions from the regenerator of a fluid catalytic cracking unit which involves circulating solid particles through the process cycle which comprise cracking catalyst and a regenerable sulfur oxide absorbent, absorbing sulfur oxides with the particles in the regeneration zone, withdrawing a stream of particles from the regeneration zone and passing the stream to a reducing zone, contacting the particles in the reducing zone with a reducing gas to release absorbed sulfur oxides as a sulfur-containing gas, and returning the stream to the inventory of solid particles which is circulated between the reaction and regeneration zones. The reducing gas comprises at least one component selected from the group consisting of hydrogen and hydrocarbons, and the process conditions in the reducing zone can be adjusted to optimize the release of absorbed sulfur oxides.

Abstract: Dielectric heating with microwaves of saturated solid noncarbon adsorbents to remove the adsorbed materials results in more rapid, efficient and safe regeneration than conventional heating. The microwaves heat the adsorbents internally and in the absence of spark discharges without thermal and mechanical degradation of the adsorbent, and also in the absence of activating gas bring the adsorbents to a temperature sufficient to desorb the adsorbate. Separation of a gas mixture into two concentrated streams of its components is enabled by adsorption of one fraction by a selective adsorbent followed by removal of that fraction with dielectric heating and little or no purge gas. Useful by-products of the separation process are thereby economically recovered.

Abstract: A process and apparatus for producing a low sulfur content, hot reducing gas by desulfurizing hot reducing gas by contacting the sulfur-bearing hot reducing gas with a bed of a particulate calcium oxide desulfurizing agent to thereby produce a product gas stream and a byproduct calcium sulfide composition, and then recovering sulfur from the calcium sulfide composition by contacting the calcium sulfide composition with hot liquid water at a temperature and corresponding pressure sufficient to maintain steam in the system and to thereby convert the sulfide to calcium hydroxide and hydrogen sulfide and to produce a liquid water stream containing sulfur, and then combining the sulfur-containing water stream with a fresh water stream and recycling this water stream for contacting the calcium sulfide composition. Preferably water vapor produced in the contacting step is condensed and returned to the system in the final stage of contacting the calcium sulfide composition with hot liquid water.

Abstract: A process for converting potassium sulfate to potassium carbonate in which a mixture of potassium sulfate and calcium oxide are reacted at a temperature in the range of between about 700.degree. C. and about 800.degree. C. with a gaseous mixture having a minor amount of hydrogen and/or carbon monoxide in a diluent with the calcium oxide being present in an amount not greater than about 20 percent by weight of the potassium sulfate to produce an aqueous mixture of potassium sulfide, potassium bisulfide, potassium hydroxide and calcium sulfide and a gaseous mixture of steam and hydrogen sulfide. The potassium and calcium salts are quenched to produce an aqueous slurry of soluble potassium salts and insoluble calcium salts and a gaseous mixture of steam and hydrogen sulfide. The insoluble calcium salts are then separated from the aqueous solution of soluble potassium salts.

Abstract: Flue gas containing sulfur dioxide is purified (and the sulfur content thereof is recovered in elemental form) by scrubbing the gas with aqueous sodium aluminate-sodium hydroxide solution thereby forming an underflow suspension consisting essentially of sodium and aluminum sulfites and sulfates and fly ash; oxidizing the sulfites to sulfates; evaporating the free water present; reducing the resulting apparently dry mixture of sodium and aluminum sulfates by the action of reactive hydrogen and a carbonaceous reducing agent thereby forming a solid mixture of a sodium oxide and sodium aluminate and a gaseous mixture comprising sulfur dioxide, sulfur, and hydrogen sulfide; condensing said sulfur; and inter-reacting said sulfur dioxide and hydrogen sulfide to provide elemental sulfur. The solid mixture is dissolved in water to regenerate the scrubbing solution, which is then recycled. The solution is filtered at any convenient point to remove fly ash and any other solids present.

Abstract: There is disclosed a multi-stage process for reducing sulfur dioxide to sulfur or to hydrogen sulfide whereby a hydrogen-containing gas from a high temperature gasifier is used. In the first stage of the process, the gasifier exit gas is contacted at a minimum temperature of about 1800.degree. F. with recycle gas containing SO.sub.2, H.sub.2 S, COS, mercaptans, and CS.sub.2 in order primarily to reduce the organic sulfur compounds, i.e., COS, mercaptans, and CS.sub.2, which heretofore would tend to accumulate in prior known methods employing a carbonaceous fuel for the reduction of SO.sub.2. Gas leaving the first stage is then sent to a second stage wherein SO.sub.2 from an external source is added. Reduction of sulfur dioxide occurs in the second stage at a temperature of about 2000.degree. F. minimum, with the surplus heat of reaction removed by the generation of steam. Gas leaves the second stage and is thereafter cooled with simultaneous generation of steam and selective condensation of sulfur vapor.

Abstract: In the Stretford process wherein hydrogen sulfide, obtained for example, in the catalytic conversion of sulfur compounds, is absorbed into an alkaline solution of the sodium salt of anthraquinone disulfonic acid (ADA) and sodium vanadate and eventually converted to elemental sulfur by a reaction of the sodium vanadate with the hydrogen sulfide, some of the hydrogen sulfide undergoes side reactions and is converted to undesirable by-products, e.g., sodium sulfate and sodium thiosulfate. These by-products were removed in the prior art by burning; however, the expensive salts of ADA were also burned in the process of the prior art. In the present improvement, the sodium salts of ADA are preferentially removed in an adsorption column filled with a macroporous adsorption resin, prior to the combustion stage. The adsorption column can be regenerated either with water or with an aqueous solution of sodium carbonate formed in the combustion stage.

Abstract: A process for treating sulfide ores to reduce the sulfur content or recover the metal content therefrom comprises the use of enzymatic action to solubilize the sulfur and metal content.A nutrient, such as a saccharide, is used along with yeast spores which feed on the sugar and produce enzymes which act on sulfur in the sulfide ore to cause the sulfur to go into solution and to dissolve those metals which are soluble in strongly acidic solution. Sulfuric acid can be formed from the sulfide ores or from free sulfur by reaction with water, with evolution of hydrogen sulfide gas. Oxidation of at least a portion of the hydrogen sulfide can be achieved to regenerate sulfuric acid.

Abstract: Sulfur-containing fuels are converted to substantially sulfur-free combustible gas in an integrated process involving part combustion in a dense phase fluidized conversion bed of particles comprising alkaline earth metal oxides. An oxygen-containing gas is passed into the base of the bed to maintain a relatively high fuel/air ratio. Sulfur is chemically fixed in the particles by reaction to form alkaline earth metal sulfide. Particles containing alkaline earth metal sulfide are circulated from one region of the conversion bed to one region of a dense phase fluidized regeneration bed operated at a higher temperature and fluidized by passing into the base thereof an oxygen-containing gas which exothermically regenerates chemically active alkaline earth metal oxide from the sulfide liberating gases which have a low oxygen content and a relatively high content of sulfur moieties (e.g. SO.sub.2).

Abstract: This invention is an apparatus and a process for producing gaseous hydrogen sulfide in concentrated form from sulfur dioxide obtained from a dilute gas source by (1) reacting the SO.sub.2 with Na.sub.2 CO.sub.3 to form Na.sub.2 SO.sub.3, (2) reducing the Na.sub.2 SO.sub.3 to Na.sub.2 S, (3) reacting the Na.sub.2 S with NaHCO.sub.3 to form H.sub.2 S and Na.sub.2 Co.sub.3, (4) recycling part of the Na.sub.2 CO.sub.3 to the SO.sub.2 reaction step, (5) reacting the remainder of the Na.sub.2 CO.sub.3 with CO.sub.2 and H.sub.2 O to form NaHCO.sub.3 and (6) recycling the NaHCO.sub.3 to the H.sub.2 S formation reaction.

Abstract: An improved process for converting hydrocarbons using a catalyst which is periodically regenerated to remove carbonaceous deposits, the catalyst being comprised of a mixture containing, as a major component, solid particles capable of promoting hydrocarbon conversion at hydrocarbon conversion conditions, and, as a minor component, discrete entities comprising a major amount of alumina and, preferably, a minor, catalytically effective amount of at least one platinum group metal component disposed on the alumina, the platinum group metal component being capable of promoting the oxidation of carbon monoxide to carbon dioxide at carbon monoxide oxidizing conditions and/or promoting the oxidation of sulfur dioxide to sulfur trioxide at sulfur dioxide oxidizing conditions.Improved hydrocarbon conversion-carbon monoxide oxidation catalyst and hydrocarbon conversion-sulfur dioxide oxidation catalyst are also disclosed.

Abstract: In a magnetohydrodynamic power plant where calcium carbonate seed is used to increase conductivity and scavenge sulfur, forming potassium sulfate, an improved process is disclosed for converting the potassium sulfate back into potassium carbonate for reuse in the power plant. The potassium sulfate is first reacted with a reducing agent in the presence of up to about 40% boric oxide at about 800.degree. to about 1300.degree. C. for at least about one hour to produce potassium sulfide. The potassium sulfide is then reacted with carbon dioxide and steam at about 450.degree. to about 750.degree. C. for at least about an hour to produce hydrogen sulfide and potassium carbonate. Finally, the potassium carbonate and the hydrogen sulfide are separated and the potassium carbonate is recycled.

Abstract: An improved method for recovering sulfur from flue gas which contains sulfur dioxide formed from burning sulfur containing fuels. The method first involves the reduction burning of auxilary fuel in the presence of sodium sulfite to convert it to smelt containing sodium sulfide and sodium carbonate. The smelt is dissolved, and the solution reacted with carbon dioxide, hydrogen sulfide and water vapor forming sodium hydrosulfide. The sodium hydrosulfide is reacted with a high concentration of recycled sodium bicarbonate and stripped with carbon dioxide to form sodium carbonate and release the sulfides as hydrogen sulfide from the stripper. The hydrogen sulfide released is then converted to sulfur dioxide, sulfuric acid or elemental sulfur. Pressurized carbon dioxide is used for pressure carbonation of recycled solution from the stripper to convert the sodium carbonate to the high concentration of recycled sodium bicarbonate used for stripping.

Abstract: A process for reacting potassium carbonate with the sulfur in an MHD gas to form potassium sulfate and for recovering the potassium carbonate for recycle as a seeding material for the MHD gas.

Abstract: A process is provided for adsorbing sulfur dioxide impurity from an impure gas and producing a hydrogen sulfide-rich gas. In the process, a first adsorbate containing oxidized sulfur is produced by contacting the impure gas with an adsorbent comprising a composite of an alumina support and sodium and vanadium oxides. A second adsorbate containing reduced sulfur is produced by contacting said first adsorbate with carbon monoxide. A gas rich in hydrogen sulfide is then produced by contacting said second adsorbate with water vapor at a temperature in the range 120.degree. C. to 815.degree. C.

Abstract: Gasification by reaction of carbon (e.g., in coal) with sulfur in the presence of steam, at 500.degree.-1500.degree. K., and controlled to favor production of carbon monoxide/-dioxide and hydrogen sulfide (further reactable to hydrogen and sulfur, which can be recycled). Heat generated by combustion of reaction products and/or through possible exothermic portions of the process can be utilized in the process for preheating reagents or reducing energy requirements of the main reaction.

Abstract: A process for the removal of oxidizable sulfur compounds from a waste gas which comprises:(a) mixing a waste gas containing compounds oxidizable to sulfur oxides with molecular oxygen and oxidizing said compounds to sulfur oxides;(b) contacting the oxidized gas with a metal oxide absorbent capable of absorbing sulfur oxides at a temperature of between about 100.degree. C. and 800.degree. C., and absorbing sulfur oxides with said metal oxide absorbent;(c) simultaneously, in the presence of a hydrocarbon cracking catalyst and at a temperature of between about 375.degree. C. and about 1,200.degree. C., cracking a hydrocarbon, regenerating the spent metal oxide absorbent and contacting the absorbent with steam to form hydrogen sulfide which can be separated from the cracked hydrocarbon and recovered as elemental sulfur.

Abstract: Carbonate waters from subterranean and other sources which are contaminated with dissolved sulfides contribute to environmental pollution. Herein the sulfides are removed without otherwise polluting the environment by conversion to insoluble metal sulfide reaction products separable from the carbonate waters with production of CO.sub.2 -free H.sub.2 S as a valuable byproduct. The dissolved sulfides are reacted with metal salt to form an insoluble sulfide reaction product from which the decontaminated carbonate water is separated, the reaction product is then decomposed by reacting with an aqueous acid comprising the negative radical of the metal salt thus producing H.sub.2 S essentially free of CO.sub.2 as a valuable product. The reformed metal salt is recycled. Conditions are provided for extracting ammonia contained in the carbonate water and for removing arsenic and/or mercury matter therefrom.

Abstract: Industrial waste gases containing sulfur dioxide, hydrogen fluoride, hydrochloric acid and sulfur trioxide are treated within a reaction tank in a first stage with a solution containing ammonium ions to increase the dew point of the gases. The gases are then cooled below the elevated dew point in a second stage below which a deflector system directs the gases along the wall of the reaction tank into a third stage where the gases are cooled by a spray mist of an ammonia mixture to form ammonium salts. The gases are then treated in a fourth stage at the bottom of the reaction tank with the solution containing ammonium ions to precipitate ammonium salts into a reservoir below the reaction tank. Purified waste gases are discharged into a cooler where a stripper removes entrained droplets of liquid before discharge into the atmosphere. The droplet size of the solution sprayed into the second stage is larger than the droplet size of the solution sprayed into the first stage.

Abstract: Hydrated alkali metal sulfides used to remove sulfur from fossil fuels to form alkali metal polysulfides which are recycled to alkali metal sulfides and elemental sulfur by thermal or thermal reduced pressure decomposition of the alkali metal polysulfides or by conversion of the hydrolysis products entirely by H.sub.2 S.

Abstract: A liquid or solid hydrocarbon is partially oxidized in the presence of steam and oxygen in a high temperature reducing flame zone to which at least sulfur dioxide is added to consume generated hydrogen and carbon monoxide formed in a second flame zone to form hydrogen sulfide as necessary for a Claus reaction. Elemental sulfur is thermally formed. The gas stream is rapidly cooled to prevent further reactions, then further cooled to condense sulfur. The resultant gas stream is passed to one or more Claus conversion zones where hydrogen sulfide and sulfur dioxide react to form sulfur.

Abstract: High temperature reducing gas is scrubbed of H.sub.2 S and other gaseous sulfur compounds at high temperature (>800.degree. K.) in a highly efficient regenerative process. The scrubbing is effected in at least two sequential stages. The first stage scrubbing medium is a molten salt comprised essentially of molten alkali carbonates, sulfides, and hydroxides. The second stage is optionally either a metallic melt comprised of copper or a second molten salt. The copper melt is regenerated with air. The salt melts are regenerated with steam and/or CO.sub.2. When two or more salt stages are used, they are regenerated stagewise countercurrently to the scrubbing sequence.

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 catalyst regenerator flue gas in an FCC system using a nonzeolitic cracking catalyst 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 nonzeolitic 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: Flue gas having a content of sulfur dioxide is passed upwardly through a scrubbing tower against a descending flow of recycled aqueous sodium aluminate-sodium hydroxide liquor. The sulfur dioxide in the gas is converted to sodium and aluminum sulfates and sulfites and the liquor removes any fly ash present in the gas. Underflow is continuously discharged from the tower and is sent to an evaporator for removal of excess water. Make-up solutions of sodium hydroxide, sodium sulfate and aluminum sulfate are added, as necessary. Carbonaceous reducing agent is added to the discharge from the evaporator. The mixture is continuously fed into a reducing furnace where the sulfates and sulfites are reduced to sulfides. The product of the furnace (molten sodium and aluminum sulfides) is charged into a continuous hydrolyzer. Hydrogen sulfide is evolved and collected, and, if desired, its sulfur content is converted to elementary sulfur. The underflow from the hydrolyzer is filtered.

Abstract: Certain impure steams, especially those from geothermal sources, are polluted with hydrogen sulfide, ammonia, carbon dioxide, other gases, and finely divided particulate solid matter in a form resembling dust or smoke. These contaminants reduce the efficiency of the steam as a heat transfer fluid, are detrimental to equipment utilizing steam as an energy source, and result in environmental pollution or expensive requirements for limiting the same. By the invention herein so polluted steam is selectively processed in the gaseous state upstream of said equipment to remove hydrogen sulfide therefrom, with or without removing other pollutants, to reduce environmental pollution from effluents thereof, to recover valuable materials therefrom, and to improve the utility of the steam as an energy source.

Abstract: In methods for combusting carbonaceous sulfur-containing fuels in a fluidized bed wherein the fluidized bed contains at least one calcium compound selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate and calcium bicarbonate to absorb sulfur oxides formed during the combustion of the carbonaceous fuel thereby producing calcium sulfoxy compounds having the formula CaSO.sub.x wherein x is 3 or 4, an improvement comprising (a) withdrawing a stream of fluidized bed solids containing said calcium sulfoxy compounds and mixing the fluidized bed solids and said calcium sulfoxy compounds with water to produce a slurry; (b) reacting the CaSO.sub.x compounds with NH.sub.3, H.sub.2 O and CO.sub.2 to produce water-soluble ammonium sulfoxy compounds such as NH.sub.4 (HSO.sub.x) where x is 3 or 4 and CaCO.sub.3 ; and (c) separating the ammonium sulfoxy compounds from the fluidized bed solids and CaCO.sub.3.

Abstract: A process for thermal activation of chalcopyrite-pyrite ore concentrates for activation of iron values in both chalcopyrite and pyrite constituents whereby said iron values can be selectively removed in a subsequent acid leach. Controlled oxidizing conditions are maintained in an oxidizing heating zone for removal of up to about 90% of total sulfur to be removed for conversion of pyrite and chalcopyrite to their acid-leachable forms, measured by a preferable oxidation of 10 to 15% of iron in the concentrate to ferromagnetic oxides, whereby remaining total sulfur to be removed is removed in a reducing zone with the assistance of a low H.sub.2 S/(H.sub.2 +H.sub.2 S) ratio by scavenging of H.sub.2 S by said oxides.

Abstract: A method for converting calcium sulfoxy compounds selected from the group consisting of CaSO.sub.x and Ca(HSO.sub.x).sub.2 and their hydrates wherein x is 3 or 4 into calcium carbonate, the method consisting essentially of; converting the Ca(HSO.sub.x).sub.2 compounds into CaSO.sub.x compounds by reacting the Ca(HSO.sub.x).sub.2 compounds with calcium carbonate in the presence of water, thereafter reacting the CaSO.sub.x compounds with ammonia and carbon dioxide in the presence of water to produce NH.sub.4 (HSO.sub.x) wherein x is 3 or 4 and calcium carbonate, thereafter separating the NH.sub.4 (HSO.sub.x) and calcium carbonate and reacting the NH.sub.4 (HSO.sub.x) with carbon to produce ammonia, hydrogen sulfide and carbon oxides.