Abstract: Hydrogen is produced from hydrogen sulfide by a 3-step, thermochemical process comprising:(a) contacting hydrogen sulfide with carbon dioxide to form carbonyl sulfide and water,(b) contacting the carbonyl sulfide produced in (a) with oxygen to form carbon monoxide and sulfur dioxide, and(c) contacting the carbon monoxide produced in (b) with water to form carbon dioxide and hydrogen.

Abstract: A process for removing sulfur dioxide from effluent gas and for recovering amphoteric components such as alumina from solid inorganic combustion byproducts.

Abstract: A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy.A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process.

Abstract: Catalytic process for reacting a sulphur-containing material such as elemental sulphur or hydrogen sulphide with an oxygen-containing gas to produce sulphur dioxide. The process and apparatus can be used to remove hydrogen sulphide from a gas. The process and apparatus may also be used to produce sulphur dioxide as a product which may be converted to SO.sub.3 and used, for example, to produce sulphuric acid.

Abstract: A process for the catalytic incineration of residual gases containing a low content of H.sub.2 S and/or SO.sub.2, organic compounds of sulfur such as COS, CS.sub.2, mercaptans and possibly vapor and/or vesicular sulfur, comprising a hydrogenation stage which transforms all the sulfur compounds into H.sub.2 S followed by a catalytic oxidation stage to transform H.sub.2 S into SO.sub.2.The catalyst used in the oxidation stage consists in a porous support, having a surface area of at least 5 m.sup.2 /g and containing, by weight, 50 to 100% of a product selected from the group comprising titanium or zirconium oxides, silica and zeolites, and 50 to 0% alumina, to which is associated one or several compounds of metals belonging to the group formed by Cu, Ag, Zn, Cd, Y, Lanthanides, V, Cr, Mo, W, Mn, Fe, Co, Rh, Ir, Ni, Pd, Pt, Sn and Bi. The use of such an oxidation catalyst leads to a practically quantitative yield of conversion of H.sub.2 S into SO.sub.

Abstract: Hydrogen sulfide is selectively oxidized in a gas stream containing at least 20 mol percent a carbon dioxide using an iron catalyst, preferably Fe.sub.2 O.sub.3 supported on a ceramic honeycomb support.

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: A catalytic cartridge internally heated is utilized as a SO.sub.3 decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO.sub.3 gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube being internally heated. In the axial-flow cartridge, SO.sub.3 gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and being internally heated. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.

Abstract: A gas containing oxygen, H.sub.2 S and sulfur oxides is desulfurized by contacting same with cerium oxide at a temperature of from about 350.degree.-600.degree. C. This invention is particularly useful for desulfurizing tail gas from a Claus plant. In a preferred embodiment the cerium oxide is supported on alumina and oxygen is present in the gas in an amount more than that stoichiometrically required to convert the H.sub.2 S and SO.sub.2 to cerium oxysulfate.

Abstract: A catalytic cartridge surrounding a heat pipe driven by a heat source is utilized as a SO.sub.3 decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO.sub.3 gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube surrounding the heat pipe. In the axial-flow cartridge, SO.sub.3 gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and surrounding the heat pipe. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.

Abstract: A process for removing sulfur dioxide from a mixture of gases and recovery of sulfur dioxide. The sulfur dioxide is first contacted in a scrubbing zone with an aqueous solution of a salt, M.sub.2 B, where M is a alkali metal cation, and B is a divalent anion derived a weak acid which has an ionization constant (pKa) value of at least 3.0. The pregnant scrubbing solution is then contacted with an amine acid salt, AHB, where A is an amine cationic group containing a hydrophobic subgroup of 8-45 carbons, and HB is a monovalent proton containing anion of a weak acid, to form by ion exchange, an amine hydrogen sulfite and an aqueous solution of alkali metal salt containing the anion HB. The sulfur bearing amine is heated to decompose the sulfite, releasing sulfur dioxide and a reduce sulfur content amine phase. The reduced sulfur content amine phase is contacted with the aqueous solution of alkali metal HB salt to regenerate the scrubbing salt solution of M.sub.2 B and the amine acid salt AHB.

Abstract: Compounds of formula I are useful in the separation of a gas such as oxygen, hydrogen, sulphur dioxide, alkenes and carbon monoxide from a fluid comprising the gas.Mn.sup.11 LX.sub.2 IIn formula I: L represents a monodentate ligand of formula IA and X is a species capable of existing as an anionPR.sup.1 R.sup.2 R.sup.3 IAwherein R.sup.1, R.sup.2 and R.sup.3 which may be identical or different represent substituted or unsubstituted alkyl, cycloalkyl or aryl groups or hydrogen and X represents --Cl, --Br, --I, --CN, --NO.sub.2, --NO.sub.3, --OH, --NCS or --NCO, provided that no more than two of the groups R.sup.1 R.sup.2 and R.sup.3 are substituted or unsubstituted aryl groups and that at least one of the groups R.sup.1, R.sup.2 and R.sup.3 is a substituted or unsubstituted alkyl, cycloalkyl or aryl group.

Abstract: The direct fluid contact heat exchange with H.sub.2 SO.sub.4 at about 330.degree. C. prior to high temperature decomposition at about 830.degree. C. in the oxygen release step of several thermochemical cycles for splitting water into hydrogen and oxygen provides higher heat transfer rates, savings in energy and permits use of cast vessels rather than expensive forged alloy indirect heat exchangers. Among several candidate perfluorocarbon liquids tested, only perfluoropropylene oxide polymers having a degree of polymerization from about 10 to 60 were chemically stable, had low miscibility and vapor pressure when tested with sulfuric acid at temperatures from 300.degree. C. to 400.degree. C.

Abstract: A two-stage process for the catalytic decomposition of H.sub.2 SO.sub.4 wherein H.sub.2 SO.sub.4 in vapor form is contacted in a first stage with a platinum group metal catalyst at temperatures between about 700.degree. K. and 970.degree. K. The platinum group metal catalyst is supported on a substrate of titania, barium sulfate, zirconia, silica, zirconium silicate or a mixture thereof, and at least about 40 percent of the H.sub.2 SO.sub.4 is decomposed to SO.sub.2. Vapors from the first stage enter a second stage where they contact a copper oxide and iron oxide catalyst at a temperature above 970.degree. K. The second stage catalyst is supported on a substrate of barium sulfate, zirconium oxide or titanium oxide.

Abstract: A process for purifying a gas containing hydrogen sulfide, wherein said gas is admixed with oxygen and contacted with a carbon mass of specific surface higher than 50 m2/g and containing at least one oxide and/or sulfate of iron and/or copper, at a temperature from 20.degree. to 170.degree. C., the operating conditions being so selected as to avoid a substantial oxidation of said mass and said mass being periodically regenerated by heating to 200.degree.-300.degree. C. in the presence of oxygen, the regenerating conditions being such as to avoid a substantial oxidation of the carbon mass.

Abstract: A continuous regenerative process for desulfurizing a hot reducing gas is disclosed. The gas is scrubbed by a sorbent containing MnO and Mn.sub.3 O.sub.4. The spent sorbent is regenerated by reacting the MnS with an excess of Mn.sub.3 O.sub.4, contained in oxidized sorbent. The oxidized sorbent is obtained by reacting part of the regenerated sorbent with air. In the regenerator the gaseous oxygen partial pressure is maintained below 10.sup.-6 atmospheres which allows the SO.sub.2 partial pressure to be maintained above 1 atmosphere without causing sulfation.

Abstract: A gas containing carbon oxysulfide or carbon disulfide is passed in admixture with oxygen through a catalyst formed of a carrier, vanadium oxide and silver, the proportion of iron oxide, if any, being lower than 1% by weight. The amount of vanadium oxide may be 0.5 to 10% by weight and that of silver 0.05 to 4% by weight.

Abstract: A refining process of a hot gas such as coal gas containing hydrogen sulfide and ammonia comprises steps of contacting the hot gas with a first catalyst comprising iron oxide to remove hydrogen sulfide, and then contacting the hot gas with a second catalyst comprising reduced iron made by reducing iron oxide prior to introducing the hot gas into the catalyst to remove ammonia. The refining process further includes steps of temperature adjustment of the gas directing to the first and second catalyst and the removal of hydrogen sulfide remaining in the hot gas after the removal of the ammonia with a third catalyst comprising iron oxide.

Abstract: An integrated method for the derivation of useful energy from steam containing both hydrogen sulfide and an alkaline acting component, such as ammonia, while substantially reducing the emission of sulfur-containing compounds to the atmosphere. Pretreatment of the steam to selectively remove the alkaline acting components results in the concentration of hydrogen sulfide in the uncondensed vapor as the steam is condensed during energy derivation. The uncondensed vapor is separated from the steam condensate and then is treated to produce an environmentally acceptable vent gas.

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: Sulfur dioxide is removed from a gas stream by contacting the gas with an aqueous solution containing sulfite anion, magnesium cation, and one or more other cations whose sulfite salts are more soluble than magnesium sulfite. The contacting solution is regenerated with magnesium oxide or hydroxide and then recycled.

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: Ammonium imidodisulfate and ammonium sulfamate may be converted to sulfur dioxide and ammonia by heating them with a reducing agent or a catalyst in a bath of molten ammonium sulfate and ammonium bisulfate. The reducing agent is sulfur or a sulfur compound and the catalyst is selected from Mo, W, Cu, Fe, Co, Cr, Mn and Ni.

Abstract: Dolomite which has been used to remove sulfur and/or sulfur-containing compounds from gases by chemical reactions therewith is regenerated by passing through the spent dolomite an oxidizing gas selected from oxygen, CO.sub.2 and H.sub.2 O at temperatures between about 1500.degree. F. and the temperature at which the dolomite becomes unreactive.

Abstract: A process for removing sulfur dioxide from a mixture of gases and converting the removed SO.sub.2 to elemental sulfur. The sulfur dioxide is first contacted in a scrubbing zone with a scrubbing agent which is an aqueous solution of an alkali metal salt of a weak acid which has an ionization constant (pKa) value of at least 3.5. The pregnant scrubbing solution is then contacted with an organic transfer reactant which is a water immiscible, water insoluble amine salt to effect a transfer reaction by which the sulfite ions are transferred to the non-aqueous phase by way of an ion exchange reaction. The sulfur bearing, non-aqueous phase is next heated to decompose the sulfite, releasing sulfur dioxide and a water immiscible, water insoluble amine-bearing compound. The amine-bearing compound is next contacted with the alkali metal salt scrubbing solution from the transfer step.

Abstract: Sulfur dioxide is removed from waste gases such as stack gases by contacting the gas stream with free tertiary amines having basic strengths greater than about pK 5 to form a coordinate covalent complex of the amine and the sulfur dioxide. The sufficiently stable complex is than thermally regenerated to liberate the sulfur dioxide in one stream, to provide the residual gases in another stream, and to provide the regenerated tertiary amine for collection and reuse in a subsequent sulfur dioxide cleanup step. The coordinate covalent complex reacts with even very small concentrations of sulfur dioxide to effectively reduce the sulfur dioxide to detectable zero levels. The presence of carbon dioxide in waste gas streams does not interfere with the efficient cleanup because the selected tertiary amine does not react with the carbon dioxide.

Abstract: Sulfur dioxide is removed from a sulfur dioxide-containing gas mixture by contacting the gas mixture with a monoolefin or diolefin.

Abstract: A process for the chlorination of a material containing iron and titanium chemically combined with oxygen, comprising feeding the material to be chlorinated, in particulate solid form, into a reaction bed of solids containing ferrous chloride, and reacting it within that bed, at a temperature below the melting point of ferrous chloride, with a controlled amount of chlorine in the presence of sulphur in free or combined form, to produce solid ferrous chloride, titanium chloride, which is volatile at a temperature of operation, and sulphur dioxide, as the principal products of the process.

Abstract: Gases containing elemental sulfur are purified therefrom by contact with sulfur trioxide in oleum; additionally the gas may be purified by carbonaceous material. In one embodiment, shown in the drawing, the process is used to remove elemental sulfur from sulfur dioxide produced by reaction of molten sulfur (3) with sulfur trioxide. A portion of the sulfur trioxide is by-passed (6) and introduced into the overhead line (5) of the sulfur dioxide reactor (4). The gases are purified in a second reactor (11) containing a pool of oleum (10).

Abstract: A process for the conversion of H.sub.2 S to SO.sub.2 in a feed gas containing H.sub.2 S is effected by oxidation with air or oxygen at temperatures between 300.degree. and 900.degree. F. The oxidation is conducted in the presence of an extremely stable oxidation catalyst comprising an oxide and/or sulfide of vanadium supported on a non-alkaline porous refractory oxide. The preferred catalyst comprises between 5 and 15 wt.% V.sub.2 O.sub.5 on hydrogen mordenite or alumina. Hydrogen, carbon monoxide, light hydrocarbons, and ammonia present in the feed gas are not oxidized. The invention is especially contemplated for use in treating waste gases from geothermal steam power plants.

Abstract: A process for the conversion of H.sub.2 S to SO.sub.2 in a feed gas containing H.sub.2 S is effected by oxidation with air or oxygen at temperatures between 300.degree. and 900.degree. F. The oxidation is conducted in the presence of an extremely stable oxidation catalyst comprising an oxide and/or sulfide of vanadium supported on a non-alkaline porous refractory oxide. The preferred catalyst comprises between 5 and 15 wt. % V.sub.2 O.sub.5 on hydrogen mordenite or alumina. Hydrogen, carbon monoxide, light hydrocarbons, and ammonia present in the feed gas are not oxidized. The invention is especially contemplated for use in treating waste gases from geothermal steam power plants.

Abstract: Hydrocarbons are formed of coal and water. The water is converted or dissociated separately into hydrogen and oxygen in a first chemical reactor by thermochemical and/or electrolytic processing. The resulting hydrogen is then reacted with the coal in a second reactor to produce the hydrocarbons. Residual carbon from the second reactor is reacted in a third reactor with oxygen derived from the first reactor to produce carbon monoxide. The carbon monoxide is reacted with residual hydrogen from the second reactor or hydrogen from the first reactor to produce additional hydrocarbons. The energy for the endothermic and/or electrolytic processing in the reactors and for auxiliary equipment of the apparatus is supplied by a very high-temperature, gas-cooled, nuclear reactor by heat interchange with the cooling gas, helium. The cooling gas operates through heat-exchange means which isolates the cooling gas from the processing apparatus.

Abstract: The process of reacting a metallic halide (which metal is sodium, potassium or calcium) with sulfur trioxide including dispersing the metallic halide in the presence of an excess of sulfur trioxide or sulfur dioxide, as a dispersant, to enable handling the mixture as a slurry, completing the reaction to form the desired metallic halogen sulfonate, decomposing the metallic halogen sulfonate before or after an intermediate step to remove excess sulfur trioxide and sulfur dioxide, using combustion of sulfur to supply the heat to vaporize excess sulfur trioxide and sulfur dioxide present, and to decompose the metallic halogen sulfonate to yield the halogen, sulfur dioxide, and the sulfate of the metal, separating the metallic sulfate from the gaseous products, and separating the halogen from the sulfur trioxide and sulfur dioxide in the gaseous products by extractive distillation, or alternately treating organic material under anhydrous conditions with the metallic halogen sulfonate or its decomposition products,

Abstract: A catalyst/adsorbent for sulfur dioxide from waste gases, via oxidation thereof to sulfur trioxide, comprising vanadium oxide supported on activated carbon, promoted by nickel sulfate or potassium sulfate, or preferably by both.

Abstract: A process for steam stripping sulfur dioxide from a buffered aqueous solution in which it is absorbed in a flue gas desulfurization process is carried out at pressure greater than atmospheric. The process of pressure stripping of sulfur dioxide surprisingly results in increased steam economy as compared to stripping at atmospheric pressure and yields sulfur dioxide vapor which can be directly condensed to a liquid product with ordinary cooling water, eliminating the need for drying, refrigeration or compression operations. The high temperatures corresponding to high steam pressures enable economical use of stripping vessel overheads for preheating operations also. Stripping at pressures of 50 to 65 psig results in steam requirements which are only one-third to one-half of that at atmospheric pressure stripping. At the high pressures lower gas flow rates permit the use of more compact stripping equipment.

Abstract: Hydrogen is produced from water by first reacting I.sub.2, SO.sub.2 and H.sub.2 O to make hydrogen iodide and sulfuric acid. A substantial molar excess of SO.sub.2 and I.sub.2 in the reaction zone creates a lighter sulfuric acid-bearing phase and a heavier polyiodic-acid-bearing phase. The heavier phase is separated, degassed and then contacted with phosphoric acid to permit distillation of HI of low water content and recovery of I.sub.2 as a separate fraction. Hydrogen is recovered from HI vapor, as by thermal decomposition.

Abstract: A novel catalyst for converting sulfurous anhydride to sulfuric anhydride and vice versa, which catalyst comprises iron, copper, and at least one alkali metal selected from among sodium and potassium, the catalyst simultaneously having good activity at 600.degree. C and withstanding temperatures up to 850.degree. C without degradation.

Abstract: A feed gas containing one or more components selected from the class consisting of H.sub.2 S, SO.sub.2, SO.sub.3, COS, CS.sub.2, light mercaptans, and sulfur vapor is desulfurized by (a) hydrogenating and hydrolyzing essentially all non-H.sub.2 S sulfur components to H.sub.2 S, (b) oxidizing most of the H.sub.2 S in the resulting product gas to sulfur, and removing the latter by condensation, (c) oxidizing the residual H.sub.2 S to SO.sub.2, (d) absorbing essentially all the SO.sub.2 in an aqueous ammonia solution, (e) passing a portion of the SO.sub.2 -containing ammonia solution to step (a), and (f) discharging from step (d) a purified product gas essentially free of sulfur components.A feed gas, such as a stack gas, which contains only SO.sub.2 and SO.sub.3 components to be removed therefrom, may be treated in alternative embodiments of the invention involving the passage of all or a major proportion of the feed gas directly to absorption step (d).

Abstract: A process for eliminating sulphur oxides from combustion exhaust gases, comprising the steps of dividing the combustion exhaust gases into a first stream and a second stream, and passing the first stream through a first activated carbon bed which was previously washed with water, thereby drying the activated carbon, cooling the first stream, and removing a substantial portion of sulphur oxides from the first stream by adsorption. The treated first stream is mixed with the second stream and together passed through a second activated carbon bed which was previously dried, thereby removing sulphur oxides by dry adsorption. A third activated carbon bed which was previously used in the dry adsorption step is washed with water, removing the previously adsorbed sulphur oxides therefrom. Each of the first, second and third activated carbon beds are cyclically treated by the drying, dry adsorption and washing steps.

Abstract: Anhydrous liquid sulfur dioxide is recovered from environmentally unsuitable vapor or liquid streams comprising water, sulfur dioxide and carbon dioxide. The vapor streams are fed into an absorption zone and contacted with a lean liquid water stream. A resulting sulfur dioxide rich water stream is passed into a first fractionation column utilized in part as the stripper column which produces the lean water stream. A sidecut stream removed above the feed point is passed into a second fractionation column, and the overhead vapor of the first column is subjected to two stages of partial condensation to aid carbon dioxide rejection. Anhydrous sulfur dioxide is removed as a liquid sidecut of the second column, and the net overhead vapor of the second column is preferably passed into the overhead system of the first column after a partial condensation.

Abstract: Removal of sulfur dioxide from an aqueous solution containing the same is effected by subjecting the solution to electrodialytic water splitting. In particular SO.sub.2 is removed from dilute gas streams by means of alkaline solution scrubbing, regeneration of the scrubbing solution and liberation of concentrated SO.sub.2 by means of a membrane water splitter. Waste sulfate produced in the process may be converted to sulfuric acid in a separate membrane water splitter or otherwise processed by conventional means.

Abstract: A process is provided for reducing the requirement of fresh chemicals without increasing emissions in the pulping of cellulosic material with alkaline sodium- and sulfur-containing-sulfate pulping liquor, which comprises evaporating and burning spent sulfate pulping liquor to obtain a smelt; dissolving the resulting smelt in water to form a sodium-sulfide-sodium carbonate-containing solution green liquor; regenerating pulping white liquor containing sodium sulfide and sodium hydroxide from said green liquor; and recirculating said regenerated white liquor to the pulping stage; oxidizing at least one of the resulting green and white liquors to form sodium thiosulfate therein; reacting the oxidized liquor with residual acid liquor, from the manufacture of chlorine dioxide by reduction of an alkali metal chlorate solution, to convert thiosulfate to sulfur dioxide and sulfur; removing and recovering formed sulfur dioxide; and returning the residual liquor, freed from sulfur dioxide, to the pulping.

Abstract: A process for the conversion of H.sub.2 S to SO.sub.2 is a feed gas containing H.sub.2 S is effected by oxidation with air or oxygen at temperatures between 300.degree. and 900.degree. F. The oxidation is conducted in the presence of an extremely stable oxidation catalyst comprising an oxide and/or sulfide of vanadium supported on a non-alkaline porous refractory oxide. The preferred catalyst comprises between 5 and 15 wt.% V.sub.2 O.sub.5 on hydrogen mordenite or alumina. Hydrogen, carbon monoxide and light hydrocarbons present in the feed gas are not oxidized. The invention is especially contemplated for use in treating waste gases from geothermal steam power plants.

Abstract: An energy conversion, conveyance and utilisation system, particularly for providing process heat in industrial plants, which makes use of a source of heat such as a nuclear reactor to dissociate sulfur trioxide according to the reaction:2SO.sub.3 .revreaction.2SO.sub.2 + O.sub.2,the dissociation products being conveyed through a pipeline to a remote utilization station where the heat of recombination is utilized, the resulting sulfur trioxide being returned through the pipeline to the reactor site. The pipeline incorporates separate pipes in which the sulfur dioxide and sulfur trioxide are conducted in liquefied form, surrounded by a duct in which the gaseous oxygen flows.

Abstract: Hydrogen is thermochemically produced from water in a cycle wherein a first reaction produces hydrogen iodide and H.sub.2 SO.sub.4 by the reaction of iodine, sulfur dioxide and water under conditions which cause two distinct aqueous phases to be formed, i.e., a lighter sulfuric acid-bearing phase and a heavier hydrogen iodide-bearing phase. After separation of the two phases, the heavier phase containing most of the hydrogen iodide is treated, e.g., at a high temperature, to decompose the hydrogen iodide and recover hydrogen and iodine. The H.sub.2 SO.sub.4 is pyrolyzed to recover sulfur dioxide and produce oxygen.

Abstract: A process for purifying a hydrogen sulfide containing gas, which comprises absorbing said hydrogen sulfide onto a mass comprising zinc oxide, alumina and a group II A metal oxide, a large proportion of the group II A metal oxide being in the form of aluminate or silicoaluminate; then regenerating the mass by passing an oxygen containing gas therethrough.

Abstract: A process for the conversion of H.sub.2 S to SO.sub.2 in a feed gas containing H.sub.2 S is effected by oxidation with air or oxygen at temperatures between 300.degree. and 900.degree. F. The oxidation is conducted in the presence of an extremely stable oxidation catalyst comprising an oxide and/or sulfide of vanadium supported on a non-alkaline porous refractory oxide. The preferred catalyst comprises between 5 and 15 wt.% V.sub.2 O.sub.5 on hydrogen mordenite or alumina. Hydrogen, carbon monoxide and light hydrocarbons present in the feed gas are not oxidized. The invention is especially contemplated for use in treating waste gases from geothermal steam power plants.

Abstract: Sulfur dioxide is separated from an aqueous solution containing the same by subjecting the stream to electrodialytic water splitting. In particular a novel method for removing SO.sub.2 from dilute gas streams by means of alkaline solution scrubbing, regeneration of the scrubbing solution and liberation of concentrated SO.sub.2 effected by means of a two-compartment membrane water splitter is provided. Optionally, waste sulfate produced in the process may be converted to sulfuric acid in a separate membrane water splitter or otherwise processed by conventional means.

Abstract: Production of an activated type alumina from aluminum dross by digestion with water, preferably pressurized. The peculiar properties associated with trace compounds present in the product make it useful for the recovery of noxious effluents from furnacing processes, including those burning fossil fuels and those used for smelting both aluminum and steel, wherein the alumina beneficially incorporates in the metallurgical flux.

Abstract: Combustible carbonaceous and sulfur-containing wastes, especially waste liquors of cellulose plants, are burnt with a combustion-sustaining gas having a greater oxygen concentration than atmospheric oxygen (e.g. pure oxygen) and the gaseous products of the combustion are subjected to scrubbing to remove carbon oxides. The process is carried out under pressure and preferably with two-stage combustion so that carbon monoxide produced in an initial stage can be burnt further in the combustion chamber of a gas turbine to drive the latter and generate at least part of the power necessary to operate the compressor for the oxygen-rich gas.