Abstract: The present invention provides a process for removing ammonia as an aqueous salt solution from an acid gas comprising ammonia and hydrogen sulfide. A strong acid, such as sulfuric acid, is used as a scrubbing agent to convert ammonia to an ammonium salt. Control of pH and stripping in combination with reboiler or evaporators reduces hydrogen sulfide concentration. The ammonium salt is produced as an aqueous solution, which may crystallized to form a solid product. The ammonium salt solution or solid may be used as a fertilizer.

Abstract: The present invention comprises a method of treating an off-gas stream from a refining process to remove sulfur compounds. A portion of the off-gas stream containing hydrogen sulfide is injected at the front end of the thermal reactor and in at least one other location downstream of the thermal reactor. A ratio of hydrogen sulfide to sulfur dioxide at the outlet of the thermal reactor is less than the stoichiometric requirement. The ratio is adjusted downstream of the thermal reactor so that a ratio of hydrogen sulfide to sulfur dioxide is maintained substantially in excess of the stoichiometric requirement for a Claus reaction. The tail gas, containing hydrogen sulfide but virtually no sulfur dioxide, is treated by a process including removal of water and introducing sulfur dioxide into the tail gas in a stoichiometricly balanced quantity and processing the tail gas in a Claus reactor.

Abstract: A compact sulfur recovery system is disclosed which comprises a primary structure including a catalytic partial oxidation reaction zone, a first temperature-control zone, a first Claus catalytic reaction zone, a second temperature-control zone, a first liquid sulfur outlet, and a first effluent gas outlet. In some embodiments, a secondary structure follows the primary structure and comprises a second Claus catalytic reaction zone, a third temperature-control zone, a second liquid sulfur outlet, and a second effluent gas outlet. One or more components of the system employ heat transfer enhancement material in the temperature-control zones, and one or more components deter accumulation of liquid sulfur in the Claus catalytic reaction zones.

Abstract: Disclosed is a method for treating a feed gas stream rich in hydrogen sulfide by partially combusting the feed gas stream rich in hydrogen sulfide with an oxygen-enriched gas in a Claus reaction furnace to produce to a combustion reaction product stream containing sulfur. The combustion reaction product stream is split into a recycle stream and a treatment stream and the recycle stream directed back into the Claus reaction furnace, without first condensing sulfur out of the recycle stream, while the treatment stream is directed into a condenser to condense sulfur out of the treatment stream.

Abstract: A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

Abstract: A hydrocarbon gas containing H2S, mercaptans and CO2 is fed to an absorption plant operated at a pressure of 20 to 80 bar and supplied with a selective solvent, a solvent stream loaded with H2S and a roughly desulfurized gas stream are withdrawn, the H2S loaded solvent stream is charged to a regeneration plant and the roughly desulfurized gas stream is charged to an absorption and regeneration plant operated at a pressure of 20 to 80 bar, a large first gas stream of H2S and CO2 and an unloaded solvent stream are withdrawn from the absorption regeneration plant, and the large first gas steam of H2S and CO2 is supplied to a Claus plant, and a valuable hydrocarbon gas stream is withdrawn from the absorption and regeneration plant.

Abstract: Apparatus and process for recovering elemental sulfur from a H2S-containing waste gas stream are disclosed. The apparatus preferably comprises a first reaction zone for carrying out the catalytic partial oxidation of H2S, a second reaction zone for the catalytic partial reduction of any incidental SO2 produced in the first reaction zone, and a cooling zone including a sulfur condenser. According to a preferred embodiment of the process, a mixture of H2S and O2 contacts a catalyst in the first reaction zone very briefly (i.e, less than about 200 milliseconds) producing primarily S0 and H2O. Some SO2 is also present in the first stage product gas mixture. A reductant gas (e.g. CO, or CH4 or natural gas) is fed together with the first stage product gas mixture to a second catalytic reaction zone where the partial reduction of the SO2 component to elemental sulfur and CO2 is carried out.

Abstract: A process and system for producing synthesis gas by a SPOC® enhanced catalytic partial oxidation process is disclosed. Light hydrocarbons in a H2S-containing feed gas are partially oxidized to produce hydrogen and carbon monoxide over a catalyst that simultaneously oxidizes the H2S to produce elemental sulfur. A reaction in which H2S is partially oxidized to elemental sulfur and water takes place instead of a secondary reaction in which a portion of the light hydrocarbon feed is combusted to form CO2 and water. An increase in yield and selectivity for CO and H2 products results, and readily recoverable elemental sulfur is also produced.

Abstract: A multistage oxygen-added catalytic partial oxidation process and apparatus for converting H2S in an acid gas stream to elemental sulfur and water are disclosed. Each staged addition of oxygen or air at the top of the catalyst bed and at points along the catalyst bed maintain oxygen-limited H2S catalytic partial oxidation conditions whereby incidental SO2 production is minimized.

Abstract: A process for removing hydrogen sulfide, other sulfur-containing compounds and/or sulfur and mercury from a gas stream contaminated with mercury, hydrogen sulfide or both. The method comprises the step of selective oxidation of hydrogen sulfide (H2S) in a gas stream containing one or more oxidizable components other than H2S to generate elemental sulfur (S) or a mixture of sulfur and sulfur dioxide (SO2). The sulfur generated in the gas stream reacts with mercury in the gas stream to generate mercuric sulfide and sulfur and mercuric sulfide are removed from the gas stream by co-condensation.

Abstract: A method is provided for removal of sulfur gases and recovery of elemental sulfur from sulfur gas containing supply streams, such as syngas or coal gas, by contacting the supply stream with a catalyst, that is either an activated carbon or an oxide based catalyst, and an oxidant, such as sulfur dioxide, in a reaction medium such as molten sulfur, to convert the sulfur gases in the supply stream to elemental sulfur, and recovering the elemental sulfur by separation from the reaction medium.

Abstract: A method for partially oxidizing, in a Claus furnace, at least one gas containing hydrogen sulfide and ammonia with at least one gas rich in oxygen. The residual ammonia content at the outlet of the furnace is measured with a laser diode. Based upon this measurement, the flow rates of the ammonia containing gases and the oxygen rich gases may be modified to obtain the desired residual ammonia content.

Abstract: The reactor is comprised of a body, a tubular ceramic porous membrane element placed coaxially inside it to remove the hydrogen, and a catalyst for the thermal breakdown of the hydrogen sulfide into sulfur and hydrogen, wherein said catalyst has been deposited directly on the tubular ceramic porous membrane element in the form of a layer. The reactor is applicable for treating gases containing hydrogen sulfide.

Abstract: The present invention relates to a process for regenerating an at least partly reduced catalytic redox solution. The solution includes at least one polyvalent metal chelated by a chelating agent and is circulated in at least one regeneration zone while an oxygen-containing gas is injected into the regeneration zone. The process includes measuring a concentration of oxygen dissolved in a regeneration zone effluent. The process also includes adjusting a flow rate of the at least partly reduce catalytic redox solution entering the at least one regeneration zone and/or an oxygen-containing gas entering the regeneration zone in response to a measured concentration of oxygen, until a concentration of oxygen in the regeneration zone effluent is less than 20% of an amount of oxygen dissolved in water saturated with oxygen. Thus, degradation of the chelating agent in the catalytic redox solution is minimized.

Abstract: The invention is directed to a process for the recovery of sulphur from a hydrogen sulphide containing gas, which process comprises; i) oxidizing part of the hydrogen sulphide in a gaseous stream with oxygen or an oxygen containing gas in an oxidation stage to sulphur dioxide; ii) reacting the product gas of this oxidation stage in at least two catalytic stages, in accordance with the Claus equation: 2 H2S+SO2→2 H2O+3/n Sn; iii) catalytically reducing SO2 in the gas leaving the last of said at least two catalytic stages, wherein the catalytic reduction takes place in a catalyst bed downstream from the last Claus catalytic stage.

Abstract: A process is described for the elimination of hydrogen sulfide from gas mixtures by catalytic oxidation over activated carbon catalyst which converts the hydrogen sulfide to elemental sulfur and water, the former being sorbed by the activated carbon while the latter is transported with the gas mixture and may be removed by known dehydration processes. The above oxidative process is conducted at elevated temperatures and pressures and with sufficient residence time to assure virtually complete conversion of the hydrogen sulfide with minimal production of by-product sulfur dioxide. Traces of heavy hydrocarbons in the feed gas mixture which may reduce the life of the catalyst and the quality of the sulfur product may be removed by cryogenic means or by sorption on an activated carbon guard bed.

Abstract: The invention relates to catalysts and catalytic methods for selective oxidation of hydrogen sulfide (H2S) in a gas stream containing one or more oxidizable components other than H2S to generate sulfur dioxide (SO2), elemental sulfur (S) or both without substantial oxidation of the one or more oxidizable components other than H2S. The catalysts and methods herein are useful, for example, for the selective oxidation of H2S to SO2, sulfur or both in the presence of hydrocarbons, hydrocarbon oxygenate, sulfur-containing organic compounds, aromatic hydrocarbons, aliphatic hydrocarbons, carbon dioxide, hydrogen or carbon monoxide.

Abstract: Sour gas containing hydrogen sulphide has hydrogen sulphide absorbed therefrom in an absorbent in a vessel 4. A hydrogen sulphide rich gas stream is formed by desorbing hydrogen sulphide from the absorbent in a vessel 12. The resulting hydrogen sulphide rich gas stream is partially burned in a furnace 32. Resulting sulphur dioxide reacts therein with residual hydrogen sulphide to form sulphur vapor which is extracted in a condenser 44. Residual sulphur dioxide and sulphur vapor are reduced to hydrogen sulphide in catalyst stage 54 of a reactor 50. Water vapor is removed from the resulting reduced gas stream by direct contact with water in a quench tower 60. At least part of the resulting water vapor depleted gas stream is sent to the vessel 4 with the incoming sour gas stream.

Abstract: A process and system is disclosed for removing sulfur from tail-gas emitted from a Claus sulfur recovery process. First, the tail-gas is oxidized so as to convert sulfur therein to sulfur oxides. Oxidized tail-gas is directed into an absorber where a solid absorbent absorbs substantially all the sulfur oxides thereon. After allowing sufficient time for a desired amount of sulfur oxides to be absorbed, absorption is ceased. Next, the solid absorbent containing the absorbed sulfur oxides is contacted with a reducing gas so as to release an off gas containing hydrogen sulfide and sulfur dioxide. Upon releasing sulfur from the solid absorbent, the solid absorbent is regenerated and redirected into the absorber. Sulfur in the off gas emitted by regeneration is concentrated to an extent sufficient for use within a Claus sulfur recovery process for conversion to elemental sulfur.

Abstract: In the desulfurization of a gaseous feed containing hydrogen sulfide, comprising contacting the gaseous feed with a catalytic solution containing a chelated polyvalent metal under suitable conditions for oxidation of the hydrogen sulfide to elementary sulfur and concomitant reduction of the chelated polyvalent metal from a higher oxidation level to a lower oxidation level, recovering a gaseous effluent substantially freed from hydrogen sulfide, and a catalytic solution at least partly reduced and containing elementary sulfur, separating the solid elementary sulfur from the reduced catalytic solution, and regenerating the reduced catalytic solution by contacting the catalytic solution with a gas containing oxygen by means of an ejector.

Abstract: A process and system for producing synthesis gas by a SPOC™ enhanced catalytic partial oxidation process is disclosed. A reaction in which H2S is partially oxidized to elemental sulfur and water takes place instead of a secondary reaction in which a portion of the light hydrocarbon feed is combusted to form CO2 and water. An increase in yield and selectivity for CO and H2 products results, and readily recoverable elemental sulfur is also produced.

Abstract: A process intended for desulfurization of a gaseous feed containing hydrogen sulfide, includes at least the following stages: a) contacting the gaseous feed with a catalytic solution containing at least one polyvalent metal chelated by at least one chelating agent, under suitable conditions for oxidation of the hydrogen sulfide to elemental sulfur and concomitant reduction of the polyvalent metal from a higher oxidation level to a lower oxidation level, b) recovering on the one hand a gaseous effluent substantially freed from hydrogen sulfide and, on the other hand, the catalytic solution at least reduced and containing elemental sulfur, and c) recycling at least a fraction F1 of the catalytic solution at least reduced and containing solid elemental sulfur to absorption stage a) so as to reduce the number of sulfur grains of very small size.

Abstract: A method, system and catalysts for improving the yield of syngas from the catalytic partial oxidation of methane or other light hydrocarbons is disclosed. The increase in yield and selectivity for CO and H2 products results at least in part from the substitution of H2S partial oxidation to elemental sulfur and water for the combustion of light hydrocarbon to CO2 and water.

Abstract: Disclosed is a method in which hydrogen sulfide-containing liquid sulfur is introduced into a containment vessel to partially fill the containment vessel and create a hydrogen sulfide-containing liquid sulfur phase and a hydrogen sulfide-containing vapor phase. A portion of the hydrogen sulfide-containing liquid sulfur phase is then treated to produce a liquid sulfur-containing phase and a gaseous hydrogen sulfide-containing phase, such that the gaseous hydrogen sulfide-containing phase has a pressure of at least about 60 psig. A portion of the hydrogen sulfide-containing vapor phase is then withdrawn from the containment vessel using at least one eductor driven by a motive fluid, where the motive fluid is the gaseous hydrogen sulfide-containing phase from the container vessel. The hydrogen sulfide-containing waste gas stream exiting the eductor is then treated to reduce the hydrogen-sulfide content of the waste gas.

Abstract: A method is provided for increasing the lifetime of Stretford solution by reducing or eliminating the generation of undesirable thiosulfate salts. The method has three major aspects. First, thiocyanate is added to the Stretford solution. Second, the concentration of sodium sulfate in the solution is maintained at a level below about 100 g/l. Third, the solution should contain little or no thiosulfate at the start of operations. It has been found that little or no thiosulfate is generated when the Stretford unit is operated under these conditions. The concentration of sodium sulfate in the solution is maintained at a level below about 100 g/l by removing sodium sulfate from the solution by cooling a slipstream of the solution to precipitate the sodium sulfate as Glauber's salt.

Abstract: A process is provided for the removal of hydrogen sulfide out of a gaseous stream (22), such as a natural gas, by contacting the hydrogen sulfide containing gas with a sorbing liquid (26) containing a tertiary amine so that the hydrogen sulfide is sorbed into the liquid in absorber (11) and transferring the sorbing liquid/hydrogen sulfide mixture to a reactor (15) where the tertiary amine promotes the conversion of the hydrogen sulfide into polysulfide via reaction with sulfur; transferring the polysulfide solution from the reactor (15) to a regenerator (10) where polysulfide is converted into elemental sulfur via reaction with air (9); transferring at least a portion of the solution (25) containing elemental sulfur, as well as sulfate and thiosulfate species, into a mixture (36) where it is contacted with gaseous ammonia which reacts with the sulfate and thiosulfate species to produce ammonium sulfate and ammonium thiosulfate which are removed from the solution while the remaining portion of solution (25) is

Abstract: A process and apparatus for recovering sulphur from a combustible gas stream comprising hydrogen sulphide, air, commercially pure oxygen or oxygen-enriched air. The combustible gas stream are fed to a burner which fires into an elongate furnace. A longitudinally extending flame is created which as a relatively oxygen-poor endothermic hydrogen sulphide dissociation region, and a relatively oxygen-rich, intense hydrogen sulphide combustion region. Residual hydrogen sulphide reacts with sulphur dioxide formed by the combustion to produce sulphur vapor. The furnace has an aspect ratio of about 8:1. The flame diverges from its root to occupy at its maximum cross-sectional area at least about 80% of the cross-sectional area of the furnace interior coplanar therewith.

Abstract: High quality hydrophilic sulfur is recovered from a biologial conversion zone in which a sulfur containing compound such as a sulfide is converted to elemental sulfur. The sulfur is rendered hydrophilic due to the fine particle size and attachment of biomass to the particles. The sulfur is recovered as an undamaged agglomerate powder after being processed in at least two stages of purification.

Abstract: A feed gas stream containing hydrogen sulphide is subjected in a furnace 6 to reactions in which part of the hydrogen sulphide is burned to form sulphur dioxide, and is which the sulphur dioxide reacts with residual hydrogen sulphide to form sulphur vapor. The sulphur vapor is condensed from the gas stream exiting the furnace 6 in a sulphur condenser 16. Residual sulphur dioxide is reduced back to hydrogen sulphide by hydrogen in a reactor 22. Water vapor is removed from the reduced gas in a quench tower 28 to form a water vapor-depleted gas stream. One part of the water vapor-depleted gas stream is sent to an adsorber vessel 30 in which hydrogen sulphide is absorbed in an absorbent. The resulting hydrogen sulphide-depleted gas stream is vented from the vessel 30 as a purge stream. Another part of the water vapor-depleted gas stream and a hydrogen sulphide-rich gas formed by desorbing hydrogen sulphide from the absorbent in a vessel 38 are returned as recycle streams to the furnace 6.

Abstract: A process is set forth for improving an oxygen-enriched Claus plant by recycling through an ejector effluent from the first condenser back to the reaction furnace to moderate oxygen induced high temperatures and thus allow additional oxygen-enrichment and attendant throughput in the Claus plant.

Abstract: Sulphur is recovered from a first gas stream comprising hydrogen sulphide and at least 50% by volume of ammonia and from a second gas stream comprising hydrogen sulphide but essentially no ammonia, the first gas stream, the second gas stream, and combustion supporting gas comprising at least one stream of essentially pure oxygen or oxygen-enriched air are fed to a single combustion zone or a plurality of combustion zones in parallel with each other without premixing of first gas stream or the second gas stream with oxygen or air, and creating in the or each combustion zone at least one region in which thermal cracking of ammonia takes place, and taking from the reactor an effluent gas stream including sulphur vapor, sulphur dioxide, and hydrogen sulphide, but essentially no residual ammonia.

Abstract: A catalyst for recovering elemental sulfur by the selective oxidation of hydrogen sulfide is represented by the following chemical formula: VaTibXcOf wherein, a is such a mole number that vanadium amounts to 5-40% by weight based on the total weight of the catalyst; b is such a mole number that titanium amounts to 5-40% by weight based on the total weight of the catalyst; X is an element selected from the group consisting of Fe, Mn, Co, Ni, Sb and Bi; c is such a mole number that X amounts to 15% by weight or less based on the total weight of the catalyst; and f is such a mole number that oxygen is contained to the final 100% by weight. The catalyst can recover elemental sulfur at high rates for a long period of time without being deteriorated in activity. The high catalytic activity is maintained even when excess water is present in the reaction gas.

Abstract: A selected contaminant is removed from a gas stream containing an unselected component that is also absorbed by the solvent, although to a lesser degree than the selected contaminant. In a typical application, hydrogen sulfide is removed from a natural gas stream that contains carbon dioxide as an unselected component. The process employs a solvent absorption/regeneration sequence, carried out in an absorber and regenerator, to remove the selected contaminant (hydrogen sulfide, for example) from the gas stream. The overhead gas from the regenerator has a higher concentration of the selected contaminant than the original gas stream. This contaminant rich overhead gas stream is partially employed as a recycle stream that is combined with the original gas stream, with the resulting combined gas stream being fed to the absorber.

Abstract: Elemental sulfur is recovered from the hydrogen sulfide present in natural gases and other process gases by treating the hydrogen sulfide-containing gas in a series arrangement of a liquid-phase reactor; a furnace and a sulfur dioxide absorber. The hydrogen sulfide-containing gas and a sulfur dioxide-containing gas are fed into the liquid-phase reactor where they are dissolved into a solvent, such as polyglycol monoethers, diethers of ethylene glycol, diethers of propylene glycol, etc., and react in the presence of a catalyst, such as tertiary amine, pyridine, isoquinoline, etc., to produce elemental sulfur. The feed rates of the hydrogen sulfide-containing gas and the sulfur dioxide-containing gas are selected so that there will be an excess of hydrogen sulfide in the solvent thereby ensuring that the reaction products will include, not only the elemental sulfur, but also residual, unreacted hydrogen sulfide.

Abstract: A gas stream containing at least 50% by volume of ammonia but eventually no hydrogen sulphide is burned in a reaction region which is supplied with oxygen and oxygen-enriched air. Both combustion and thermal cracking of ammonia takes place in the reaction region. The rate of supplying oxygen moleculars to the reaction region is from 75 to 98% of the stoichiometric rate required for full combustion of all combustible fluids supplied to the reaction region. Under these conditions essentially no ammonia remains in the effluent gas but formation of oxides of nitrogen can be minimised.

Abstract: A process is provided to recover residual H2S, SO2, COS and CS2 in the tail gas from a sulphur recovery process. The tail gas is oxidized and hydrolyzed at a temperature of from 180° C. to 700° C. to provide an oxidized and hydrolyzed gas stream containing substantially no COS or CS2 and having a concentration by volume of H2S and SO2 such that the H2S concentration minus twice the SO2 concentration is from 0.25% to 0.5%. Then the gas stream from the hydrolysis is passed over a Claus catalyst, for example based on alumina and/or titanium oxide, for the reaction of H2S with SO2 to form sulphur and provide a gas stream with substantially no SO2.

Abstract: The invention disclosed relates to a process for removing hydrogen sulfide from a gas stream, such as sour natural gas, with the formation of elemental sulfur as a by-product. By controlling the reaction conditions, the conversion of hydrogen sulfide is maximized, and the sulfur dioxide selectivity is controlled. Specifically, the sulfuric acid concentration and the reaction temperature may be balanced, depending on the desired product mix.

Abstract: A process and apparatus for removing hydrogen sulfide and recovering elemental sulfur from a hydrogen sulfide containing gas particularly useful for removing hydrogen sulfide (H2S) from tail gas. The process includes treating a hydrogen sulfide containing gas in a sulfur conversion unit to convert hydrogen sulfide to elemental sulfur, processing the tail gas from the sulfur-conversion unit via hydrolysis/hydrogenation to convert sulfur dioxide and other sulfur containing compounds to hydrogen sulfide, and passing the tail gas through a catalytic oxidation-reduction process to convert hydrogen sulfide gas to elemental sulfur.

Abstract: In a known process and system wherein hydrogen sulfide is removed from a gaseous stream, using a non-aqueous scrubbing liquor which can be an organic solvent for elemental sulfur such as a phenylxylyl ethane in which are dissolved sulfur and a reaction-promoting amine base such as a tertiary amine, sulfur dioxide is added to the sulfur-amine nonaqueous sorbent (or advantage is taken of SO2 which may already be present in the gas stream) to obtain better H2S removal, lower chemical degradation rates, and lower rates of formation of byproduct sulfur salts such as sulfates.

Abstract: A method, apparatus and system for treating a stream containing H2S are disclosed. A preferred method comprises mixing the stream containing H2S with a light hydrocarbon stream and an oxygen containing stream to form a feed stream; contacting the feed stream with a catalyst while simultaneously raising the temperature of the stream sufficiently to allow partial oxidation of the H2S and partial oxidation of the light hydrocarbon to produce a product stream containing elemental sulfur, H2O, CO and hydrogen, and cooling the product stream sufficiently to condense at least a portion of the elemental sulfur and produce a tail gas containing CO, H2, H2O and any residual elemental sulfur, and any incidental SO2, COS, and CS2 from the hydrocarbon stream or produced in the process. The tail gate is contacted with a hydrogenation catalyst so that CO is then reacted with water to produce CO2 and hydrogen and any elemental sulfur, SO2, COS, and CS2 in the tail gas is preferably converted into H2S.

Abstract: The emissions of hydrogen sulfide during the production of natural gas, oil or geothermal fluids from subterranean formations and the subsequent processing of these fluids is reduced by converting the hydrogen sulfide into a hydrogen halide or a halogen acid and then using the hydrogen halide or halogen acid for scale control and/or well acidizing. In a preferred embodiment, hydrogen sulfide produced with geothermal fluids is converted into hydrochloric acid, which is then used to reduce pH and control scale formation during the extraction of energy from geothermal fluids in a geothermal power plant.

Abstract: A process for catalytically oxidizing H2S contained in a gas directly to sulphur containing the following steps: combining the H2S-containing gas with a gas containing free oxygen in an amount to produce an oxygen-enriched H2S-containing gas having O2/H2S molar ratio ranging from about 0.05 to about 15; and contacting the oxygen-enriched H2S-containing gas with a catalyst for selective oxidation of H2S to sulphur, wherein the catalyst includes a catalytically active phase combined with a silicon carbide-based support and wherein the active phase of the catalyst consists of at least one oxysulphide of at least one metal selected from the group consisting of iron, copper, nickel, cobalt, chromium, molybdenum and tungsten, at a temperature above the dew point of sulphur formed during H2S oxidation.

Abstract: Sulfur vapor is formed by partial oxidation of hydrogen sulphide. A burner is operated so as to establish a flame in a furnace in or into which the burner fires. There is supplied to the flame from the first region of the mouth of the burner at least one flow of a first combustible gas comprising hydrogen sulfide. At least one second flow of a first oxidizing gas is caused to issue from the mouth of the burner and mix in the flame with the first combustible gas. There is supplied to the flame from a second region of the mouth of the burner surrounding and spaced from the said first region at least one third flow of a second combustible gas comprising hydrogen sulfide. At least one fourth flow of a second oxidizing gas is caused to issue from a region or regions of the mouth of the burner surrounded by said second region and mix in the flame with the second combustible gas. At least one fifth, outermost flow of a third oxidizing gas is caused to mix in the flame with the second combustible gas.

Abstract: A method for selectively oxidizing hydrogen sulfide to elemental sulfur is disclosed. The method is performed at a temperature ranged from 50 to 400° C. and at a pressure ranged from 0.1 to 50 atm. The elemental sulfur can be effectively recovered from a gas mixture containing hydrogen sulfide in the presence of a catalyst. The catalyst includes a vanadium-containing material and a catalytic substance selected from the group consisting of scandium (Sc), yttrium (Y), lanthanum (La), samarium (Sm) and compounds thereof. In another embodiment, this catalyst further includes an antimony-containing promoter (antimony compounds) which further exhibit a more effective catalytic performance.

Abstract: A first combustible gas stream containing hydrogen sulphide is subjected to treatment in a first Claus plant including a first thermal Claus stage. Part of the hydrogen sulphide content of a second combustible gas stream containing hydrogen sulphide is burned in at least one further thermal Claus stage. The combustion in the further thermal Clause stage is supported by oxygen-enriched air having an oxygen mole fraction of at least about 0.25 or by oxygen. Resulting sulphur dioxide in the further thermal Clause stage reacts with residual hydrogen sulphide to form sulphur vapour which is condensed out of the effluent gas from the further thermal Claus stage to form a sulphur-depleted effluent gas stream. A first control signal is generated which is a function of the flow rate of the second gas. A second control signal which is a function of the hydrogen sulphide/sulphur dioxide mole ratio in the sulphur-depleted effluent stream is also generated.

Abstract: The invention relates to a catalyst on support for the selective oxidation of sulfur-containing compounds to elemental sulfur, comprising at least one catalytically active material that is present on a support material, wherein the catalytically active material consists at least partly of a mixed oxide with an oxidic lattice, in which at least two metals in the form of ions are included.

Abstract: A method for selectively oxidizing hydrogen sulfide to elemental sulfur is disclosed. The elemental sulfur can be effectively recovered from a gas mixture containing hydrogen sulfide in the presence of a multi-component catalyst. The multi-component catalyst includes an antimony-containing substance and a vanadium-and-magnesium-containing material. The antimony containing substance may be antimonous oxide (Sb2O3) or antimony tetraoxide (&agr;-Sb2O4), and the vanadium and magnesium containing material may be magnesium pyrovanadate (Mg3V2O8) or Mg2V2O7.

Abstract: Sulphur is recovered from a first gas stream comprising hydrogen sulphide and at least 50% by volume of ammonia and from a second gas stream comprising hydrogen sulphide but essentially no ammonia, the first gas stream, the second gas stream, and combustion supporting gas comprising at least one stream of essentially pure oxygen or oxygen-enriched air are fed to a single combustion zone or a plurality of combustion zones in parallel with each other without premixing of combustible gas with oxygen or air, and creating in the or each combustion zone at least one region in which thermal cracking of ammonia takes place, and taking from the reactor an effluent gas stream including sulphur vapour, sulphur dioxide, and hydrogen sulphide, but essentially no residual ammonia.

Abstract: A regenerative process for oxidizing H2S contained in low concentration in a gas directly to sulphur including combining the H2S-containing gas with a gas containing free oxygen in an amount to form an O2/H2S-containing gas with an O2/H2S molar ratio ranging from 0.05 to 15; contacting the O2/H2S-containing gas with a catalyst for the selective oxidation of H2S to sulphur, wherein the catalyst includes a catalytically active phase containing at least one oxysulphide of at least one metal selected from the group consisting of nickel, iron, cobalt, copper, chromium, molybdenum and tungsten combined with a silicon carbide support and including a compound of at least one transition metal, at temperatures below the dew point of the sulphur formed by oxidation of H2S and depositing the sulphur on the catalyst; periodically regenerating by flushing the sulphur-laden catalyst using a non-oxidizing gas at temperatures of between 200° C. and 500° C.

Abstract: The invention provides a catalyst; a method for making the catalyst and a method for using the catalyst to promote the selective oxidation of hydrogen sulfide into elemental sulfur. The catalyst may be prepared by contacting a catalyst support, such as silica, with a solution containing ammonium metal salts, such as ammonium iron citrate and ammonium zinc citrate, and an amount of chloride (e.g., ammonium chloride) that is between about 0.1 and about 20 weight percent of the metal ions in the solution, to produce a support material impregnated with ammonium metal citrate salts and ammonium chloride. This impregnated catalyst support is then dried and calcined to produce a catalyst, such as iron and zinc oxide mixture supported on silica. It has been found that by adding chloride to the impregnated catalyst support prior to calcination and drying, that the sintering of the metal oxides can be controlled and the formation of a mixed metal oxide is promoted.