Abstract: Oxygen or oxygen-enriched air is employed to support combustion in furnaces (16) and (26) of part of the hydrogen sulphide content of a first feed gas stream. Sulphur vapour is extracted in condenser (32) from the resulting gas mixture so as to form a sulphur vapour depleted gas stream. The sulphur vapour depleted gas stream is passed into a catalytic reduction reactor (40) in which all the residual sulphur dioxide is reduced to hydrogen sulphide. This reduced gas mixture has water vapour extracted therefrom in a quench tower (52). The resulting water vapour depleted gas stream flows to a Claus plant for treatment typically together with a second feed gas steam comprising hydrogen sulphide. Employing both furnaces (16) and (26) makes it possible to obtain effective conversions to sulphur of the hydrogen sulphide in the feed gas without having the recycle any of the water vapour depleted gas.

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: Oxygen or oxygen-enriched air is employed to support combustion in furnace (16) of part of the hydrogen sulphide content of a first feed gas stream. Sulphur is extracted from the resulting gas stream in a sulphur condenser (26). Catalyst Claus reaction between hydrogen sulphide and sulphur dioxide in the resulting sulphur vapour depleted gas stream takes place in a catalytic reactor (32). Sulphur is extracted in a further sulphur condenser (34). The resulting sulphur vapour depleted gas stream is passed into a catalytic reduction reactor (40) in which all the residual sulphur dioxide and any sulphur vapour are reduced to hydrogen sulphide. The resulting reduced gas mixture has water vapour extracted there from in a quench tower (52). The resulting water vapour depleted gas stream flows to a Claus plant for further treatment typically together with a second feed gas stream.

Abstract: An activated carbon-metal oxide matrix is disclosed. The activated carbon-metal oxide matrix may by obtained by a method including the steps of: preoxidizing a carbon material, grinding the preoxidized carbon material; mixing the ground preoxidized material with a metal oxide to form a carbon mixture; extruding the carbon mixture; carbonizing and activating the extrudate. The activated carbon-metal oxide matrix may be used to remove odorous compounds, acidic gases, and volatile organic compounds from a gas.

Abstract: The invention is directed to a process for the catalytic reduction of sulphur dioxide from a gas mixture at least containing 10 vol. % of water, in which process the gas mixture is passed over a sulphur resistant hydrogenation catalyst in sulphidic form, at a space velocity of at least 2000 h−1, in the presence of a reducing component, preferably at least partly consisting of hydrogen, in a molar ratio or reducing component to sulphur dioxide of more than 10 up to 100, at a temperature of 125° C. to 300° C., followed by passing the gas mixture, after the said reduction, through a dry oxidation bed for the oxidation of sulphur compounds, more in particular hydrogen sulphide, to elemental sulphur.

Abstract: An apparatus and process for recovering elemental sulfur from a H2S-containing waste gas stream are disclosed, along with a method of making a preferred catalyst for catalyzing the process. The apparatus preferably comprises a short contact time catalytic partial oxidation reactor, a cooling zone, and a sulfur condenser. According to a preferred embodiment of the process, a mixture of H2S and O2 contacts the catalyst very briefly (i.e, less than about 200 milliseconds). Some preferred catalyst devices comprise a reduced metal such as Pt, Rh, or Pt—Rh, and a lanthanide metal oxide, or a pre-carbided form of the metal. The preferred apparatus and process are capable of operating at superatmospheric pressure and improve the efficiency of converting H2S to sulfur, which will reduce the cost and complexity of construction and operation of a sulfur recovery plant used for waste gas cleanup.

Abstract: In a process for producing elemental sulfur by combustion of hydrogen sulfide or a hydrogen-sulfide-containing gas, in particular a Claus process, the hydrogen sulfide or the hydrogen-sulfide-containing gas undergoes partial combustion by using a first device in the form of a burner to which usually air is added as an oxidizing agent and which is connected to the combustion chamber. The hydrogen sulfide or the hydrogen-sulfide-containing gas undergoes further combustion by means of a second device in form of at least one nozzle which is also connected to the combustion chamber and through which oxygen or an oxygen containing gas is fed into the combustion chamber, as a result of which the hydrogen sulfide or the hydrogen-sulfide-containing gas is subjected to afterburning and is then fed to a waste-heat boiler and thereafter to one or more reactors.

Abstract: A process is provided for producing elemental sulfur from hydrogen sulfide contained in an acid gas feed stream wherein hydrogen sulfide and sulfur dioxide are reacted in a catalytic only sulfur recovery unit comprising a single catalytic converter containing a Claus catalytic reaction zone. A sulfur dioxide-enriched gas recovered from tail gas treatment is recycled and introduced into the catalytic reaction zone as part of a feed gas mixture that also includes the acid gas feed stream. Temperatures within the catalytic reaction zone are effectively moderated by recycle of tail gas effluent to the converter so that high concentrations of hydrogen sulfide in the acid gas feed stream can be tolerated and improved process flexibility and capacity are realized. A pretreatment process including contacting the acid gas with an aqueous acid wash to reduce the concentration of unsaturated hydrocarbons in the acid gas and inhibit deactivation of the oxidation catalyst is also disclosed.

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: 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: 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 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: 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: 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: 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: 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: An apparatus and process for recovering elemental sulfur from a H2S-containing waste gas stream are disclosed, along with a method of making a preferred catalyst for catalyzing the process. The apparatus preferably comprises a short contact time catalytic partial oxidation reactor, a cooling zone, and a sulfur condenser. According to a preferred embodiment of the process, a mixture of H2S and O2 contacts the catalyst very briefly (i.e, less than about 200 milliseconds). Some preferred catalyst devices comprise a reduced metal such as Pt, Rh, or Pt—Rh, and a lanthanide metal oxide, or a pre-carbided form of the metal. The preferred apparatus and process are capable of operating at superatmospheric pressure and improve the efficiency of converting H2S to sulfur, which will reduce the cost and complexity of construction and operation of a sulfur recovery plant used for waste gas cleanup.

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: 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 for less than about 10000 microseconds while simultaneously raising the temperature of the stream sufficiently to allow oxidation of the H2S and partial oxidation of the light hydrocarbon to produce a product stream containing elemental sulfur, CO and hydrogen, and cooling the product stream sufficiently to condense at least a portion of the elemental sulfur and produce a tail gas.

Abstract: The invention is directed to a process for the selective oxidation of hydrogen sulphide to elemental sulphur, said process comprising feeding a hydrogen sulphide containing gas to a bed of a catalyst that promotes the selective oxidation of hydrogen sulphide to elemental sulphur, together with an oxygen containing gas, whereby the amount of oxygen in the gasmixture leaving the selective oxidation bed is kept substantially constant at a pre-set value using a feed forward control of the amount of oxygen containing gas to be fed to the selective oxidation.

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: 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: A process for recovery of hydrogen fluoride comprises contacting a gaseous mixture containing hydrogen fluoride and an organic compound with a solution of an alkali metal fluoride in hydrogen fluoride, separating a gas phase depleted in hydrogen fluoride and containing the organic compound from a liquid phase enriched in hydrogen fluoride, and then recovering the hydrogen fluoride from the liquid phase.

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: Part of a hydrogen sulfide containing feed gas is burnt in a furnace 6 in the presence of oxygen or oxygen-enriched air. Sulfur dioxide is formed and reacts with remaining hydrogen sulfide to form sulfur vapor which is extracted by means of a condenser 16. The resulting sulfur vapor depleted gas stream is reduced to hydrogen sulfide in a reactor 22. Water vapor is removed from the gas mixture condensation in a quench tower 32. A part of the resulting water-depleted gas stream is recycled to the furnace 6. Another part is sent for further treatment to form a purge stream.

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: 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 present invention is a process wherein a process gas comprising at least SO2 and H2S is reacted across a stage of SO2 reducing catalyst, thereby obtaining high conversion of at least the SO2 to elemental sulfur.

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.