Abstract: A method to recover sulfur comprising the steps of feeding an acid gas stream to a combustion furnace, condensing the cooled furnace stream to produce a first gas stream, feeding the first gas stream to a first adsorber comprises a molecular sieve, feeding the first hot dry gas stream to a first catalytic reactor, cooling the first catalytic outlet stream in a first condenser, feeding the second gas stream to a second adsorber, feeding the second hot dry gas stream to a second catalytic reactor, cooling the second catalytic outlet stream in a second condenser, introducing the third gas stream to a third adsorber, feeding the third hot dry gas stream to a third catalytic reactor to produce a third catalytic outlet stream, and cooling the third catalytic outlet stream in a third condenser to produce a third sulfur stream and a tail gas stream.

Abstract: The reduction of the gas stream containing sulfur dioxide to elemental sulfur is carried out by reacting a reducing gas, such as natural gas, methanol or a mixture of hydrogen and carbon monoxide, with recycled sulfur and recycled tail gas to produce a stream containing hydrogen sulfide that may be reacted with the gas stream that contains sulfur dioxide. Gas streams with a molar concentration of sulfur dioxide from 1 to 100% may be processed to achieve nearly 100% sulfur recovery efficiency.

Abstract: A compact, tiered sulfur recovery unit having a burner, a combustion chamber, a reaction chamber, a waste heat boiler and a steam drum. The waste heat boiler is mounted above the reaction chamber, and the steam drum is mounted above the waste heat boiler, resulting in a three-tiered, compact design, requiring only a single platform for space. The reaction chamber comprises a horizontal body and an upright plenum. The reaction chamber includes an inlet for receipt of acid gas (H2S). One end of the horizontal body of the reaction chamber is fluidly attached to the combustion chamber, while the other end of the horizontal body of the reaction chamber is fluidly attached to a lower end of the upright plenum of the reaction chamber. An upper end of the upright plenum of the reaction chamber is fluidly attached to the waste heat boiler. The waste heat boiler includes an outlet for the release of SO2 for downstream sulfur blowdown to produce additional elemental sulfur.

Abstract: Processes for the thermal reduction of sulfur dioxide to elemental sulfur are described and disclosed. The processes described include three general reaction sections, including the reaction furnace portion where the SO2-containing stream is combusted, the hydrogenation portion wherein the effluent from the reaction furnace is hydrogenated over an appropriate catalyst, and a Claus conversion portion, wherein residual H2S and SO2 are further reacted to produce additional elemental sulfur.

Abstract: The reduction of gas streams containing sulfur dioxide to elemental sulfur is carried out by contacting a reducing gas, such as natural gas, methanol or a mixture of hydrogen and carbon monoxide, with recycled sulfur to produce a stream containing hydrogen sulfide that may be reacted with the gas stream that contains sulfur dioxide. Gas streams with a molar concentration of sulfur dioxide from 1 to 100% may be processed to achieve nearly 100% sulfur recovery efficiency.

Abstract: Processes for the thermal reduction of sulfur dioxide to elemental sulfur are described and disclosed. The processes described include three general reaction sections, including the reaction furnace portion where the SO2-containing stream is combusted, the hydrogenation portion wherein the effluent from the reaction furnace is hydrogenated over an appropriate catalyst, and a Claus conversion portion, wherein residual H2S and SO2 are further reacted to produce additional elemental sulfur.

Abstract: A method and system for removing hydrogen sulfide from gaseous process streams, such as sour gas streams are disclosed and described. A gaseous stream containing hydrogen sulfide can be contacted with an aqueous silicon-containing composition under high shear conditions to form a sweetened gaseous product. The gaseous product has significantly reduced hydrogen sulfide content and recovered liquid and solid filtrates are generally non-toxic.

Abstract: The present invention provides a method for removing sulfur species from a gas stream without the use of a sulfur species removal process, such as an amine scrub. The sulfur species are removed by directly subjecting the gas stream to a sulfur recovery process, such as a Claus or sub-dewpoint Claus process at high pressure and moderate temperatures, wherein the sulfur recovery process comprises a catalyst which does not comprise activated carbon.

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 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: 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 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 relates to a process for the direct oxidation of sulphur compounds into elemental sulphur and/or into sulphates at a temperature below 200.degree. C., in which a supported catalyst whose catalytically active phase comprises copper is used, the copper element being present in a content of at least 2% by weight relative to the catalyst and of at least 15 by weight relative to the sum of the elements of the catalytically active phase.The use of a catalyst of this type ensures a high conversion of the H.sub.2 S while at the same time minimizing the conversion into SO.sub.2.

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 applied to a support material, this catalyst being obtainable by applying the catalytically active material to a support material which comprises at least one alkali metal promotor.

Abstract: A single-stage low temperature catalytic process for desulphurisation of a gas which contains a mixture of H.sub.2 S and SO.sub.2 which process includes feeding the gas to be treated at a temperature below the dew point of sulphur to a Claus converter having a Claus catalyst in a reaction stage in which the catalyst includes a composite catalytic mass of alumina and one or more compounds of titanium, yttrium, lanthanum or the rare-earth elements of atomic number 58 to 71, and contacting the gas with the Claus catalyst at a temperature below the dew point of sulphur, by which sulphur deposits on the Claus catalyst and the gas is desulphurised.

Abstract: The present invention discloses a method of selectively oxidizing hydrogen sulfide to elemental sulfur, in which a H.sub.2 S-containing gas mixture contacts with an oxygen-containing gas at 50.degree.-500.degree. C. in the presence of a mixed-metal catalyst. The reaction product mixture contains substantially no sulfur dioxide. The mixed-metal catalyst contains vanadium atom and molybdenum atom or magnesium atom.

Abstract: A process for reducing sulfur content in a gaseous stream with the production of elemental sulfur by first treating the gaseous steam with hydrogenation and hydrolysis to convert substantially all of the sulfur components therein to hydrogen sulfide. Then reducing the water content of the gaseous stream to optimize chemical equilibrium. Thereafter, the gaseous steam is contacted in an oxidation reactor with an acid catalyst at a temperature of about 150.degree. C. to about 350.degree. C. to convert hydrogen sulfide to elemental sulfur. The product gas leaving the oxidation reactor is cooled to separate elemental sulfur by condensation. The acid catalyst is a shape selective zeolite, a metal-exchanged or impregnated alumina, or a mixture thereof. The alumina is gamma phase alumina impregnated with from about 0.2 wt % to about 2.0 wt % metal.

Abstract: A process is provided for the improvement of the sulphur yield of an assembly which produces sulphur from H.sub.2 S and which consists of a sulphur plant (1), an oxidation and hydrolysis unit (2) and a purification unit (3). The sulphur plant in producing sulphur provides a residual gas which incorporates H.sub.2 O, COS and/or CS.sub.2 and H.sub.2 S and SO.sub.2 in a mol ratio of H.sub.2 S:SO.sub.2 >2:1. The residual gas passes into the hydrolysis unit on a H.sub.2 S oxidation and COS and CS.sub.2 hydrolysis catalyst which functions between 180.degree. C. and 700.degree. C., in the presence of air, thus producing a residual gas free of COS and CS and incorporating H.sub.2 S and SO.sub.2 in a mol ratio which is kept equal to 2:1 by regulating the air flow. The residual gas is introduced into the purification unit in which H.sub.2 S and SO.sub.2 are made to react in order to produce sulphur and to obtain a purified residual gas.

Abstract: A part of the hydrogen sulphide content of a feed gas stream comprising hydrogen sulphide is burned by a burner that fires into a furnace. The combustion is supported by a stream of oxygen or oxygen-enriched air. Resulting sulphur dioxide reacts with residual hydrogen sulphide in the furnace to form sulphur vapor. Sulphur is condensed out of the resulting gas mixture in a sulphur condenser. At least part of the sulphur-free gas mixture flows through a reactor in which its sulphur dioxide content is reduced to hydrogen sulphide. Water vapor is removed from the resulting gas stream in a water condenser. At least part of the gas stream now essentially free of water vapor is recycled to the furnace. A purge stream is taken either from immediately downstream of the sulphur condenser or from intermediate the water condenser and the furnace, or from the furnace and, if desired, subjected to further treatment to remove sulphur-containing gases therefrom.

Abstract: Provided is an improved process for removing sulfur compounds from sulfur contaminated fluid streams by contacting such fluid streams with an absorbent composition comprising zinc oxide, silica, and molybdenum disulfide. The absorbent composition comprising zinc oxide, silica, and molybdenum disulfide is a novel composition which has the desirable properties of high sulfur loading capacity and the, ability to be contacted with the hydrogen sulfide containing fluid stream for the removal of such hydrogen sulfide from said fluid stream with a minimum amount of sulfur dioxide slippage. An additional embodiment of the disclosed invention includes a method for minimizing the amount of extrusion die wear during the production of the zinc oxide based absorbent compositions. Extrusion die wear is reduced by adding a quantity of molybdenum disulfide to the zinc oxide absorbent in an amount which provides desirable lubricating properties such that extrusion die wear is reduced during the manufacture of the composition.

Abstract: Apparatus and process for the catalytic gaseous phase reaction of a feed gas mixture. The apparatus includes a reactor having two ends which alternately serve as an inlet for the feed gas mixture and as an outlet for reacted gas and two stationary heat exchange/reaction zones connected by a center zone. Each of the heat exchange/reaction zones contains a layer of catalyst and the center zone contains a feed gas mixture inlet. A first distribution/collection zone is between one of the heat exchange/reaction zones and one of the ends of the reactor and a second distribution/collection zone is between the other heat exchange/reaction zone and the other end of the reactor. In the process, the heat exchange/reaction zones are alternately heated and cooled by periodically reversing the direction of flow of gas through the reactor.

Abstract: A method for producing elemental sulfur and reduced/oxidized sulfur compounds from sulfur containing gases. The method comprises mixing a primary gas stream of sulfur-containing gases with a secondary gas stream to produce a combined gas stream having a preselected stoichiometry and contacting the combined gas stream with a sorbent/catalyst. The sorbent/catalyst is selected form the group consisting of silica, alumina, and other Claus-type catalysts, sodium/alumina, zinc ferrite, zinc titanate, and other mixed metal oxides, and mixtures thereof.

Abstract: The gas to be treated contains H.sub.2 S and carbon compounds first enters the combustion chamber of a Claus process plant and a gas mixture which contains 1 to 3 moles H.sub.2 S per mole of SO.sub.2 is withdrawn from that combustion chamber. The gas mixture is reacted in part to form elemental sulfur in at least one catalytic Claus process stage at temperatures above the dew-point temperature of the sulfur. The elemental sulfur is condensed in and removed from a sulfur cooler. An exhaust gas which contains 0.5 to 5% by volume H.sub.2 S and also contains COS, CS.sub.2 and H.sub.2 O is withdrawn from the last sulfur cooler of the Claus process plant. Oxygen is admixed with that exhaust gas, which is heated to a temperature of at least 200.degree. C. and is contacted with a catalyst, which comprises at least 80% by weight TiO.sub.2. The resulting elemental sulfur is condensed and withdrawn. The gas is subsequently contacted at temperatures of 120.degree. to 160.degree. C.

Abstract: To a gas which contains H.sub.2 S and water vapor and which is to be desulfurized oxygen is added at such a rate that the gas contains 1 to 20 moles O.sub.2 per mole of H.sub.2 S. At a temperature in the range of 50.degree. to 180.degree. C. the gas is contacted with activated carbon, which is thus laden with elemental sulfur and with at least 3% by weight sulfuric acid. In a suitable processing, the gas which is to be desulfurized and contains at least 1000 ppm H.sub.2 S+SO.sub.2 is initially passed at a temperature from 100.degree. to 180.degree. C. through a catalytic prepurifier, in which elemental sulfur is adsorbed on a high-metal-oxide catalyst, oxygen is admixed to the gas coming from the prepurifier and the gas at a temperature of 50.degree. to 180.degree. is contacted with the activated carbon for a final desulfurization.

Abstract: A process is provided for improving the sulphur yield of a sulphur production unit using an acid gas containing H.sub.2 S and wherein said unit is comprised of a sulphur plant with a downstream purification unit. The H.sub.2 S resulting from hydrolysis of COS and CS.sub.2 is almost entirely recovered in the form of sulphur in the purification unit resulting in an improved sulphur output of the overall installation.

Abstract: The process of this invention will remove acid rain precursors, sulfur oxides (SOX) and nitrogen oxides (NOX) by catalytically reducing the NOX to water and elemental nitrogen and the SOX to either H.sub.2 S or elemental sulfur as desired. The process employs specific catalysts in the heteropoly acid or salt group and the spinel or inverse spinel group. The process conditions achieve an oxygen-free environment and reduction is effected with stoichiometric to 100% excess above stoichiometric H.sub.2 or H.sub.2 and CO as reducing gas. Temperatures can be 200.degree. to 900.degree. C. with the lower temperature range being favored space velocity can be 2000 to 20,000 and still achieve 95+% abatement. The only product of the reaction which must be disposed of is saleable elemental sulfur.

Abstract: A continuous process for removing sulfur oxide and nitrogen oxide contaminants from the flue gas generated by industrial power plants and boiler system burning sulfur containing fossil fuels. The sulfur oxide and nitrogen oxide contaminants removed from the flue gas are converted, respectively, into elemental liquid sulfur product, and into nitrogen gas, ammonia gas and mixtures thereof which are released to the atmosphere thus reducing industrial air pollution.

Abstract: Multilobar shaped catalyst particulates, e.g., tri- or quadrilobar particulates, well adapted for the catalytic conversion of gases containing compounds of sulfur, e.g. SO.sub.2, H.sub.2 S, COS and/or CS.sub.2, by the Claus reaction and/or by hydrolysis, are comprised of a catalytically effective amount of values catalytically active in the Claus reaction and/or reactions entailing hydrolysis of organosulfur compounds.

Abstract: The desulfurization of industrial gases by the catalytic conversion of contaminating sulfur values therein, comprising, e.g., either Claus process or hydrolysis of organosulfur compounds, is carried out in the presence of an effective amount of a cerium oxide-based catalyst.

Abstract: The invention relates to a catalyst for the selective oxidation of sulfur-containing compounds, in particular hydrogen sulfide, to form elemental sulfur, comprising a carrier of which the surface exposed to the gaseous phase does not exhibit alkaline properties under the reaction conditions, and a catalytically active material applied thereto or formed thereon. According to the invention the catalyst is characterized in that the specific surface area of the catalyst is less than 20 m.sup.2 /g catalyst, with less than 10% of the total pore volume having a pore radius between 5 and 500 .ANG.. The invention also relates to a process for preparing the catalyst, and to processes using it.

Abstract: A catalytic process for the production of sulphur from an acid gas containing H.sub.2 S, in which a part of H.sub.2 S is catalytically oxidized in order to form an effluent containing H.sub.2 S and SO.sub.2 in a molar ratio of 2:1 and a given quantity of sulphur, then said effluent is contacted with a CLAUS catalyst to form a further quantity of sulphur.The catalytic oxidation of H.sub.2 S is carried out in the presence of an oxidation catalyst consisting of agglomerates comprising an active alumina thermally stabilized by at least one oxide from the group consisting of SiO.sub.2, ZrO.sub.2, the rare-earth metal oxides and the alakline-earth metal oxides to which are associated one or more compounds of metals such as iron that promote the oxidation of H.sub.2 S.

Abstract: The removal of sulfur oxide (particularly sulfur dioxide) from a fluid stream, such as the tail gas from a sulfur process, is accomplished by contacting such fluid stream with a catalyst composition comprising zinc titanate and a promoter in the presence of a hydrogen donor.

Abstract: An improved Claus catalyst comprising activated alumina in which sodium oxide concentration is controlled to achieve increased sulfur conversion. Sodium oxide is present in an amount greater than 1.0 wt % (1100.degree. C. calcined basis), the remainder being activated alumina. Specific surface area is greater than 100 m.sup.2 /g (BET). The catalyst preferably has a surface area greater than 300 m.sup.2 /g (BET) and an LOI (hydroxyl content as determined by heating from 400.degree. to 1100.degree. C.) between 2.0 and 6.0 wt %.

Abstract: A catalytic process for the production of sulphur from an acid gas containing H.sub.2 S, in which a part of H.sub.2 S is catalytically oxidized in order to form an effluent containing H.sub.2 S and SO.sub.2 in a molar ratio of 2:1 and a given quantity of sulphur, then said effluent is contacted with a CLAUS catalyst to form a further quantity of sulphur.The catalytic oxidation of H.sub.2 S is carried out in the presence of an oxidation catalyst consisting of agglomerates comprising an active alumina thermally stabilized by at least one oxide from the group consisting of SiO.sub.2, ZrO.sub.2, the rare-earth metal oxides and the alkaline-earth metal oxides to which are associated one or more compounds of metals such as iron that promote the oxidation of H.sub.2 S.

Abstract: An improved Claus catalyst comprising activated alumina in which sodium oxide concentration is controlled to achieve increased sulfur conversion. Sodium oxide is present in an amount greater than 0.50 wt % (1100.degree. C. calcined basis), the remainder being activated alumina. Specific surface area is greater than 100 m.sup.2 /g (BET). In a preferred embodiment, sodium oxide content is controlled in the range 1.0 to 2.5 wt %. The catalyst preferably has a surface area greater than 300 m.sup.2 /g (BET) and an LOI (hydroxyl content as determined by heating from 400.degree. to 1100.degree. C.) between 2.0 and 6.0 wt %.

Abstract: Sulfur species are removed from a Claus plant tail gas stream by contacting with zinc oxide in the presence of sufficient reducing equivalents for conversion of sulfur compounds to hydrogen sulfide. In another aspect, sulfur compounds are converted to hydrogen sulfide prior to contacting with zinc oxide.

Abstract: Ammonia and hydrogen sulfide are washed out of the coke oven gas and stripped from the wash liquor in the form of gases and fumes or vapors. The ammonia is decomposed in a nickel catalyzer and a small part of the decomposition gases is supplied directly to a combustion furnace, while the larger part of the combustion gases is first cooled and freed from condensate, and only then supplied to the combustion furnace. In the combustion furnace, the proportion of H.sub.2 S/SO.sub.2 needed for the Claus process is adjusted by a partial combustion of the decomposition gases. The gases from the combustion furnace are then processed in the Claus plant to sulfur.

Abstract: An improvement in the Claus Process for producing sulfur by reaction of hydrogen sulfide with sulfur dioxide at elevated temperature in the presence of a porous catalyst is described. The improvement lies in employing a porous catalyst, preferably alumina, having a large surface area at least 40% of which is provided by pores having diameters over the range 40 A.degree. to 150 A.degree. or having at least 20% of its surface area provided by pores having diameters over the range 80 A.degree. to 150 A.degree..

Abstract: A straight-through three reactor system and process produces acceptable levels of sulfur recovery from acid gas at a cost significantly less than that required for a standard modified four reactor Claus system. The system includes two conventional Claus reactors and one cold bed adsorption (CBA) reactor in series. Four condensers are provided, one disposed before each of the catalytic reactors, and one disposed after the CBA reactor. The system is designed to operate either in a recovery mode or in a regeneration mode. In the recovery mode, the reactors are in series and the last reactor is operated below dew point of sulfur (CBA reactor). In regeneration mode, effluent from the third condenser is heated in a first heat exchanger where effluent from the first catalytic reactor is used as the heat source. Sulfur is vaporized in the CBA reactor and is recovered in the fourth condenser. Effluent from the fourth condenser is then passed to an incinerator.

Abstract: A system and process produce high actual levels of sulfur recovery from acid gas. The system includes two conventional Claus reactors and two cold bed adsorption (CBA) reactors. Four condensers are provided, one disposed before each of the catalytic reactors, and one disposed after the CBA reactor. The system includes a gas clean-up treatment zone for hydrogenation, drying and oxidation of gas to provide stoichiometric ratio of H.sub.2 S and SO.sub.2. The gas is passed through the clean-up treatment zone prior to being fed to the first of the CBA reactors. The system is designed to operate either in a recovery mode or in a regeneration mode. In the recovery mode, the reactors are in series and the CBA reactors are operated below dew point of sulfur. In regeneration mode, effluent from the clean-up treatment zone is heated in a heat exchanger using effluent from the first catalytic reactor as the heat source.

Abstract: H.sub.2 S-containing gases are desulfurized by direct catalytic oxidation of the H.sub.2 S to elementary sulfur by means of oxygen-containing gases in a tube reactor, with indirect removal of the heat of reaction by means of a coolant and with condensation of the sulfur formed, wherein either the catalyst is present in the jacket space around the tubes and the coolant is present in the tubes of the reactor or the coolant is present in the jacket space around the tubes and the catalyst is present in the tubes of the reactor, and the catalyst fills the tubes of the tube reactor or the jacket space around the tubes over the entire cross-section of the tubes or the jacket space respectively, the exit temperature of the gaseous reaction mixture leaving the tube reactor is kept at 180.degree.-400.degree. C. and the sulfur formed in the tube reactor is separated out of the reaction mixture, obtained in the reactor, in a condensation stage downstream of the reactor.

Abstract: There is disclosed a process for the combustion of H.sub.2 S containing gases with air and/or oxygen into elementary sulfur and separation of the sulfur from the reaction gas, in a load range from between 100 and 5%. The process takes place in a combustion zone equipped with burners, an adjoining reaction zone and several cooling zones, in which--possibly after previous reheating and further catalytic transformation into sulfur--the sulfur formed condenses and is then separated. The H.sub.2 S containing gases are supplied to the combustion zone by one or several main burners in the high load range and by a by-pass burner in a low load range. In the low load range, a heating gas is also burned by a separate burner and the cooling surfaces in the cooling zones which are coated by the reaction gas are reduced.

Abstract: A straight-through four reactor system and process is disclosed for obtaining high levels of sulfur recovery from acid gas at a cost equal to or less than that required for a standard modified four reactor Claus system. Two conventional Claus reactors and two cold bed adsorption (CBA) reactors are in series. Four condensers are provided, one disposed before each of the Claus and CBA catalytic reactors. A first heater and a first bypass line is disposed between the second condenser and the second catalytic reactor (second Claus reactor) and a second heater and a second bypass line is disposed between the third condenser and the third catalytic reactor (first CBA reactor). The system is designed to operate either with both CBA reactors in a recovery mode or with one CBA reactor in a regeneration mode and the other CBA reactor in a recovery mode. When both reactors are operating in the recovery mode, the system is similar to the standard modified Claus system.

Abstract: A three catalytic reactor system and process is disclosed for obtaining acceptable levels of sulfur recovery from acid gas at a cost significantly less than that required for a standard modified four reactor cold bed adsorption (CBA) system. The system and process utilize two conventional Claus reactors and one cold bed adsorption (CBA) reactor in series. Four condensers are provided, one disposed before each of the catalytic reactors and one on a process line connecting the third catalytic (CBA) reactor to the first catalytic reactor. The system is designed to operate either in a normal adsorption mode or in a regeneration mode. In the normal adsorption mode, the second Claus reactor is operated at a closer sulfur dewpoint approach then the second Claus reactor in the standard CBA system. In the regeneration mode, gas downstream of the thermal reactor is directed first to the second Claus reactor and then, after removal of sulfur and reheating, to the CBA reactor.

Abstract: A three catalytic reactor system and process is disclosed for obtaining acceptable levels of sulfur recovery from acid gas at a cost significantly less than that required for a standard four reactor cold bed adsorption (CBA) system. The system and process of the present invention utilizes two conventional Claus reactors and one cold bed adsorption (CBA) reactor in series. Four condensers are provided, one disposed before each of the catalytic reactors, and one on a process line connecting the third catalytic (CBA) reactor to the first catalytic (Claus) reactor. The system is designed to operate either in an adsorption mode or in a regeneration mode. In the adsorption mode, the system is similar to a standard CBA system except that the present invention incorporates only one CBA reactor while a standard CBA system incorporates two CBA reactors. In the regeneration mode, however, the CBA reactor of the present invention is operated in the same manner as the first Claus reactor in adsorption mode.

Abstract: Poisoned catalyst is regenerated by first subjecting it to an oxidative burn-off and then soaking it in a base, preferably NaOH. The dried product is comparable in Claus activity to fresh catalyst.

Abstract: Claus process sulfur recovery can be improved by performing a Claus conversion under low temperature and low water concentration conditions. The process treats a feed stream containing sulfur compounds by conversion of all sulfur components to hydrogen sulfide, water removal to low water concentrations, creation of a Claus reaction mixture, and then low temperature catalytic conversion to sulfur and water.

Abstract: Claus process sulfur recovery can be improved by performing a Claus conversion under low temperature and low water concentration conditions. The process treats a feed stream containing sulfur compounds by converting all sulfur compounds in the stream to a single sulfur species, reducing water content to low water concentrations, creation of a Claus reaction mixture, and then low temperature catalytic conversion to sulfur and water.

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.