Abstract: The NH.sub.3 content is regulated in methanol used in a process for scrubbing out sour gases from gaseous mixtures and/or for preventing ice formation prior to the scrubbing step. The methanol is freed, after the scrubbing step, respectively of absorbed gaseous components and/or water, and reused in the cycle as scrubbing liquid and/or for preventing ice formation. A strong acid is added to the methanol from water-soluble ammonium salts. Thereby, dissolved salts are formed which are removed together with water. Deleterious trace acids are also removed by an analogous treatment with a basic compound. The acid/base treatments are conducted in succession.

Abstract: A Stretford process for removing hydrogen sulfide collects a horizontal pool of liquid downstream of the primary gas/liquid contactor and accelerates a multiphase flow along the surface of that pool and along a serpentine path. Additional gas-liquid contact is effected by the interaction of multiphase flow and structural components establishing the pool and causing the acceleration.

Abstract: A process is disclosed for the elimination of waste water falling out with the desulfurization of coking oven gas by means of an organic oxygen carrier--containing washing solution with simultaneous recovery of elemental sulfur. The waste water is decomposed in a combustion chamber in a reducing atmosphere at temperatures between about 1000.degree. and 1100.degree. C. under such conditions that the mole ratio of H.sub.2 S:SO.sub.2 in the exhaust gas of the combustion chamber amounts to at least 2:1. Sulfur falling out is separated and the sensible heat of the exhaust gas is utilized for steam generation. The cooled and desulfurized exhaust gas is added to the coking oven gas before the pre-cooling. Sulfur falling out from the washing solution in the oxidizer is separated out and lead into the combustion chamber together with the part of the washing solution discharged as waste water from the washing solution circulation.

Abstract: A method is provided for removing elemental sulfur particles from a hydrogen sulfide removal process which employs a regenerable, aqueous washing solution capable of absorbing hydrogen sulfide from an industrial gas stream and converting that hydrogen sulfide to elemental sulfur. The washing solution of such a process is contacted with bubbles of an oxygen-containing gas while in the presence of controlled concentrations of a selected hydrocarbon and a selected surfactant.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a strongly basic tertiary amino compound having a pK.sub.a at 20.degree. C. greater than 8.6 and a boiling point at 760 mm greater than 180.degree. C. whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: In a process of regenerating laden absorbent solutions used to desulfurize gases which contain H.sub.2 S and CO.sub.2 and possibly COS, which solutions contain at least one highly volatile secondary amine in an organic solvent, the laden absorbent solution is flashed and stripped with its own vapor. The overhead vapors from the regenerator, which consists of an indirectly heated plate column, are cooled to approximately ambient temperature. The resulting condensate is separated and fed to the top of the regenerator. The cooled gas is withdrawn. A partial stream of the vapor is withdrawn from the regenerator 1 to 10 plates below the outlet for the overhead vapors and the inlet for the condensate and is cooled to ambient temperature. The resulting condensate is fed to the regenerator 1 to 10 plates above the inlet for the absorbent solution.

Abstract: The invention relates to a method for purifying a gas mixture containing at least one undesirable gas compound utilizing certain sulfonamide or sulfamide solvents.

Abstract: Hydrogen sulfide is removed from a gas stream by injecting an alkaline solution into the gas stream. The velocity of the gas stream is such that it has a Reynolds number of at least 50,000 and the Weber number for the injected alkaline solution is at least about 16. Alkali metal hydroxides and polyvalent metal chelates are useful alkaline solutions.

Abstract: A method is provided for reconditioning a hydrogen sulfide removal system, such as a Stretford process system in which elemental sulfur is formed, after the system has become contaminated with sulfur-feeding bacteria to an extent that operation thereof is substantially impaired. The method includes adding a bactericide to the washing solution employed in the system to destroy the bacteria and adding a surfactant to the solution to remove dead bacteria from the surfaces of particulate sulfur formed in the system so that the particles can agglomerate in the intended manner to enable sulfur removal from the solution.

Abstract: For preventing the fouling and/or plugging of apparatus with metallic sulfides in the processing and purification of synthesis gases contaminated with metal carbonyls, wherein the synthesis gases are scrubbed with a physical solvent, which solvent is regenerated and reused, an organic phosphite, e.g., trimethyl phosphite, and/or an organic phosphine, e.g., triethyl phosphine or triphenyl phosphine, is added as a complexing agent to the scrubbing media, preferably in between the scrubbing and absorption regenerating steps.

Abstract: A process for removal of H.sub.2 S from gaseous streams is described, the process being characterized by division of the gaseous stream into major and minor portions, oxidation of the H.sub.2 S in the major portion with an oxidizing reactant solution comprising a polyvalent metal chelate or chelates of nitrilotriacetic acid, and utilization of the minor portion as a source of hydrogen ions to assist precipitation of ferrous oxalate from a bleed stream of the oxidizing reactant solution.

Abstract: A process for the removal of oxalate ion from solutions containing polyvalent metal chelates of nitrilotriacetic and the decomposition products thereof is described, the process being characterized by the addition to such solutions of sufficient composition capable of providing hydrogen ion to precipitate ferrous oxalate, but not remove the bulk of the polyvalent metal chelate or chelates of nitrilotriacetic acid.

Abstract: A process is disclosed for treating carbon dioxide-containing gas streams, such as a natural gas, to selectively remove hydrogen sulfide. The process employs an absorption-stripping sequence in which hydrogen sulfide and carbon dioxide are removed from the feed gas. The net overhead vapor of the stripping column is compressed and dried and passed into a fractionation column. Relatively high purity hydrogen sulfide is withdrawn from the bottom of the fractionation column, and the net overhead vapor of the fractionation column is recycled back to the absorption zone.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a nitrogen heterocyclic tertiary aminoalkanol or aminoetheralkanol whereby H.sub.2 S is selectively absorbed from the mixture.

Abstract: A desulfurization process for hydrogen sulfide-containing gases, which comprises contacting an alkaline aqueous medium containing a naphthoquinone sulfonate, a water-soluble compound of at least one polyvalent metal selected from the group consisting of iron, manganese, vanadium and copper, and a water-soluble high molecular compound having weight-average molecular weight of from 300 to 50,000 with a hydrogen sulfide-containing gas thereby causing the hydrogen sulfide in said gas to be absorbed by said aqueous medium and subsequently contacting said aqueous medium now containing the absorbed hydrogen sulfide with a molecular oxygen-containing gas thereby separating elementary sulfur from said hydrogen sulfide.

Abstract: In the removal of sour gases, H.sub.2 S in particular, from CO-containing gaseous mixtures containing heavy metal carbonyls by scrubbing under pressure at temperatures of below 0.degree. C. with a scrubbing medium, the scrubbing medium is regenerated by inter alia, being heated by means of heat exchangers, and such exchangers are normally fouled by precipitates of metal sulfides which owe their presence to the decomposition of the metal carbonyls to form reactive heavy metal which combines with sulfide ion. To avoid fouling of the heat exchangers, the CO partial pressure is increased during the heating of the loaded scrubbing medium, to above the partial pressure of the CO in equilibrium with the carbonyls in the scrubbing medium thereby preventing the decomposition of the carbonyls.

Abstract: For avoiding equipment fouling from metal sulfide deposition in the processing of cracked gases containing H.sub.2 S and CO, the reactive metal species capable of carbonyl formation are prevented from contacting equipment parts operating within a temperature range favoring the formation of metal carbonyls, e.g., 30.degree.-250.degree. C. To accomplish this, the cracked gas is subjected to solids separation to remove dust particles containing the reactive metal species, or the cracked gas is oxidized to inactivate the metal species. Cooling water is also subjected to a preceding step of removing the reactive metal species.

Abstract: An integrated system for the derivation of useful energy from impure steam and/or for use in connection therewith, said steam containing both hydrogen sulfide and an alkaline acting component, such as ammonia, while producing liquid-phase and gaseous-phase effluents from condensation of the impure steam and substantially reducing the emission of sulfur-containing compounds to the environment. Treatment of such effluents to selectively react or bind alkaline acting components in the liquid-phase results in an augmented concentration of hydrogen sulfide in the gaseous-phase and its depletion in the liquid-phase. The gaseous-phase comprising noncondensable gas contaminants and uncondensed water vapor is separated from the liquid-phase steam condensate and treated to remove hydrogen sulfide to produce an environmentally acceptable vent gas which the in part is employed in said treatment of the liquid-phase effluent.

Abstract: A cyclic process for the removal of hydrogen sulfide, and carbon dioxide, from a variety of gas streams is disclosed. The gas stream containing the sour gas(es) is contacted with an aqueous solution of a specific reactant ligand or chelate, or mixtures thereof, optionally in an absorbent, containing specific stabilizers for improvement of chelate life. The hydrogen sulfide is converted to sulfur, CO.sub.2 may be absorbed to produce a purified gas stream, and the reactant chelate is reduced. The process includes sulfur removal and regeneration of the reactant chelate.

Abstract: A process for removing hydrogen sulfide from sour gas streams is disclosed which is carried out in processing equipment which includes steel components resulting in iron from the steel slowly dissolving in the alkaline H.sub.2 S absorption medium. The solubilized iron tends to react with the hydrogen sulfide to form iron sulfide which further oxidizes to produce sodium thiosulfate. The preferred absorption medium includes a metal vanadate and boron complex, a quinone type reoxidation catalyst and a metal ferri or ferrocyanide decahydrate compound capable of reacting with the solubilized iron in the alkaline absorption medium to form a precipitate which is unreactive with the dissolved hydrogen sulfide.

Abstract: An aqueous oxidation-reduction composition and method for removing hydrogen sulfide gas from a fluid stream by liquid phase oxidation of the hydrogen sulfide to elemental sulfur with a chelated polyvalent metal catalyst, such as iron, wherein the composition is stabilized against rapid loss of chelated polyvalent catalyst caused by contamination of the aqueous composition with micro-organisms, such as bacteria. The aqueous composition is stabilized by incorporating in the aqueous composition and adding throughout the normal usage thereof a broad spectrum biocide in an amount which acts as a bacteriostat to prevent rapid growth of bacteria in the aqueous composition and when the bacteria concentration rises above about 1.times.10.sup.6 colonies per ml.

Abstract: Fluid streams containing hydrogen sulfide from a steam turbine or from a sour gas stream are contacted with an aqueous solution of a polyvalent metal chelate and an oxidizing agent whereby the hydrogen sulfide is converted to free sulfur and then to soluble sulfur compounds. The metal chelate is reduced to a lower oxidation state metal chelate and reduced metal chelate is subsequently oxidized with air back to the higher oxidation state and reused.

Abstract: A method of removing hydrogen sulfide contaminants from a gas stream. The gas stream is contacted with dimethyl sulfoxide promoted with the salt of an organic acid, reducing H.sub.2 S to sulfur.

Abstract: A corrosion inhibited composition containing a gas conditioning solution such as an alkanol amine with water or with organic solvents and with small amounts of soluble thiocyanate compounds, soluble trivalent bismuth compounds with or without soluble divalent nickel or cobalt compounds. The compositions are useful to separate acid gases such as carbon dioxide from hydrocarbon feed streams in gas conditioning apparatus with minimum amounts of corrosion of the ferrous surfaces.

Abstract: A process for the recovery of nitrilotriacetic acid values from solutions containing polyvalent metal complexes of nitrilotriacetic and the decomposition products thereof is described, the process being characterized by the addition to such solutions of sufficient strong acid to dissociate the complex under conditions to precipitate the nitrilotriacetic acid.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is described, the process being characterized by the utilization of washing solutions containing oxidizing polyvalent metal chelates of specified aminocarboxylic acids, and by the electrolytic regeneration of spent solutions. Use of an optional CO.sub.2 -selective absorbent in the washing solution is also disclosed.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is disclosed, the process being characterized by the use of a washing or contacting solution containing oxidizing polyvalent metal chelates of specified aminocarboxylic acids, the electrolytic regeneration of spent solution, and the co-production of hydrogen. Provision is also made for selective absorption of CO.sub.2.

Abstract: Corrosion inhibiting compositions for use in aqueous absorbent gas-liquid contacting processes for recovering carbon dioxide (CO.sub.2) from industrial gas and oil combustion and partial combustion process flue gases, particularly employing copper carbonate, in combination with one or more of dihydroxyethylglycine, alkali metal permangenate, alkali metal thiocyanate, nickel or bismuth oxides with or without an alkali metal cartonate. The inhibitors are effective in reducing corrosion of metals in contact with the aqueous absorbent in the absorbent regeneration section of the plant as well as reduce the thermal degradation of the absorbent when high oxygen content combustion gases are treated to recover the CO.sub.2.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is disclosed, the process being characterized by the use of a washing or contacting solution containing oxidizing polyvalent metal chelates of nitrilotriacetic acid, the electrolytic regeneration of spent solution, and the co-production of hydrogen.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is disclosed, the process being characterized by the utilization of washing solutions containing oxidizing metal chelates of nitrilotriacetic acid, and by the electrolytic regeneration of the spent solutions.

Abstract: Methods for removing acidic gases from gaseous mixtures, such as hydrocarbon containing gaseous mixtures, are disclosed. The method includes washing the gaseous mixtures with a methanol wash stream containing more than about 0.5 weight percent ammonia therein, so as to remove at least a portion of the acidic gases from the gaseous mixtures and to produce a laden methanol stream containing said acidic gases therein, regenerating said laden methanol stream by removing a portion of said acidic gases therefrom, so as to regenerate said wash stream, and recycling the regenerated wash stream.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is described, the process being characterized by the utilization of washing solutions containing oxidizing polyvalent metal chelates of specified amino-carboxylic acids, and by the regeneration of the spent solutions in a fuel cell mode.

Abstract: A process for the removal of H.sub.2 S from sour gas streams is described, the process being characterized by the utilization of washing solutions containing oxidizing polyvalent metal chelates of nitrilotriacetic acid, and by the regeneration of the spent solutions in a fuel cell mode.

Abstract: In the simultaneous scrubbing and oxidation of H.sub.2 S with a vanadate-containing aqueous alkaline scrubbing agent, so as to prevent precipitation of vanadium values, the concentration of CO.sub.3 -- ions in the scrubbing agent is adjusted, preferably to a minimum content of CO.sub.3.sup.-- ions of 12.5 g/l of scrubbing agent. The scrubbing agent is regenerated conventionally by treatment with an oxygen-containing gas in an oxidizer.

Abstract: The removal of CO.sub.2 and mixtures thereof with H.sub.2 S from gaseous mixture containing same, is carried out by using an absorbing solution which comprises a first activating substance chosen from aminoacids and primary and secondary ethanolamines, which effects the initial absorption of CO.sub.2 with formation of a carbamate, a second activating substance chosen from As.sub.2 O.sub.3 and its derivatives, secondary ethanolamines and ammonia, which promotes the hydrolysis and decomposition of the carbamate as the latter forms, and a third substance of a basic nature, which effects the quantitative absorption of CO.sub.2 or CO.sub.2 +H.sub.2 S.

Abstract: In the scrubbing and simultaneous oxidation of hydrogen sulfide with an aqueous alkaline scrubbing solution containing five-valent vanadium as the oxidizing agent, the sulfide being converted into higher oxidation states with simultaneous reduction of the five-valent vanadium to four-valent vanadium, the scrubbing solution subsequently being regenerated for reuse in a downstream oxidizer by treatment with an oxygen-containing gas for the reoxidation of the four-valent vanadium, to avoid losses of vanadium when the pH in the scrubbing solution is below 9.5, using the vanadium in a ration which exceeds the stoichiometric ratio for the oxidation of the hydrogen sulfide.

Abstract: In a process wherein hydrogen sulphide is removed from a gaseous mixture by scrubbing with an aqueous alkaline scrubbing solution containing an oxidizing agent, which process ordinarily results in a buildup of S.sub.2 O.sub.3.sup.-- ion, in order to reduce the rate of formation of S.sub.2 O.sub.3.sup.-- ions, the pH of the alkaline scrubbing solution is maintained at below 9 preferably at 8.0-8.5, with CO.sub.2 being preferably employed as the pH adjusting reagent.

Abstract: A hydrogen sulfide removal and conversion method in which a hydrogen sulfide-containing gas stream is contacted with a regenerable washing solution having a pH between about 5 and about 10 and containing solubilized vanadium, thiocyanate ions, a carboxylate complexing agent, one or more water-soluble quinones and one or more water-soluble nonquinone aromatic compounds capable of solubilizing tetravalent vanadium. The absorbed hydrogen sulfide is converted to elemental sulfur which, after oxidative regeneration of the washing solution, is separated from the regenerated solution.

Abstract: An improved process for the removal of H.sub.2 S from sour gas streams in which the H.sub.2 S is converted to sulfur by a polyvalent metal chelate solution is disclosed, the process being characterized by the washing of the product sulfur with an aqueous wash solution, and recovery of the acid precursor of the chelating agent from the washing solution.

Abstract: In a system for the separation of sour gases especially hydrogen sulfide and carbon dioxide from a raw gaseous mixture e.g., hydrogen-containing in order to form a purified gaseous mixture, comprising scrubbing the gaseous mixture in a first scrubbing stage with a physical scrubbing liquid e.g., methanol having a higher absorbability for hydrogen sulfide than for carbon dioxide, withdrawing from the scrubbing stage a first stream of scrubbing liquid loaded with hydrogen sulfide and carbon dioxide, and regenerating the loaded scrubbing liquid to form (a) a gaseous phase containing hydrogen sulfide, and (b) regenerated scrubbing liquid, the improvement of scrubbing said gaseous phase containing hydrogen sulfide in a second scrubbing stage with a stream of scrubbing liquid capable of absorbing additional H.sub.2 S, e.g., a CO.sub.2 -depleted stream from an H.sub.

Abstract: In a process for the separation of at least carbon dioxide and hydrogen sulfide from a raw gaseous mixture to form a purified gaseous mixture comprising passing said gas through a sour gas removal system including the steps of scrubbing said gaseous mixture with a liquid scrubbing agent having a higher affinity for hydrogen sulfide than for carbon dioxide, removing from said system an off-gas enriched in hydrogen sulfide, and passing said off-gas to a sulfur recovery system comprising the conversion of sulfur values to elemental sulfur and the recovery of a tail gas containing hydrogen sulfide and sulfur dioxide,the improvement which comprises hydrogenating said tail gas to convert sulfur dioxide to hydrogen sulfide and recycling resultant hydrogenated tail gas to said sour gas removal system, whereby essentially no hydrogen sulfide or sulfur dioxide is discharged into the environment.

Abstract: A cyclic process for the removal of hydrogen sulfide, and carbon dioxide, from a variety of gas streams is disclosed. The gas stream containing the sour gas(es) is contacted with an aqueous solution of a specific reactant ligand or chelate, or mixtures thereof, optionally in an absorbent, containing a stabilizer selected from specified bisulfites for improvement of chelate life. The hydrogen sulfide is converted to sulfur, CO.sub.2 may be absorbed to produce a purified gas stream, and the reactant chelate is reduced. The process includes sulfur removal and regeneration of the reactant chelate.

Abstract: A cyclic process for the removal of H.sub.2 S from gas stream is disclosed, the process being characterized by reaction of the H.sub.2 S to sulfur employing specific aqueous solution reactants, and by recovery of the sulfur employing specific extractants.

Abstract: In a process wherein hydrogen sulfide is converted to elemental sulfur in the presence of oxygen, an improvement is made by employing an alcoholic solution of an alkali metal hydroxide, free of iron-group salts or other heterogeneous catalysts. High yields of pure sulfur are obtained from such reactions begun at room temperature, without a requirement for heterogeneous catalysts or troublesome intermediates such as sulfur dioxide.

Abstract: An integrated process to selectively remove and separate H.sub.2 S, CO.sub.2 and COS from a feed gas stream is disclosed. The process involves three separate absorption/regeneration steps. In the first step the feed gas is contacted with an absorbent solution to selectivity remove CO.sub.2 and H.sub.2 S but not COS. The COS-rich stream is then contacted in another stage to selectively remove the COS. After stripping the CO.sub.2 and H.sub.2 S gaseous stream from the first stage, the acid gas stream is contacted with a separate absorption stream to selectively remove the H.sub.2 S. As a result four separate gaseous streams are produced--a purified acid gas-free stream, a COS stream, an H.sub.2 S stream and a CO.sub.2 stream.

Abstract: A process for the removal of H.sub.2 S and COS from gas streams containing high concentrations of H.sub.2 S is described, the process being characterized by close integration of absorption and reaction techniques. In particular, the bulk of the H.sub.2 S is first absorbed from the gas stream, the balance being removed by oxidation after treatment of the stream to hydrolyze the COS.

Abstract: A gas stream containing CO.sub.2 and H.sub.2 S is contacted with an alkanolamine in a contacting zone. The rich solution is then selectively stripped in a stripping zone to produce a gas stream containing a higher CO.sub.2 :H.sub.2 S mole ratio than the initial stream. This stream can be recycled to the alkanolamine contacting zone. The partially stripped solution can be introduced into another stripping zone to provide a third gas stream which is rich in H.sub.2 S and lean in CO.sub.2 suitable as feed for a Claus Unit and a lean alkanolamine solution which can be recycled to the contacting zone.

Abstract: Regenerative process for the purification of a non-reacting industrial gas stream by removal of trace amounts of carbon dioxide therefrom, comprising contacting said gas stream with non-aqueous liquid solution of at least one member selected from the group consisting of: (a) hydroxides and weak acid salts of sodium, potassium, and lithium and (b) specific liquid aliphatic polyhydric alcohol; separating the purified industrial gas from the reaction products of said contacting step including said solution; increasing said reaction products stream to an elevated temperature up to 200.degree. C.; reducing the partial pressure of carbon dioxide in the vapor phase above said reaction product stream; separating carbon dioxide from said reaction product stream; and recycling the treated reaction product stream to said liquid body of said solution for contacting a further quantity of said industrial gas stream.

Abstract: The present invention relates to an alkaline salt promoter system comprising specific mixtures of sterically hindered monosubstituted alpha-amino acids and tertiary amino acids and its use in acid gas scrubbing processes. The preferred promoter system comprises a mixture of N-secondary butyl glycine and N-methyl-N-secondary butyl glycine.

Abstract: The selective removal of H.sub.2 S gas from a normally gaseous mixture containing H.sub.2 S and CO.sub.2 is accomplished by contacting the gaseous mixture with an absorbent solution comprising a diaminoether wherein at least one amino group is a tertiary amine whereby H.sub.2 S is selectively absorbed from the mixture.