The composite amine absorbing solution according to the present invention absorbs CO.sub.2 or H.sub.2S or both in a gas, and is obtained by dissolving a linear monoamine, a diamine, and an amide group-containing compound in water. By adopting this composite amine absorbing solution, the composites are interacting in a composite manner, due to an integrated effect of the components, the absorption property of CO.sub.2 or H.sub.2S or both is favorable, the desorption properties of the CO.sub.2 or H.sub.2S absorbed when regenerating the absorbing solution become favorable, and the amount of steam from a reboiler used when regenerating the absorbing solution in a CO.sub.2 recovery device can be reduced.

The composite amine absorbing solution according to the present invention absorbs CO.sub.2 or H.sub.2S or both in a gas, and is obtained by dissolving a linear monoamine, a diamine, and an amide group-containing compound in water. By adopting this composite amine absorbing solution, the composites are interacting in a composite manner, due to an integrated effect of the components, the absorption property of CO.sub.2 or H.sub.2S or both is favorable, the desorption properties of the CO.sub.2 or H.sub.2S absorbed when regenerating the absorbing solution become favorable, and the amount of steam from a reboiler used when regenerating the absorbing solution in a CO.sub.2 recovery device can be reduced.

A method may include: contacting a feed stream comprising carbonyl sulfide with an aqueous stream comprising water in the presence of a carbonyl sulfide hydrolysis catalyst, wherein the carbonyl sulfide hydrolysis catalyst comprises a solid support and a polyamine covalently bonded to the solid support; and hydrolyzing at least a portion of the carbonyl sulfide to produce at least hydrogen sulfide.

To provide a sulfur-containing complex having few impurities, a method for producing the complex at a higher production efficiency, and a method for producing a solid electrolyte using the complex, a sulfur-containing complex, containing a lithium sulfide and a lithium halide, exhibiting, in X-ray diffractometry using a CuK ray, the diffraction angle of the peak of lithium halide shifting toward the diffraction angle of the peak of lithium sulfide, and not containing an oxygen-containing lithium halide represented by Li.sub.3OX (where X represents a halogen element) is provided. And a production method for a sulfur-containing complex including heating a solution containing a lithium hydrosulfide and a lithium halide in the presence of hydrogen sulfide is also provided.

To provide a sulfur-containing complex having few impurities, a method for producing the complex at a higher production efficiency, and a method for producing a solid electrolyte using the complex, a sulfur-containing complex, containing a lithium sulfide and a lithium halide, exhibiting, in X-ray diffractometry using a CuK ray, the diffraction angle of the peak of lithium halide shifting toward the diffraction angle of the peak of lithium sulfide, and not containing an oxygen-containing lithium halide represented by Li.sub.3OX (where X represents a halogen element) is provided. And a production method for a sulfur-containing complex including heating a solution containing a lithium hydrosulfide and a lithium halide in the presence of hydrogen sulfide is also provided.

Dry-scrubbing media compositions, methods of preparation and methods of use are provided. The compositions contain activated alumina and magnesium oxide. Optionally, activated carbon and other impregnates, such as hydroxides of group 1A metals, are included. The compositions exhibit improved efficiency and capacity for the removal of compounds, such as hydrogen sulfide, from an air-stream. The compositions are particularly useful for reducing or preventing the release of toxic gaseous compounds from the areas such as landfills, petroleum storage areas, refineries, drinking water systems, sewage treatment facilities, swimming pools, hospital morgues, animal rooms, and pulp and paper production sites.

Systems and methods for removing hydrogen sulfide from an ammonia stream in the NH3 purification and liquefaction stage of a conventional two-column sour water stripping system using an adsorbent bed.

A process for recovering sulfur from a sour gas is provided. The process includes the steps of: providing the sour gas to a membrane separation unit having a carbon dioxide-selective membrane that comprises a perfluoropolymer, wherein the sour gas comprises carbon dioxide and at least 1 mol % hydrogen sulfide; separating the sour gas using the carbon dioxide-selective membrane in the membrane separation stage to obtain hydrogen sulfide-enriched gas and hydrogen sulfide-stripped gas, wherein the hydrogen sulfide-enriched gas has a hydrogen sulfide concentration of at least 20 mol %, and wherein the hydrogen sulfide-stripped gas comprises carbon dioxide; and processing the hydrogen sulfide-enriched gas in a sulfur recovery unit to obtain sulfur.

A biogas cleaning method for purifying a biogas waste stream to form a combustible clean biofuel uses a biogas cleaning system that includes a gas control system, a deoxidizer catalyst bed, a hydrosulfurization catalyst bed, a hydrogen sulfide adsorption bed and a thermal sensor controller. The biogas cleaning method includes using a biogas source to introduce a biogas waste stream into the biogas cleaning system, blending hydrogen with the biogas waste stream, combusting the blended hydrogen and biogas stream to remove oxygen, hydrogenating the heated biogas waste stream to convert sulfur species to hydrogen sulfide and adsorbing the hydrogen sulfide from the biogas stream. In some embodiments, a biogas cleaning system also includes a sulfur polisher adsorption bed, a chlorine removal adsorption bed, a siloxane removal adsorption bed, a heat exchanger loop and a biogas precooler. Some embodiments of a biogas cleaning method can also include precooling the biogas waste stream, adsorbing siloxanes from the biogas waste stream and adsorbing hydrogen chloride from the biogas stream.

A biogas cleaning method for purifying a biogas waste stream to form a combustible clean biofuel uses a biogas cleaning system that includes a gas control system, a deoxidizer catalyst bed, a hydrosulfurization catalyst bed, a hydrogen sulfide adsorption bed and a thermal sensor controller. The biogas cleaning method includes using a biogas source to introduce a biogas waste stream into the biogas cleaning system, blending hydrogen with the biogas waste stream, combusting the blended hydrogen and biogas stream to remove oxygen, hydrogenating the heated biogas waste stream to convert sulfur species to hydrogen sulfide and adsorbing the hydrogen sulfide from the biogas stream. In some embodiments, a biogas cleaning system also includes a sulfur polisher adsorption bed, a chlorine removal adsorption bed, a siloxane removal adsorption bed, a heat exchanger loop and a biogas precooler. Some embodiments of a biogas cleaning method can also include precooling the biogas waste stream, adsorbing siloxanes from the biogas waste stream and adsorbing hydrogen chloride from the biogas stream.