A feed stream is flowed to a catalytic reactor. The catalytic reactor includes a non-thermal plasma and a catalyst. The feed stream includes hydrogen sulfide and carbon dioxide. The feed stream is contacted with the catalyst in the presence of the non-thermal plasma at a reaction temperature, thereby converting the hydrogen sulfide and the carbon dioxide in the feed stream to produce a product. The product includes a hydrocarbon and sulfur. The product is separated into a product stream and a sulfur stream. The product stream includes the hydrocarbon from the product. The sulfur stream includes the sulfur from the product.

Indoor and outdoor air purifier including:—a fan for suctioning air and conveying it into—an air treatment duct suitable to disintegrate the toxic and pollutant components present in the air and then reintroducing the air, purified by now, into the external environment through one of the grids; within the duct, at least the following being installed: ∘ filters in any alveolar ceramic alloy treated with a titanium dioxide TiO.sub.2 nano-coating suitable to disintegrate the pollutant substances by a photocatalytic process activated thanks to ∘ LED lights, each of which installed in proximity to a corresponding filter, suitable to start the pollutant molecules disintegration photocatalytic process, reintroducing only the harmless substances into the atmosphere.

In a device for separating methane from a gas mixture containing methane, carbon dioxide and hydrogen sulfide, comprising a gas compressor, two or three membrane separation stages downstream of the compressor and a hydrogen sulfide adsorber, comprising a bed of activated carbon having catalytic activity for oxidizing hydrogen sulfide with oxygen, arranged upstream of the membrane separation stages, oxygen content and relative humidity can be adjusted for optimum adsorption capacity of the hydrogen sulfide adsorber by recycling permeate from the second membrane separation stage, which receives the retentate of the first membrane separation stage, to a point upstream of the hydrogen sulfide adsorber.

Methods and systems are provided for treating the tail gas stream of a sulfur recovery plant. The methods including generating a tail gas stream from a sulfur recovery plant, treating the tail gas stream with a hydrogen sulfide removal unit and a hydrogen selective membrane unit, generating a stream low in hydrogen sulfide and a stream rich in hydrogen. The hydrogen sulfide rich stream is recycled to the sulfur recovery unit. The hydrogen selective membrane unit includes a glassy polymer membrane selective for hydrogen over hydrogen sulfide and carbon dioxide.

Methods and systems are provided for treating the tail gas stream of a sulfur recovery plant. The methods including generating a tail gas stream from a sulfur recovery plant, treating the tail gas stream with a hydrogen sulfide removal unit and a hydrogen selective membrane unit, generating a stream low in hydrogen sulfide and a stream rich in hydrogen. The hydrogen sulfide rich stream is recycled to the sulfur recovery unit. The hydrogen selective membrane unit includes a glassy polymer membrane selective for hydrogen over hydrogen sulfide and carbon dioxide.

In a device for separating methane from a gas mixture containing methane, carbon dioxide and hydrogen sulfide, comprising a gas compressor, two or three membrane separation stages downstream of the compressor and a hydrogen sulfide adsorber, comprising a bed of activated carbon having catalytic activity for oxidizing hydrogen sulfide with oxygen, arranged upstream of the membrane separation stages, oxygen content and relative humidity can be adjusted for optimum adsorption capacity of the hydrogen sulfide adsorber by recycling permeate from the second membrane separation stage, which receives the retentate of the first membrane separation stage, to a point upstream of the hydrogen sulfide adsorber.

A method for providing renewable natural gas (RNG) includes removing hydrogen sulfide and/or carbon dioxide from biogas to provide partially purified biogas, which may be stored in a mobile storage tank. The partially purified biogas is transported to a biogas upgrading facility, at least partially by truck, rail, or ship. At the biogas upgrading facility, the partially purified biogas is further purified to provide the RNG, which can be injected into a distribution system (e.g., natural gas grid) and/or provided for use in transportation.

The present disclosure provides a method for the separation of a gas constituent from a gaseous mixture. The disclosure also provides polyethylene glycol disubstituted siloxane based solvents for use in the method. These solvents are of use for pre-combustion CO.sub.2 capture and are capable of replacing glycol-based solvents while offering operation at a higher temperature region. These solvents are also of use for generation of hydrogen from reformed natural gas or syngas, adjusting CO/H.sub.2 ratio for Coal & Biomass to Liquids, removal of CO.sub.2 from syngas for coal & biomass to NH.sub.3/Fertilizer, natural gas sweetening, and upgrading of landfill and biogas.

A method for providing renewable natural gas (RNG) includes removing hydrogen sulfide and/or carbon dioxide from biogas to provide partially purified biogas, which may be stored in a mobile storage tank. The partially purified biogas is transported to a biogas upgrading facility, at least partially by truck, rail, or ship. At the biogas upgrading facility, the partially purified biogas is further purified to provide the RNG, which can be injected into a distribution system (e.g., natural gas grid) and/or provided for use in transportation.

A method for regenerating carbon dioxide and hydrogen sulfide from acid gas using a catalyst containing a group 2 element is provided. The method reduces the energy required for the regeneration process and allows for an efficient and cost-effective way to regenerate acid gas.