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 system and method for removing sulfur compounds from gas, including providing a feed gas having sulfur compounds including hydrogen sulfide (H.sub.2S) to a sulfur recovery unit (SRU) that has a furnace or a non-thermal plasma (NTP) reactor, discharging an SRU tail gas having H.sub.2S from the SRU to a tail gas treatment (TGT) unit having a hydrogenation reactor, a quench tower, and a TGT NTP reactor, converting sulfur compounds in the SRU tail gas in the hydrogenation reactor into H.sub.2S, discharging a process gas having H.sub.2S from the hydrogenation reactor to the quench tower and removing water vapor from the process gas in the quench tower, discharging an overhead gas having H.sub.2S from the quench tower to the TGT NTP reactor, and converting H.sub.2S in the TGT NTP reactor into hydrogen (H.sub.2) and elemental sulfur.

Indoor and outdoor air purifier including:a fan for suctioning air and conveying it intoan 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.

An improved process for removing acid gases from raw biogas streams, such as biogas from landfills or biogas from controlled anaerobic digestion, provides for efficient H.sub.2S removal combined with carbon dioxide removal. The biogas is treated in a biological hydrogen sulfide removal system integrated with a multi-stage membrane gas separation system. The combined system provides for efficient acid gas removal while simultaneously limiting oxygen carryover into the treated product stream by beneficially utilizing oxygen in the biological desulfurization system.