The present invention relates to a novel phase transfer solvent composition for enhanced CO.sub.2 and/or H.sub.2S capture from flue gas and biogas having various gaseous compositions. Further, the present invention provides a process of preparing the phase transfer solvent composition of the present invention.

Multiple risers are provided to perform different steps in a biogas water wash process. The risers may include absorption risers, flashing risers, and stripping risers. In each riser, the inlets to provide fluids to the riser and outlets to remove fluids from the risers are provided at one end of the riser. Each riser may then be located substantially below grade such that the end with the inlets and outlets is accessible at or just above the ground level. The risers within each step of the water wash process may be connected in series, parallel, or a combination thereof. The risers may also be constructed of a polyethylene material to reduce cost and weight of the water wash system.

Several embodiments of the invention relate generally to a system and methods for the treatment of gaseous emissions comprising methane and one or more non-methane compounds that can influence the metabolism of methane-oxidizing microorganisms. In several embodiments, there is provided a system and methods for the treatment of methane emissions through the use of methanotrophic microorganisms to generate functionally consistent and harvestable products. Certain embodiments of the invention are particularly advantageous because they reduce environmentally-destructive methane emissions and produce harvestable end-products.

The present invention relates to a biomimetic-hybrid solvent system for simultaneous capture of H.sub.2S and CO.sub.2 from any gaseous composition. The present invention also relates to a process for upgradation of biogas to bio CNG by removing gaseous contaminants, including microbial removal of H.sub.2S, to obtained purified CO.sub.2. The biomimetic-hybrid solvent system contains three components selected from tertiary amine compounds, a functional colloidal fluid, and an enzyme mimic.

Methods and systems for capture of CO.sub.2 from a hydrated gaseous stream are described. Systems can be utilized for direct air capture of CO.sub.2 and incorporate a low energy temperature-vacuum swing adsorption (TVSA) process. A TVSA process can include a multi-step CO.sub.2 capture bed regeneration process that includes depressurization of the bed, heating of the bed, venting and purging of the bed, and cooling of the bed. Multiple beds can be cycled between CO.sub.2 capture and regeneration, during which captured CO.sub.2 is recovered. Off-gas from a CO.sub.2 capture bed can be used in regenerating a parallel bed for increased efficiency.

Device for the production of at least partially desulfurized biogas comprising: a digester, a means for continuous introduction of biochar into the digester and a membrane separation unit placed on the stream of biogas exiting from the digester and comprising at least one membrane allowing the sulfur-comprising products to permeate.

A plant for producing at least partially desulfurized biogas, comprising a biomass digester and/or post-digester, the digester and/or post-digester comprising: a chamber (1) comprising the biomass (2) and the gas space (3), and a system (6) for injecting an oxidizing gas into the gas space,
wherein the injection system comprises a tubular means (4) comprising a T-shaped portion the vertical bar of which is placed in the axis of symmetry of the chamber and the horizontal bar of which has micro-injectors (5).

A bioproduct manufacturing system is disclosed. The system comprises a hollow-fiber primary membrane gas absorber comprising a shell side and a lumen, wherein the primary membrane gas absorber is configured to receive a carbonate salt-based solvent on the shell side and a gas mixture comprising oxygen, nitrogen, and carbon dioxide in the lumen, at least one runway algal cassette reactor-photobioreactor, and a growth medium circulating between the primary membrane gas absorber and the at least one runway algal cassette reactor-photobioreactor. The at least one runway algal cassette reactor-photobioreactor comprises at least one growth chamber coupled to and in fluid communication with a headspace channel so as to define and interior volume, a first condenser coupled to and in fluid communication with the headspace channel, and a harvest line in fluid communication with the at least one growth chamber and coupled to a filter.

Plant for producing at least partially desulfurized biogas, comprising a biomass digester and/or post-digester, the digester and/or post-digester comprising: a chamber comprising the biomass and the gas space, and a means for introducing an oxidizing gas,

characterized in that the portion of the inner wall of the chamber situated at the level of the gas space exhibits expansions and/or hollows.

Plant for producing at least partially desulfurized biogas, comprising a biomass digester and/or post-digester, the digester and/or post-digester comprising: a chamber (1) in which an anaerobic digestion of the biomass takes place, leading to the production of biogas (2) and of digestate (3), a means for introducing an oxidizing gas, a desulfurization net (4) placed horizontally and fastened in the upper part of the chamber, and ropes (5) attached to said desulfurization net and which hang down to the biogas-digestate interface.