An integrated amine and redox gas treatment system is configured to treat an influent hydrocarbon containing stream. The system includes a reduction oxidation unit connected directly downstream of an amine unit. The amine unit is configured to separate the influent fluid stream into a first amine effluent stream including hydrocarbons and a second amine effluent stream including a connection pressure and comprising CO.sub.2. The reduction oxidation unit is configured to receive the second amine effluent stream from the amine unit and operate at the connection pressure while releasing a reduction oxidation effluent stream including purified CO.sub.2. The connection pressure includes a single pressure or a plurality of pressures at which both the amine unit and the reduction oxidation unit are configured to operate.

A gas treatment system configured to purify an influent gas stream including a hydrocarbon gas and a hydrogen sulfide gas comprises a reduction unit and an oxidation unit. The reduction unit includes at least one eductor configured to contact the influent gas stream with a primary stream including aqueous reducing reagent and release a purified hydrocarbon gas stream and a contacted primary stream including elemental sulfur. The oxidation unit includes at least one eductor configured to contact an oxidizing agent stream and a secondary stream including the primary stream and contacted primary stream and output a regenerated redox reagent stream.

A method and a system for abating hydrogen sulfide (H.sub.2S) and carbon dioxide (CO.sub.2) from H.sub.2S and CO.sub.2 rich gas mixtures such as geothermal non-condensable gas mixtures (NCG). The H.sub.2S and CO.sub.2 gas is separated from the remaining gases contained in the H.sub.2S and CO.sub.2 rich gas mixtures by pressurizing the gas stream and feeding it into an absorption column where H.sub.2S and CO.sub.2 are preferentially dissolved in a water stream, resulting in water stream rich in H.sub.2S and CO.sub.2. The H.sub.2S and CO.sub.2 rich water stream may then be re-injected into a geological reservoir or used for pH modification of another water stream of geological origin.

Apparatuses, systems, and methods for removing acid gases from a gas stream are provided. Gas streams include waste gas streams or natural gas streams. The methods include obtaining a hypochlorite and a carbonate or bicarbonate in an aqueous mixture, and mixing the aqueous mixture with the gas stream to produce sulfates or nitrates from sulfur-based and nitrogen-based acidic gases. Some embodiments of the present disclosure are directed to produce the carbonate and/or bicarbonate scrubbing reagent from CO.sub.2 in the gas stream. Still others are disclosed.

A composite amine absorbent to absorb at least one of CO.sub.2 and H.sub.2S in a gas includes: a chain monoamine; a diamine; a cyclic compound represented by the following chemical formula: ##STR00001##
where R.sup.1: any one of hydrogen, a hydrocarbon group having a carbon number of 1 to 4, and a hydroxyalkyl group, R.sup.2: oxygen or NR.sup.3, and R.sup.3: any one of hydrogen, a hydrocarbon group having a carbon number of 1 to 4, and a hydroxyalkyl group; and water.

A method for treating an industrial gas stream that includes acid gases includes contacting the industrial gas stream with an aqueous liquid absorption medium in a gas/liquid absorber. The aqueous liquid absorption medium includes at least a tertiary alkanolamine having the General Formula (I) in an amount for 10 wt % to 90 wt % and water in an amount from 10 wt % to 90 wt %, based on a total weight of the aqueous liquid absorption medium.

A treatment system for remediating some forms of sulfur, CO.sub.2, and other contaminants/impurities from a gas stream includes at least one of a process vessel and a treatment coil. Each of the vessel and treatment coil have internals, different in design from each other, which promote intimate mixing and extended contact time between a treatment composition and a gas being treated. The vessel, which additionally facilitates vapor/liquid separation, operates about one-half to two-thirds full of liquid treatment composition. In some embodiments, the treatment coil is a serpentine arrangement of piping, into which the atomized treatment composition is injected on a continuous basis.

Provided are a reclaimer that introduces a part of an absorbent that has absorbed CO.sub.2 or H.sub.2S in a flue gas through an introduction line and stores the absorbent, a heating section that heats the absorbent stored in the reclaimer to obtain recovered vapor, and a mixing tank disposed on the introduction line through which the absorbent is introduced into the reclaimer, and which introduces an absorbent (lean solution) and an alkaline agent for mixing thereof.

A treatment system for remediating some forms of sulfur, CO.sub.2, and other contaminants/impurities from a gas stream includes at least one of a process vessel and a treatment coil. Each of the vessel and treatment coil have internals, different in design from each other, which promote intimate mixing and extended contact time between a treatment composition and a gas being treated. The vessel, which additionally facilitates vapor/liquid separation, operates about one-half to two-thirds full of liquid treatment composition. In some embodiments, the treatment coil is a serpentine arrangement of piping, into which the atomized treatment composition is injected on a continuous basis.

A method for treating an offgas produced in the processing of a renewable feedstock, includes hydrotreating a renewable feedstock to produce an effluent having a hydrotreated liquid and a vapour phase. The effluent vapour phase contains hydrogen, carbon dioxide, hydrogen sulphide and carbon monoxide. The effluent is separated into a liquid stream and an offgas streams. The offgas stream, containing carbon dioxide and hydrogen sulphide is directed to abiological desulfurization unit where a majority of the hydrogen sulphide is converted to elemental sulphur and a CO2-rich gas stream is produced.