The present invention relates to a biocompatible task specific hybrid solvent (TSHS) composition that synergistically increases the carbon capture efficiency and utilizes less energy for CO.sub.2 desorption over the existing solutions. Further, the process of synthesizing such composition is discussed in this disclosure. Also, the present disclosure provides a process that involves a task specific hybrid solvent (TSHS) composition for selective capturing CO.sub.2 from any gaseous stream.

A system and method for processing unconditioned syngas first removes solids and semi-volatile organic compounds (SVOC), then removes volatile organic compounds (VOC), and then removes at least one sulfur containing compound from the syngas. Additional processing may be performed depending on such factors as the source of syngas being processed, the products, byproducts and intermediate products desired to be formed, captured or recycled and environmental considerations.

The use of an amine of the formula (I) ##STR00001##
in which the R.sup.1 to R.sup.5 radicals are each as defined in the description, and an absorbent and a process for removing acidic gases from a fluid stream, especially for selectively removing hydrogen sulfide over carbon dioxide. The invention also relates to particular amines suitable for selective removal of hydrogen sulfide. Absorbents based on amines of the formula (I) have high selectivity, high loading capacity and good regeneration capacity.

A method for treating sulfur contaminants is provided. The method comprises introducing a methylmorpholine-N-oxide solution to a vessel, wherein the vessel comprises a water layer and a gas layer, wherein the water layer and the gas layer comprise the hydrogen sulfide; introducing methylmorpholine-N-oxide into the water layer; and treating the water layer by allowing the methylmorpholine-N-oxide to react with the hydrogen sulfide.

An acidic gas absorbent contains an amine compound of formula (1) and a cyclic amino compound of formula (2) or (3): ##STR00001## ##STR00002## ##STR00003##
where in the formulas, each R.sup.1 is independently a straight-chain hydroxyalkyl having a hydroxy at the terminal, R.sup.2 is a branched-chain secondary alkyl group, R.sup.3 and R.sup.4 are hydrogen, hydroxy, a hydroxyalkyl or aminoalkyl, provided that at least one of R.sup.3 and R.sup.4s is a hydroxyalkyl or aminoalkyl, each p is independently an integer of 2 to 4, each R.sup.5 is independently hydrogen, hydroxy, or a hydroxyalkyl or aminoalkyl, provided that at least one of R.sup.5s is a hydroxyalkyl or aminoalkyl, and q is an integer of 3 to 8.

A method of scavenging acid sulfide species from an industrial or environmental material, the method comprising contacting the material with: (a) propenal and/or maleimide and/or ethyl-2-chloroacetoacetate; and (b) a base.

A method for treating sulfur contaminants is provided. The method comprises introducing a methylmorpholine-N-oxide solution to a vessel, wherein the vessel comprises a water layer and a gas layer, wherein the water layer and the gas layer comprise the hydrogen sulfide; introducing methylmorpholine-N-oxide into the water layer; and treating the water layer by allowing the methylmorpholine-N-oxide to react with the hydrogen sulfide.

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 sulfur dioxide absorbent that is an ionic liquid including a solvent; and a salt of a diamine compound that is substituted with a hydroxyl group and has a chemical formula 1 to 3 below dissolved in the solvent: ##STR00001## where, in Chemical Formula 1 and 2, R.sub.1-R.sub.4 are the same or different and each is independently selected from the group consisting of H, a C1-C6 alkyl, and a C1-C6 alkoxy; and where, in Chemical Formula 1 to 3, X is selected from the group consisting of Cl, Br, I, MeSO.sub.3, CF.sub.3SO.sub.3, HCO.sub.2, CF.sub.3CO.sub.2 and CH.sub.3CO.sub.2; and n is an integer of 1-10. The sulfur dioxide absorbent is constituted to selectively absorb sulfur dioxide and sulfurous acid (H.sub.2SO.sub.3) formed by combination of sulfur dioxide with water, not CO.sub.2.

A method for treating sulfur contaminants is provided. The method comprises introducing a methylmorpholine-N-oxide solution to a vessel, wherein the vessel comprises a water layer and a gas layer, wherein the water layer and the gas layer comprise the hydrogen sulfide; introducing methylmorpholine-N-oxide into the water layer; and treating the water layer by allowing the methylmorpholine-N-oxide to react with the hydrogen sulfide.