The present invention relates to a carbon dioxide absorbent comprising a triamine, a diamine and a dialkylene glycol dialkyl ether or trialkylene glycol dialkyl ether. The carbon dioxide absorbent according to the present invention can improve the carbon dioxide absorption capacity, absorption rate, and regeneration performance thereof simultaneously by using the triamine as a main absorbent, the diamine as a rate enhancer, the dialkylene glycol dialkyl ether or trialkylene glycol dialkyl ether as a fine disproportionation agent and a regeneration promoter.

The present invention relates to methods for improving carbon capture using entrained catalytic-particles within an amine solvent. The particles are functionalized and appended with a CO.sub.2 hydration catalyst to enhance the kinetics of CO.sub.2 hydration and improve overall mass transfer of CO.sub.2 from an acid gas.

The present invention relates to a carbon dioxide absorbent comprising an oxygen-containing diamine, a cyclodiamine and a polyalkylene glycol dialkyl ether. The carbon dioxide absorbent according to the present invention can improve the carbon dioxide absorption capacity, absorption rate and regeneration performance thereof simultaneously by using the oxygen-containing diamine as a main absorbent, the cylodiamine as a rate enhancer, and the polyalkylene glycol dialkyl ether as a fine disproportionation agent and a regeneration promoter.

The present invention relates to methods for improving carbon capture by providing particles within an amine solvent. The particles provide for increased turbulence at the interface between the counter-flowing gas and solvent, which allows for increased amine and carbamate salt diffusion between the liquid film and bulk.

An organic amine decarbonization solution includes: i) one or more organic amines serving as a carbon dioxide absorbent; and ii) an antioxidant. The antioxidant includes: a) one or more organometallic complexes of Formula [M.sub.x(L).sub.y]A.sub.n, wherein each M independently represents a central atom selected from the group consisting of transition metals, Group IVA metals and Group VA metals at a lower valence state; each L independently represents a bidentate or multidentate organic ligand with each ligating atom thereof being independently one of O, S, N and P; each A independently represents an uncoordinated counter-ion suitable for forming an outer sphere of a complex; x is 1, 2 or 3; y is 1, 2, 3, 4, 5, 6, 7 or 8; and n is 0, 1, 2, 3 or 4; and b) optionally one or more metal chelating agents.

Disclosed are a carbon dioxide absorbent composition in which an N-alkylaminoalkanol; a polyhydroxyamine-based compound; and ethylenediamine and/or diethylenetriamine are mixed, a method for preparing the same, and a method and an apparatus for carbon dioxide absorption/separation using the same. Since the carbon dioxide absorbent according to the present disclosure has superior carbon dioxide absorption capacity and remarkably lower absorbent recycling temperature as compared to the existing absorbents such as monoethanolamine, etc., total energy consumption in the capturing process can be reduced greatly. In addition, since carbon dioxide is recovered at low recycling temperature, contamination by water or absorbent vapor may be prevented.

An absorbent for absorbing CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S in a gas contains, as components, (a) a secondary linear monoamine, (b) a tertiary linear monoamine, and (c) a secondary cyclic diamine. When the concentration of the secondary linear monoamine (a) is more than 30% by weight and less than 45% by weight and the concentration of the tertiary linear monoamine (b) is more than 15% by weight and less than 30% by weight, absorbability of CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S is good, and releasability of CO.sub.2 or H.sub.2S that have been absorbed during regeneration of the absorbent is good. The amount of steam of a reboiler used during regeneration of the absorbent in a CO2 recovery unit can be thus reduced.

Disclosed herein is a method and system for CO.sub.2 removal from a gas stream using a diamine solvent having a Formula I

R.sup.1(R.sup.2)N-L.sup.1-NH—R.sup.3  Formula I. With respect to Formula I, each of R.sup.1 and R.sup.2 independently is aliphatic, cycloaliphatic, or R.sup.1 and R.sup.2 together with the nitrogen to which they are attached, form a heterocyclyl ring; L.sup.1 is aliphatic, cycloaliphatic, or L.sup.1 and R.sup.1 together with the nitrogen to which they are attached form a heterocyclyl ring; and R.sup.3 is aliphatic, cycloaliphatic, cycloalkylalkyl, or alkoxyalkyl. And/or the compound may have a viscosity of less than 75 cP at a CO.sub.2-loading of 40 mol % and at a temperature of 40° C.

A process for absorbing carbon dioxide from a gas stream containing carbon dioxide, including the steps of contacting the gas stream with an aqueous composition including a substituted heteroaromatic compound having a six-membered heteroaromatic ring with from 1 to 3 nitrogen atoms in the heteroaromatic ring and at least one substituent wherein at least one of the substituents is of formula —R.sup.1NH.sub.2 wherein R.sup.1 is selected from C.sub.1 to C.sub.6 alkylene and ethers of formula —R.sup.2—O—R.sup.3— wherein R.sup.2 and R.sup.3 are C.sub.1 to C.sub.3 alkylene

The absorption agent of the present invention contains water, an amine compound, and an organic solvent, and a value obtained by subtracting a solubility parameter of the organic solvent from a solubility parameter of the amine compound is 1.1 (cal/cm.sup.3).sup.1/2 or more and 4.2 (cal/cm.sup.3).sup.1/2 or less. The method for separation and recovery of an acidic compound of the present invention includes the steps of: bringing a mixed gas containing an acidic compound into contact with an absorption agent containing water, an amine compound, and an organic solvent to absorb the acidic compound into the absorption agent; causing the absorption agent that has absorbed the acidic compound to be phase-separated into a first phase containing the acidic compound in a high content and a second phase containing the acidic compound in a low content; and heating the first phase to release the acidic compound from the first phase.