Disclosed is a process for regenerating a hybrid solvent used to remove contaminants from a fluid stream and to provide an improved yield of purified fluid. Said process comprises at least one purification unit (12) and at least one regeneration unit (40) wherein condensed water (72) from the regeneration unit is combined with the regenerated lean hybrid solvent (55) prior to reuse in the purification unit and none of the condensed water is recycled into the regeneration unit.

A system and a process for capturing Carbon Dioxide (CO.sub.2) from flue gases are disclosed. The process comprises feeding a flue gas comprising CO.sub.2 to at least one Rotary Packed Bed (RPB) absorber rotating circularly. A solvent may be provided through an inner radius of the RPB absorber. The solvent may move towards an outer radius of the RPB absorber. The solvent may react with the flue gas in a counter-current flow. The process further includes passing the flue gas through at least one of a water wash and an acid wash to remove traces of the solvent present in the flue gas. Finally, the solvent reacted with the CO.sub.2 may be thermally regenerated for re-utilizing the solvent back in the process.

In a process for removal of acid gases from a fluid stream the fluid stream is contacted with an absorbent to obtain a treated fluid stream and a laden absorbent. The absorbent comprises a diluent and a compound of the general formula (I) wherein R.sup.1 is C.sub.1-C.sub.3-alkyl; R.sup.2 is C.sub.1-C.sub.3-alkyl; R.sup.3 is selected from hydrogen and C.sub.1-C.sub.3-alkyl; and R.sup.4 is selected from hydrogen and C.sub.1-C.sub.3-alkyl

##STR00001##

A hybrid post-combustion carbon dioxide capture system for capturing carbon dioxide from a flue gas includes a compressor adapted to produce a compressed flue gas stream, a membrane-based carbon dioxide separation unit configured to receive a first portion of the compressed flue gas stream from the compressor, and an aqueous-based carbon dioxide capture unit configured to receive a second portion of the compressed flue gas stream from the compressor whereby the compressed flue gas stream is processed in parallel by the membrane-based carbon dioxide separation unit and the aqueous-based carbon dioxide capture unit.

A system to abate an emission stream from a semiconductor manufacturing process is disclosed. The system includes an abatement apparatus, such as a gas scrubber, to remove hazardous and toxic gas species from the emission stream and to yield an emission having carbon dioxide. The system condenses the emission having carbon dioxide to an effluent, and transmits the effluent through a reduction tower. The reduction tower catalyzes a chemical reaction which absorbs carbon dioxide from the effluent using a solution and yields an exhaust substantially free of carbon dioxide. The reduction tower is coupled to an exchanger which catalyzes a thermogenic reaction to release absorbed carbon dioxide from the solution. The system may include a closed-loop system that transmits solution substantially free of carbon dioxide from the exchanger and through the reduction tower to absorb carbon dioxide from additional effluent.

The invention relates to a regeneration system for a carbon-rich amine solution produced in carbon dioxide capture from a mixed gas and a method for using the same. This regeneration system is composed of a bipolar membrane electrodialysis apparatus and a carbon dioxide removal apparatus, wherein the bipolar membrane electrodialysis apparatus is composed of a bipolar membrane electrodialysis membrane stack fixed between an anode plate and a cathode plate, the carbon dioxide removal apparatus is composed of one or more hollow fiber membrane contactors, the inlet of the carbon dioxide removal apparatus is fluidly connected with the outlet of the acid chamber of the bipolar membrane electrodialysis apparatus, the outlet of the carbon dioxide removal apparatus is fluidly connected with the acid solution storage tank, and carbon dioxide gas removed by the carbon dioxide removal apparatus is collected in a carbon dioxide storage tank. In the invention, by treating a carbon-rich amine solution having heat stable salts with a combined apparatus of bipolar membrane electrodialysis and carbon dioxide removal, individual operation for conventional heat stripping and organic amine regeneration is avoided, the energy consumption of carbon capture is reduced, the process flow is simplified, and the overall net capture efficiency of carbon dioxide is improved.

The invention relates to a system or method for capturing a molecule of interest contained in an industrial gaseous effluent, enabling the implementation of a regeneration step (120) in at least one regeneration section (30), a condensation step (150) in at least one condensation section (40), and wherein a step (130) of compressing the gas mixture comprising a solvent and the molecule of interest upstream of the condensation section (40) so that the pressure in the at least one condensation section (40) is at least three times higher than the pressure in the at least one regeneration section (30). The method further comprises a heat transfer step (140) between the at least one condensation section (40) and the at least one regeneration section (30).

A water-lean carbon dioxide absorbent according to the present invention comprises a cyclodiamine and a polyalkylene glycol alkyl ether and further comprises an alkanolamine, wherein the absorbent shows an excellent reaction rate with carbon dioxide, is resistant to degradation due to oxygen and heat, and can greatly reduce energy consumption due to latent heat of water when regenerated, and thus leads to a water-lean carbon dioxide absorbent with improved regeneration efficiency.

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.

The embodiment provides an acidic gas absorbent. The acidic gas absorbent comprises an amine compound of the formula (1) and a cyclic amino compound of the formula (2) or (3):

##STR00001##

[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.]

The acidic gas removal method and apparatus according to the embodiment uses the above acidic gas absorbent.