The present invention relates to a method for continuous removal of carbon dioxide, the method comprising the steps of: a) preparing an aqueous solution containing an amine-based compound and an acidic calcium compound; b) bringing a gas containing carbon dioxide to be treated into contact with the aqueous solution to prepare a calcium carbonate precipitate; and c) recovering the calcium carbonate and then adding a basic calcium compound to the residual aqueous solution, wherein after step c), step b) and step c) are repeatedly performed. The removal of carbon dioxide by the method of the present invention has advantages of requiring low energy and being capable of mineralizing and removing carbon dioxide at a fast rate without a separate time for induction.

An aqueous solvent composition is provided, comprising a nucleophilic component having one or more sterically unhindered primary or secondary amine moieties, a Brønsted base component having one or more basic nitrogen moieties, a water-soluble organic solvent, and water. A biphasic composition is provided, comprising one or more carbamate compounds, one or more conjugate acids of Brønsted base, a water-soluble organic solvent, and water. A biphasic CO.sub.2 absorption process is also provided, utilizing the biphasic solvent composition.

A process for removing hydrogen sulfide and carbon dioxide from a fluid stream comprises a) an absorption step in which the fluid stream is contacted with an absorbent comprising an aqueous solution (i) of an amine of the general formula (I) ##STR00001##
in which R.sub.1, R.sub.2 and R.sub.3 are each independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.4 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.5 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; X is OH or NH(CR.sub.1R.sub.2R.sub.3); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and optionally (ii) at least one tertiary amine, where the molar ratio of (i) to (ii) is greater than 0.05; wherein at least 90% of the hydrogen sulfide is removed from the fluid stream and selectivity for hydrogen sulfide over carbon dioxide is not greater than 8, wherein a CO.sub.2— and H.sub.2S-laden absorbent is obtained; b) a regeneration step in which at least a substream of the CO.sub.2— and H.sub.2S-laden absorbent is regenerated and a regenerated absorbent is obtained; and c) a recycling step in which at least a substream of the regenerated absorbent is recycled into the absorption step a). The process allows a high level of hydrogen sulfide removal with a simultaneously high coabsorption of carbon dioxide.

A composite amine absorbent according to the present invention is an absorbent for absorbing CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S in a gas. The absorbent is obtained by dissolving (1) a linear monoamine, (2) a diamine, and (3) propylene glycol alkyl ether, for example, represented by the following chemical formula (I) in water. In the composite amine absorbent, the components complexly interact, and the synergistic effect thereof provides good absorbability of CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S and good releasability of CO.sub.2 or H.sub.2S absorbed during regeneration of the absorbent. Furthermore, the amount of water vapor in a reboiler 26 used during regeneration of the absorbent in a CO.sub.2 recovery unit 12 can be reduced.

R.sup.1—O—(R.sup.2—O).sub.n—R.sup.3  (I)

The embodiments provide an acidic gas absorbent having low diffusibility, an acidic gas removal method, and an acidic gas removal apparatus. The acidic gas absorbent according to the embodiment comprises: an amine compound having a vapor pressure of 0.001 to 10 Pa at 20° C.; a water-soluble polymer compound having a mass-average molecular weight of 900 to 200000 and not containing a functional group having a pKa value greater than 7 except for hydroxy; and water.

The present disclosure relates to an absorber column apparatus for removing a selected component of a gas. The apparatus may have a first zone, a second zone and a third zone, wherein the first and third zones form a first domain through which a first fluid laden with a select gaseous component to be removed therefrom flows along concurrently with a second fluid. The second fluid at least substantially removes the select gaseous component from the first fluid to create a third fluid. The first fluid leaves the absorber column as a fourth fluid with the select gaseous component at least substantially removed therefrom. The second zone forms an active packing zone including a structure which forms an independent second domain in thermal communication with the first domain. The second receives a quantity of the third fluid and channels it through the second zone to help cool at least one of the first and second fluids.

The embodiments provide an acidic gas absorbent having low diffusibility, an acidic gas removal method employing the acidic gas absorbent, and also an acidic gas removal apparatus employing the absorbent. The acidic gas absorbent according to the embodiment comprises: a particular tertiary amine compound, such as, an alkyl dialkanol amine or a hydroxyalkyl piperazine; a halogen-free ionic surfactant; and an aqueous solvent. The embodiments provide not only the acidic gas absorbent but also an acidic gas removal method and apparatus employing the acidic gas absorbent.

The combined acid gas removal and water filtration system (10) removes sour gases, such as hydrogen sulfide (H2S) and carbon dioxide (CO2), from an input gaseous hydrocarbon stream (FG), as well as producing purified water (TW). The acid gas removal system (10) has a contactor (12) for contacting the input gaseous stream (FG) with an absorption liquid solvent (ALS), and a stripper (24) for recycling the absorption liquid solvent (ALS) and removing acidic gases (AG) therefrom. A first heat exchanger (22) heats used absorption liquid solvent (UALS) output from the contactor (12) prior to injection into the stripper (24). A second heat exchanger (26) cools recycled absorption liquid solvent (RALS) using a refrigerant (R) before injection back into the contactor (12). The refrigerant (R) is coupled with an absorber (84), which receives a dilute ethanolic draw solution (DDS) from a forward osmosis filtration system (72), producing purified water (TW).

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.

A composite material for gas capture, notably CO.sub.2 capture and storage. The composite material includes a mixture of a solid or liquid reactive filler and a gas-permeable polymer such that the reactive filler forms micron-scale domains in the polymer matrix.