# US 2021/0275959 A1 · Acid gas removal apparatus and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0275959 A1 - Document ID: US20210275959A1 - Status: Published application - Kind: A1 - Application number: 17/012,793 - Filed: 2020-09-04 - Published: 2021-09-09 - Earliest claimed: 2020-03-09 - Assignees: KABUSHIKI KAISHA TOSHIBA; Minato-Ku, Japan - Applicants: Kabushiki Kaisha Toshiba - Inventors: Hitomi SAITO; Kenji SANO; Toshihiro IMADA; Akiko SUZUKI - Web page: https://patentgrep.com/patent/US20210275959A1 ## CPC - B01D 53/1425: {Regeneration of liquid absorbents} - B01D 53/1475: {Removing carbon dioxide} - B01D 53/18: Absorbing units; Liquid distributors therefor (B01D3/16, B01D3/26, B01D3/30 take precedence; packing elements B01J19/30, B01J19/32) - B01D 53/62: Carbon oxides - B01D 53/78: with gas-liquid contact - B01D 53/1468: {Removing hydrogen sulfide} - B01D 53/265: {by refrigeration (condensation)} - B01D 2252/204: Amines - B01D 2252/20431: Tertiary amines - B01D 2252/60: Additives - B01D 2256/22: Carbon dioxide - B01D 2257/304: Hydrogen sulfide - B01D 2257/504: Carbon dioxide - B01D 2258/0283: Flue gases - Y02C 20/40: of CO2 - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] ## Abstract The embodiment provides a composite that allows the release of acid gas, even the continuous release of acid gas, at low temperature and with a high acid-gas release rate in a regeneration tower of an acid gas removal apparatus, and a regenerator and an acid gas removal apparatus, in both of which the composite is used, and a method of acid gas removal. The composite according to the embodiment is capable of separating an acid gas from an acid gas absorbent, which has absorbed the acid gas, to regenerate the acid gas absorbent, wherein the composite contains an inorganic layered compound and an aluminum-containing oxide. Also provided are a regenerator using the composite to regenerate an acid gas absorbent that has absorbed an acid gas by allowing the acid gas absorbent to release the acid gas, and an acid gas removal apparatus equipped with the regenerator. ## Claims ### Claim 1 A composite capable of separating an acid gas from an acid gas absorbent, regenerating the absorbent, and comprising an inorganic layered compound and an aluminum-containing oxide. ### Claim 2 (depends on 1) The composite according to claim 1, wherein the inorganic layered compound is a hydrotalcite-like compound. ### Claim 3 (depends on 1) The composite according to claim 1, wherein the inorganic layered compound is represented by the following general formula (HT-a) or (HT-b): [M1+a1M3+a2(OH)6][An−(3-2a1)/n.maH2O] (HT-a), [M22+b1M33+b2(OH)2][An−b2/n.mbH2O] (HT-b) (wherein M1+ represents a univalent metal ion; M22+ represents a divalent metal ion; M33+ represents a trivalent metal ion; An− represents an anion with a valence of n; 0.70≤a1≤1.00; 2.7≤(a1+a2)≤3.3; 0.10≤b2≤0.40; 0.90≤(b1+b2)≤1.1; and ma and mb are numbers each representing the amount of interlayer water). ### Claim 4 (depends on 3) The composite according to claim 3, wherein the univalent metal ion (M1+) is selected from the group consisting of Li+, Na+, K+, Rb+, and Cs+, and the divalent metal ion (M22+) is selected from the group consisting of Mg2+, Ca2+, Zn2+, Fe2+, Cu2+, Mn2+, Ni2+, and CO2+, and the trivalent metal ion (M32+) is selected from the group consisting of Al3+, Cr3+, Fe3+, Co3+, Ga3+, V3+, and In3+. ### Claim 5 (depends on 4) The composite according to claim 4, wherein the inorganic layered compound contains Li+ as the univalent metal ion and Al3+ as the trivalent metal ion. ### Claim 6 (depends on 1) The composite according to claim 1, wherein the aluminum-containing oxide further contains at least one metal selected from the group consisting of Ti, Si, and Ce. ### Claim 7 (depends on 1) The composite according to claim 1, wherein the aluminum-containing oxide is porous. ### Claim 8 (depends on 1) The composite according to claim 1, wherein, in an X-ray diffraction profile of the composite, the ratio (I2/I1) of the maximum intensity I2 of a diffraction line in the 2θ range from 40 to 45° to the maximum intensity I1 of a diffraction line in the 2θ range from 10 to 15° is from 0.1 to 1.0. ### Claim 9 (depends on 1) The composite according to claim 1, wherein the composite has platy or laminar structures derived from the inorganic layered compound. ### Claim 10 (depends on 1) The composite according to claim 1, wherein the composite has platy or laminar structures derived from the inorganic layered compound and powder structures derived from the aluminum-containing oxide. ### Claim 11 (depends on 1) A regenerator of regenerating an acid gas absorbent, comprising the composite according to claim 1, wherein the acid gas absorbent that has absorbed an acid gas is brought into contact with the composite to separate the acid gas from the acid gas absorbent. ### Claim 12 (depends on 11) An acid gas removal apparatus comprising: an acid gas absorbent, an absorber that brings a subject gas mixture containing an acid gas into contact with the acid gas absorbent to make the acid gas absorbent absorb the acid gas and thereby to remove the acid gas from the subject gas mixture, and the regenerator according to claim 11, wherein the acid gas absorbent regenerated by the regenerator is reused in the absorber. ### Claim 13 A method of acid gas removal, comprising: an acid gas absorption step in which a subject gas mixture containing an acid gas is brought into contact with an acid gas absorbent to make the acid gas absorbent absorb the acid gas and thereby to remove the acid gas from the subject gas mixture, and an acid gas separation step in which the acid gas absorbent that has absorbed the acid gas is regenerated by allowing the acid gas absorbent to release the acid gas, wherein the regenerated acid gas absorbent is reused in the acid gas absorption step, and wherein, in the acid gas separation step, the acid gas absorbent that has absorbed the acid gas is brought into contact with a composite comprising an inorganic layered compound and an aluminum-containing oxide to regenerate the acid gas absorbent. ### Claim 14 (depends on 13) The method according to claim 13, wherein the acid gas absorbent is brought into contact with the composite under a temperature condition of less than 100° C. in the acid gas removal step.