# US 2025/0144559 A1 · Apparatus and process for capturing carbon dioxide in flue gas

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- Number: US 2025/0144559 A1
- Document ID: US20250144559A1
- Status: Published application
- Kind: A1
- Application number: 18/551,351
- Filed: 2023-07-25
- Published: 2025-05-08
- Earliest claimed: 2022-07-25
- Assignees: Airrane Co., Ltd.
- Applicants: Airrane Co., Ltd.
- Inventors: Seong Yong HA; Sun Keun LEE; Kwang Joon MIN; Chung Seop LEE; Jin Hyuk YIM; Sang Hoon HAN; Chae Sung LIM; Jae Hoon SHIM
- Web page: https://patentgrep.com/patent/US20250144559A1

## CPC

- B01D 53/229: {Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)}
- F25J 3/0266: {separation of carbon dioxide (production of carbon dioxide in general C01B32/00)}
- B01D 53/002: {by condensation}
- B01D 53/22: by diffusion (manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00)
- B01D 53/226: {in serial connexion}
- B01D 53/62: Carbon oxides
- B01D 71/68: Polysulfones; Polyethersulfones
- C01B 32/55: Solidifying
- B01D 2257/504: Carbon dioxide
- B01D 2258/025: from metallurgy plants
- B01D 2258/0283: Flue gases
- F25J 2200/02: in a single pressure main column system
- F25J 2200/70: Refluxing the column with a condensed part of the feed stream, i.e. fractionator top is stripped or self-rectified
- F25J 2205/20: using solidification of components
- F25J 2205/40: using hybrid system, i.e. combining cryogenic and non-cryogenic separation techniques
- F25J 2205/80: using membrane, i.e. including a permeation step
- F25J 2210/04: Mixing or blending of fluids with the feed stream
- F25J 2210/70: Flue or combustion exhaust gas
- F25J 2215/04: Recovery of liquid products
- F25J 2220/82: Separating low boiling, i.e. more volatile components, e.g. He, H2, CO, Air gases, CH4
- F25J 2230/30: Compression of the feed stream
- F25J 2245/02: Recycle of a stream in general, e.g. a by-pass stream
- F25J 2270/90: External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
- 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)
- F25J: LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS {OR LIQUEFIED GASEOUS} MIXTURES BY PRESSURE AND COLD TREATMENT {OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE (cryogenic pumps F04B37/08; gas storage vessels, gas holders F17; filing vessels with, or discharging from vessels, compressed, liquefied or solidified gases F17C; refrigeration machines, plants, or systems F25B)}
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]

## Abstract

The present disclosure relates to a process and apparatus for capturing carbon dioxide in flue gas, and the present disclosure performs a carbon dioxide recovery separation membrane process using cold heat in a carbon dioxide liquefaction process through a separation tower, thereby reducing energy consumption and remarkably improving separation efficiency.

## Claims

### Claim 1

An apparatus for capturing carbon dioxide in flue gas, comprising:
a first compressor configured to compress a first compressor feed gas including flue gas;
a first capture separation membrane configured to separate a first capture separation membrane feed gas including the gas compressed by the first compressor into a first capture separation membrane permeate gas and a first capture separation membrane residual gas;
a second compressor configured to compress a second compressor feed gas including the first capture separation membrane permeate gas;
a liquefaction heat exchanger configured to cool down the gas compressed by the second compressor;
a separation tower configured to separate the gas cooled by the liquefaction heat exchanger into a high purity carbon dioxide liquid and a carbon dioxide containing gas; and
a first recovery separation membrane configured to separate the carbon dioxide containing gas into a first recovery separation membrane permeate gas and a first recovery separation membrane residual gas, and circulate the first recovery separation membrane permeate gas to the first compressor, the first capture separation membrane or the second compressor.

### Claim 2 (depends on 1)

The apparatus for capturing carbon dioxide in flue gas according to claim 1, further comprising:
a second capture separation membrane configured to separate a second capture separation membrane feed gas including the first capture separation membrane permeate gas into a second capture separation membrane permeate gas and a second capture separation membrane residual gas,
wherein only the second capture separation membrane permeate gas in the first capture separation membrane permeate gas is compressed by the second compressor.

### Claim 3 (depends on 1)

The apparatus for capturing carbon dioxide in flue gas according to claim 1,
wherein a temperature of the gas fed into the first recovery separation membrane is −40 to 0° C.

### Claim 4 (depends on 1)

The apparatus for capturing carbon dioxide in flue gas according to claim 1,
wherein the first recovery separation membrane is made of at least one of polysulfone (PSF) or polyimide (PI).

### Claim 5 (depends on 1)

The apparatus for capturing carbon dioxide in flue gas according to claim 1, further comprising, before feeding the gas compressed by the first compressor into the first capture separation membrane,
a first heat exchanger network configured to cool down by heat exchange with at least one of the first capture separation membrane permeate gas, the first capture separation membrane residual gas, the carbon dioxide containing gas, the first recovery separation membrane permeate gas or the first recovery separation membrane residual gas.

### Claim 6 (depends on 2)

The apparatus for capturing carbon dioxide in flue gas according to claim 2, further comprising, before feeding at least one capture separation membrane feed gas of the gas compressed by the first compressor or the first capture separation membrane permeate gas into the separation membrane,
a heat exchanger network configured to cool down by heat exchange with at least one of the first capture separation membrane permeate gas, the first capture separation membrane residual gas, the second capture separation membrane permeate gas, the second capture separation membrane residual gas, the carbon dioxide containing gas, the first recovery separation membrane permeate gas or the first recovery separation membrane residual gas.

### Claim 7 (depends on 2)

The apparatus for capturing carbon dioxide in flue gas according to claim 2, further comprising:
a #2-1 capture separation membrane configured to separate the second capture separation membrane residual gas into a #2-1 capture separation membrane permeate gas and a #2-1 capture separation membrane residual gas;
a #2-2 heat exchanger configured to exchange heat between the first capture separation membrane permeate gas and the first recovery separation membrane permeate gas;
a #2-3 heat exchanger configured to exchange heat between the first capture separation membrane permeate gas cooled by the #2-2 heat exchanger and the #2-1 capture separation membrane permeate gas;
a #2-4 heat exchanger configured to exchange heat between the first capture separation membrane permeate gas cooled by the #2-3 heat exchanger and at least one of the #2-1 capture separation membrane residual gas or the first recovery separation membrane residual gas;
a #2-5 heat exchanger configured to exchange heat between the first capture separation membrane permeate gas cooled by the #2-4 heat exchanger and the second capture separation membrane permeate gas; and
a #2-6 heat exchanger configured to exchange heat between the first capture separation membrane permeate gas cooled by the #2-5 heat exchanger and the carbon dioxide containing gas,
wherein the #2-1 capture separation membrane permeate gas is circulated to the first compressor, the first capture separation membrane or the second capture separation membrane.

### Claim 8 (depends on 1)

The apparatus for capturing carbon dioxide in flue gas according to claim 1, further comprising:
a dry ice production unit including a chamber in which the high purity carbon dioxide liquid is received and converted to dry ice and an outlet through which a residual carbon dioxide gas not having been converted to the dry ice exits.

### Claim 9 (depends on 8)

The apparatus for capturing carbon dioxide in flue gas according to claim 8, wherein the residual carbon dioxide gas is circulated to the first capture separation membrane.

### Claim 10 (depends on 8)

The apparatus for capturing carbon dioxide in flue gas according to claim 8, further comprising:
a second capture separation membrane configured to separate a second capture separation membrane feed gas including the first capture separation membrane permeate gas into a second capture separation membrane permeate gas and a second capture separation membrane residual gas;
a #2-1 capture separation membrane configured to separate the second capture separation membrane residual gas into a #2-1 capture separation membrane permeate gas and a #2-1 capture separation membrane residual gas;
a first heat exchanger network including a #1-1 heat exchanger configured to exchange heat between the gas compressed by the first compressor and the #2-1 capture separation membrane permeate gas; a #1-2 heat exchanger configured to exchange heat between the gas compressed by the first compressor and cooled by the #1-1 heat exchanger and the first capture separation membrane permeate gas; and a #1-3 heat exchanger configured to exchange heat between the gas compressed by the first compressor and cooled by the #1-2 heat exchanger and a nitrogen dominated gas including at least one of the first capture separation membrane residual gas, the #2-1 capture separation membrane residual gas or the first recovery separation membrane residual gas; and
a second heat exchanger network including a #2-1 heat exchanger configured to exchange heat between the first capture separation membrane permeate gas and the second capture separation membrane permeate gas; and a #2-2 heat exchanger configured to exchange heat between the first capture separation membrane permeate gas cooled by the #2-1 heat exchanger and the gas heated by the #1-2 heat exchanger,
wherein only the second capture separation membrane permeate gas in the first capture separation membrane permeate gas is compressed by the second compressor, and
wherein the #2-1 capture separation membrane permeate gas is circulated to the first compressor, the first capture separation membrane or the second capture separation membrane.

### Claim 11

A process for capturing carbon dioxide in flue gas, comprising:
a first compression step of compressing, by a first compressor, a first compressor feed gas including flue gas;
a first capture step of feeding a first capture separation membrane feed gas including the gas compressed by the first compressor into a first capture separation membrane to separate into a first capture separation membrane permeate gas and a first capture separation membrane residual gas;
a second compression step of compressing, by a second compressor, a second compressor feed gas including the first capture separation membrane permeate gas;
a liquefaction step of cooling down, by a liquefaction heat exchanger, the gas compressed by the second compressor;
a separation and purification step of feeding the gas cooled by the liquefaction heat exchanger into a separation tower to separate into a carbon dioxide containing gas and a high purity carbon dioxide liquid; and
a first recovery step of feeding the carbon dioxide containing gas into a first recovery separation membrane to circulate a first recovery separation membrane permeate gas passing through the first recovery separation membrane to the first compressor, the first capture separation membrane or the second compressor.

### Claim 12 (depends on 11)

The process for capturing carbon dioxide in flue gas according to claim 11, further comprising:
a second capture step of feeding a second capture separation membrane feed gas including the first capture separation membrane permeate gas into a second capture separation membrane to separate into a second capture separation membrane permeate gas and a second capture separation membrane residual gas,
wherein the second compression step comprises compressing, by the second compressor, only the second capture separation membrane permeate gas in the first capture separation membrane permeate gas.

### Claim 13 (depends on 11)

The process for capturing carbon dioxide in flue gas according to claim 11, wherein the first recovery separation membrane is made of at least one of polysulfone (PSF) or polyimide (PI).

### Claim 14 (depends on 11)

The process for capturing carbon dioxide in flue gas according to claim 11, further comprising:
a dry ice production step of converting the high purity carbon dioxide liquid to dry ice, and obtaining a residual carbon dioxide gas not having been converted to the dry ice.

### Claim 15 (depends on 11)

The process for capturing carbon dioxide in flue gas according to claim 11, further comprising, before feeding the gas compressed by the first compressor into the first capture separation membrane,
a heat exchange step of exchanging, by a heat exchanger network, heat with at least one of the first capture separation membrane permeate gas, the first capture separation membrane residual gas, the carbon dioxide containing gas, the first recovery separation membrane permeate gas or the first recovery separation membrane residual gas.