# US 11,027,256 B2 · Amine-based carbon dioxide adsorbent resistant to oxygen and sulfur dioxide and method of preparing the same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,027,256 B2
- Document ID: US11027256B2
- Status: Granted
- Kind: B2
- Application number: 16/811,155
- Filed: 2020-03-06
- Published: 2020-07-02
- Granted: 2021-06-08
- Earliest claimed: 2017-11-15
- Assignees: Korea Advanced Institute of Science and Technology
- Applicants: Korea Advanced Institute of Science and Technology
- Inventors: Minkee Choi; Woosung Choi; Chaehoon Kim
- Web page: https://patentgrep.com/patent/US11027256B2

## CPC

- B01J 20/265: {modified or post-treated polymers (polymer carriers or substrates subjected to further impregnating or coating B01J20/3208)}
- B01D 53/02: by adsorption, e.g. preparative gas chromatography {(solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01)}
- B01D 53/0462: {Temperature swing adsorption}
- B01J 20/048: {containing phosphorus, e.g. phosphates, apatites, hydroxyapatites}
- B01J 20/103: {comprising silica}
- B01J 20/223: {containing metals, e.g. organo-metallic compounds, coordination complexes}
- B01J 20/28021: {Hollow particles, e.g. hollow spheres, microspheres or cenospheres}
- B01J 20/28071: {being less than 0.5 ml/g}
- B01J 20/28073: {being in the range 0.5-1.0 ml/g}
- B01J 20/28076: {being more than 1.0 ml/g}
- B01J 20/3204: {Inorganic carriers, supports or substrates}
- B01J 20/3236: {containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts}
- B01J 20/3265: {with an organic functional group containing a metal, e.g. a metal affinity ligand}
- B01J 20/328: {Polymers on the carrier being further modified}
- B01J 20/3289: {Coatings involving more than one layer of same or different nature}
- B01J 20/3293: {Coatings on a core, the core being particle or fiber shaped, e.g. encapsulated particles, coated fibers}
- B01D 2253/102: Carbon
- B01D 2253/106: Silica or silicates
- B01D 2253/108: Zeolites
- B01D 2253/202: Polymeric adsorbents
- B01D 2253/204: Metal organic frameworks (MOF's)
- B01D 2253/25: Coated, impregnated or composite adsorbents
- B01D 2253/311: Porosity, e.g. pore volume
- B01D 2257/302: Sulfur oxides
- B01D 2257/504: Carbon dioxide
- B01D 2258/0283: Flue gases
- Y02C 20/40: of CO2
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- 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

A core-shell type amine-based carbon dioxide adsorbent is described, including a chelating agent resistant to oxygen and sulfur dioxide, to inhibit oxidative decomposition of amine. As a core, a porous support is employed on which an amine compound is immobilized, and, as a shell, an amine layer resistant to inactivity by sulfur dioxide is utilized. Such adsorbent exhibits high oxidation resistance because the chelating agent functions to remove a variety of transition metal impurities catalytically acting on amine oxidation. In addition, the sulfur dioxide-resistant amine layer of the shell selectively adsorbs sulfur dioxide to protect the amine compound of the core and, at the same time, the amine compound of the core selectively adsorbs only carbon dioxide. Sulfur dioxide adsorbed on the shell is readily desorbable therefrom at about 110° C. and thus remarkably improved regeneration stability is obtained during temperature-swing adsorption (TSA) processes in which sulfur dioxide is present.

## Claims

### Claim 1

An amine-based carbon dioxide adsorbent having a core-shell structure comprising:
a core containing an amine compound and a porous support; and
a shell containing a sulfur dioxide-resistant amine compound and coated to surround the core,
wherein the shell is a tertiary amine-rich sulfur dioxide-resistant layer and a ratio of nitrogen present as tertiary amine with respect to nitrogen atoms present in the sulfur dioxide-resistant amine compound of the shell is 50% to 100%.

### Claim 2 (depends on 1)

The carbon dioxide adsorbent according to claim 1, wherein the sulfur dioxide-resistant amine compound of the shell comprises a hydroxyl group-containing carbon chain.

### Claim 3 (depends on 1)

The carbon dioxide adsorbent according to claim 1, wherein the sulfur dioxide-resistant amine compound of the shell is present in an amount of 0.1% by weight to 30% by weight, with respect to the total weight of the adsorbent.

### Claim 4 (depends on 1)

The carbon dioxide adsorbent according to claim 1, wherein the amine compound of the core comprises a unit skeletal structure represented by Formula 2 and Formula 3:
—[(CH2)x—NH2] [Formula 2]
wherein R is hydrogen or a branched chain, x is an integer of 2 to 6 and y is an integer of 1 to 100; and
—[(CH2)x—NH2] [Formula 3]
wherein R is hydrogen or a branched chain and xis an integer of 2 to 6.

### Claim 5 (depends on 1)

The carbon dioxide adsorbent according to claim 1, wherein the amine compound of the core is amino-silane selected from the group consisting of 3 aminopropyl-trimethoxysilane, trimethoxy(3-methylaminopropylsilane), N,N-dimethylaminopropyl trimethoxysilane and N-(3-trimethoxysilylpropyl)diethylenetriamine.

### Claim 6 (depends on 1)

The carbon dioxide adsorbent according to claim 1, wherein the amine compound of the core is present in an amount of 5 to 75% by weight, with respect to the total weight of the adsorbent.

### Claim 7 (depends on 1)

The carbon dioxide adsorbent according to claim 1, wherein the porous support is selected from the group consisting of silica, alumina, activated carbon and zeolite.

### Claim 8 (depends on 1)

The carbon dioxide adsorbent according to claim 1, wherein the porous support has a porosity of 0.1 to 5 cc/g.

### Claim 9 (depends on 1)

The carbon dioxide adsorbent according to claim 1, wherein the porous support is present in an amount of 25 to 95% by weight, with respect to the total weight of the adsorbent.

### Claim 10 (depends on 1)

A method of preparing the carbon dioxide adsorbent having a core-shell structure according to claim 1, comprising:
(a) immobilizing an amine compound on a porous support;
(b) adding a solution prepared by dissolving epoxide in a solvent to the amine compound immobilized on the support;
(c) forming a sulfur dioxide-resistant amine layer by reacting the amine compound immobilized on the support with epoxide; and
(d) obtaining a carbon dioxide adsorbent containing the sulfur dioxide-resistant amine layer by removing the solvent.

### Claim 11 (depends on 10)

The method according to claim 10, wherein a molar ratio of the nitrogen atom present in the amine compound immobilized on the support to epoxide is 1:0.2 to 1:1.

### Claim 12 (depends on 10)

The method according to claim 10, wherein the epoxide comprises at least one selected from the group consisting of 1,2-epoxyethane, 1,2-epoxypropane, 1,2-epoxybutene, 1,2-epoxypentane and 1,2-epoxyhexane.

### Claim 13 (depends on 1)

A method of adsorbing carbon dioxide using the adsorbent of claim 1, comprising contacting the adsorbent with a CO2-comprising gas.