CARBON DIOXIDE ABSORBING COMPOSITION INCLUDING ANTISOLVENT, AND METHOD AND APPARATUS FOR ABSORBING CARBON DIOXIDE USING THE SAME

• US 20150290581A1
• Filed: 10/18/2013
• Published: 10/15/2015
• Est. Priority Date: 11/09/2012
• Status: Abandoned Application

• Current Assignee: Korea Institute of Energy Research
• Original Assignee: Korea Institute of Energy Research
• Inventors: Jung, Taesung, Kim, Jong-Nam, Beum, Hee Tae, Han, Sang-Sup, Hong, Won Hi, Yoon, Hyung Cheol, Kim, Gyo Hee
• Application Number:
  US14/398,500
• Publication Number:
  US 20150290581A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2251/30 Alkali metal compounds
• CPC Class Codes: B01D 2251/302 of lithium
• CPC Class Codes: B01D 2251/304 of sodium
• CPC Class Codes: B01D 2251/306 of potassium
• CPC Class Codes: B01D 2251/606 Carbonates
• CPC Class Codes: B01D 2252/202 Alcohols or their derivatives
• CPC Class Codes: B01D 2252/2021 Methanol
• CPC Class Codes: B01D 2252/2023 Glycols, diols or their derivatives
• CPC Class Codes: B01D 2252/2025 Ethers or esters of alkylene glycols, e.g. ethylene or propylene carbonate
• CPC Class Codes: B01D 2252/2026 Polyethylene glycol, ethers or esters thereof, e.g. Selexol
• CPC Class Codes: B01D 2252/20468 containing a pyrrolidone-ring
• CPC Class Codes: B01D 2252/504 Mixtures of two or more absorbents
• CPC Class Codes: B01D 2252/602 Activators, promoting agents, catalytic agents or enzymes
• CPC Class Codes: B01D 2252/604 Stabilisers or agents inhibiting degradation
• CPC Class Codes: B01D 2252/606 Anticorrosion agents
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: B01J 20/04 : comprising compounds of alkali metals, alkaline earth metals or magnesium
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02C 20/40 : of CO2

Abstract

This invention relates to a carbon dioxide absorbing composition including an antisolvent, and to a method and apparatus for absorbing and regenerating carbon dioxide using the same, wherein in a process and apparatus for absorbing carbon dioxide from a gas mixture including carbon dioxide such as a flue gas of a coal-fired power plant and separating a bicarbonate slurry including a large amount of carbon dioxide so as to be regenerated at high pressure, a bicarbonate slurry production yield can be increased to thereby reduce the cost for sensible heat, latent heat and regeneration energy necessary for regeneration, cooling and heating of the carbon dioxide absorbing solution.

Claims

1. A carbon dioxide absorbing composition for use in a process including absorbing carbon dioxide from a gas mixture including carbon dioxide and separating a bicarbonate slurry including a large amount of carbon dioxide so as to be regenerated at a high pressure, comprising:

a carbon dioxide absorbing inorganic salt solution and an aqueous antisolvent wherein the aqueous antisolvent is a polar protic solvent.

2. The composition of claim 1, wherein the carbon dioxide absorbing inorganic salt solution is a solution of a monovalent inorganic salt including any one selected from the group consisting of sodium, potassium, lithium, rubidium and cesium.

3. The composition of claim 1, wherein the carbon dioxide absorbing inorganic salt solution is a potassium solution.

4. The composition of claim 1, wherein an inorganic salt concentration of the carbon dioxide absorbing inorganic salt solution is 30 wt % when using an inorganic salt including sodium, 50 wt % when using an inorganic salt including potassium, 2 wt % when using an inorganic salt including lithium, 30 wt % when using an inorganic salt including rubidium, or 70 wt % when using an inorganic salt including cesium.

5. The composition of claim 1, wherein the aqueous antisolvent is selected from the group consisting of methanol, ethanol, propanol, ethyleneglycol, propyleneglycol, diethyleneglycol, triethyleneglycol, polyethyleneglycol, N-methylpyrrolidone, propylenecarbonate, ethylenecarbonate and mixtures thereof.

6. The composition of claim 5, wherein the aqueous antisolvent is ethanol or N-methylpyrrolidone.

7. The composition of claim 5, wherein the aqueous antisolvent is contained in an amount of 30 wt % or less but exceeding zero based on a total weight of the carbon dioxide absorbing composition.

8. The composition of claim 1, further comprising any one or a mixture of two or more selected from the group consisting of an absorption rate enhancer, an antioxidant and a corrosion inhibitor.

9. A method of absorbing and regenerating carbon dioxide, comprising:

bringing the carbon dioxide absorbing composition of claim 1 into contact with a gas mixture including carbon dioxide to thus absorb carbon dioxide;

cooling the carbon dioxide absorbing composition having absorbed carbon dioxide, thus forming a bicarbonate slurry; and

separating a solid slurry and a liquid absorbing solution including an aqueous antisolvent from the bicarbonate slurry, and then separating and recovering the antisolvent from the absorbing solution while heating the solid slurry to a high temperature, thus separating carbon dioxide.

10. The method of claim 9, wherein bringing the carbon dioxide absorbing composition into contact with the gas mixture including carbon dioxide is performed by spraying the carbon dioxide absorbing composition to the gas mixture including carbon dioxide at 60˜

80°

C. and atmospheric pressure.

11. The method of claim 9, wherein the carbon dioxide absorbing composition having absorbed carbon dioxide is cooled to 10˜

50°

C., thus forming the bicarbonate slurry.

12. The method of claim 9, wherein the solid slurry separated from the bicarbonate slurry is heated at 100˜

250°

C. and 1˜

20 bar, thus separating carbon dioxide.

13. The method of claim 9, further comprising subjecting the liquid absorbing solution including the antisolvent separated from the bicarbonate slurry to liquid-liquid separation, thus separating the aqueous antisolvent.

14. An apparatus for absorbing and regenerating carbon dioxide, comprising:

an absorber 2 for selectively absorbing carbon dioxide from a flue gas using the carbon dioxide absorbing composition of claim 1;

a crystallizer 5 for cooling the carbon dioxide absorbing composition having absorbed carbon dioxide using a cooler or a heat exchanger to form a bicarbonate slurry;

a filter 8 for separating a solid slurry and a liquid absorbing solution including an aqueous antisolvent from the bicarbonate slurry; and

a regenerator 14 for heating the solid slurry to a high temperature to separate carbon dioxide.

15. The apparatus of claim 14, further comprising a liquid-liquid separator 10 for separating the aqueous antisolvent from the liquid absorbing solution including the antisolvent.

16. The apparatus of claim 14, wherein the regenerator 14 comprises a reboiler 15 for decomposing the solid slurry and a condenser 16 for separating water and carbon dioxide from each other.