Carbon dioxide capture system and carbon dioxide capture method

Abstract

To provide a carbon dioxide recovery system and a carbon dioxide recovery method that can reduce decrease in moisture in absorption liquid, even in the case that the absorption liquid is used to absorb carbon dioxide in the air.SOLUTION: A carbon dioxide recovery system 1 includes: a cooling section which cools non-evaporated water remaining out of water, after water and air have been in direct contact with each other and some of the water has evaporated so that moisture vapor is produced; at least one absorption section in which carbon dioxide contained in the air is absorbed in absorption liquid, and moisture in moisture vapor is fed to the absorption liquid, according to gas-liquid contact of water and moisture vapor, and the absorption liquid containing an alkaline aqueous solution; and at least one regeneration section which diffuses the carbon dioxide absorbed in the absorption liquid.SELECTED DRAWING: Figure 1

Claims

1. A cooling unit in which water and air come into direct contact, and a portion of the water vaporizes to generate water vapor, thereby cooling the water that remains without vaporizing. At least one absorbent section in which, through gas-liquid contact between the air and the water vapor and an absorbent liquid containing an alkaline aqueous solution, carbon dioxide contained in the air is absorbed by the absorbent liquid and moisture from the water vapor is supplied to the absorbent liquid, The system includes at least one regeneration unit that releases carbon dioxide absorbed by the absorbent liquid, A carbon dioxide capture system equipped with this feature.

2. The carbon dioxide recovery system according to claim 1, wherein the cooling section is an open-type cooling tower.

3. The carbon dioxide recovery system according to claim 1 or 2, wherein the alkaline aqueous solution is an amine aqueous solution.

4. The at least one absorbent section includes a container having a shape that is longer horizontally than vertically, a gas-liquid contact section disposed within the container and containing a filler, and a liquid supply system that supplies the absorbent liquid to the filler. The carbon dioxide recovery system according to claim 1 or 2, wherein the container has a gas inlet provided at one end in the horizontal direction through which air supplied from the cooling unit is introduced, and a gas outlet provided at the other end in the horizontal direction through which the remaining air from which carbon dioxide has been removed at the gas-liquid contact section is discharged.

5. The at least one absorption unit includes an absorption liquid level gauge for measuring the liquid level of the absorption liquid that has absorbed carbon dioxide. The carbon dioxide recovery system according to claim 1 or 2, wherein the amount of air supplied from the cooling unit to the at least one absorption unit is controlled based on the liquid level measured by the absorption liquid level gauge.

6. The at least one absorption section includes a gas-liquid contact section and a pre-treatment section provided on the cooling section side of the gas-liquid contact section, In the gas-liquid contact area, the gas-liquid contact between the air and water vapor and the absorbent liquid is performed. The carbon dioxide recovery system according to claim 1 or 2, wherein the pre-treatment unit sprays pre-treated water onto the air supplied from the cooling unit.

7. The pre-treatment unit includes a pre-treatment water level meter for measuring the liquid level of the pre-treatment water. The carbon dioxide recovery system according to claim 6, wherein the amount of air supplied from the cooling unit to the pre-treatment unit is controlled based on the liquid level measured by the pre-treatment water level gauge.

8. The at least one absorbing section is a plurality of absorbing sections arranged in parallel on the airflow path, The carbon dioxide recovery system according to claim 1 or 2, wherein the number of the plurality of absorption units is greater than the number of the at least one regeneration unit.

9. A process in which water and air come into direct contact, and a portion of the water vaporizes to generate water vapor, thereby cooling the water that remains without vaporizing. The process involves gas-liquid contact between the air and the water vapor and an absorbent liquid containing an alkaline aqueous solution, thereby absorbing carbon dioxide contained in the air and supplying moisture from the water vapor to the absorbent liquid. A step of releasing the carbon dioxide absorbed by the absorbent liquid, A method for capturing carbon dioxide, including [specific carbon dioxide capture methods].

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