CARBON DIOXIDE CAPTURE SYSTEM AND A METHOD OF OPERATING A CARBON DIOXIDE CAPTURE SYSTEM

• US 20170165603A1
• Filed: 11/02/2016
• Published: 06/15/2017
• Est. Priority Date: 12/14/2015
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: FUJITA, Koshito, Udatsu, Mitsuru
• Granted Patent: US 10,864,478 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2252/204 Amines
• CPC Class Codes: B01D 53/1406 Multiple stage absorption
• CPC Class Codes: B01D 53/1412 Controlling the absorption process
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/18 Absorbing units; Liquid distributors therefor B01D3/16, B01D3/26, B01D3/30 take precedence; packing elements B01J19/30, B01J19/32
• 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
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

A carbon dioxide capture system includes a first capture system and a second capture system. The first capture system including a first absorber that causes carbon dioxide contained in a combustion exhaust gas to be absorbed in a first absorbing liquid. The second capture system causes carbon dioxide contained in a combustion exhaust gas to be absorbed in a second absorbing liquid. The second rich liquid releases carbon dioxide at a lower temperature than the first rich liquid.

Claims

1. A carbon dioxide capture system comprising:

a first capture system including

a first absorber configured to cause carbon dioxide contained in a first combustion exhaust gas to be absorbed in a first absorbing liquid to produce a first rich liquid, and

a first stripper configured to cause the carbon dioxide to be released from the first rich liquid produced by the first absorber; and

a second capture system including

a second absorber configured to cause carbon dioxide contained in a second combustion exhaust gas to be absorbed in a second absorbing liquid to produce a second rich liquid, and

a second stripper configured to cause the carbon dioxide to be released from the second rich liquid produced by the second absorber,

wherein a temperature at which the second rich liquid releases carbon dioxide is lower than a temperature at which the first rich liquid releases carbon dioxide.

2. The carbon dioxide capture system according to claim 1, further comprising:

a first reboiler that heats the first absorbing liquid by a first heating medium and discharging the first heating medium as a first discharged heating medium; and

a second reboiler that heats the second absorbing liquid by the first discharged heating medium discharged from the first reboiler.

3. The carbon dioxide capture system according to claim 2, further comprising:

a plurality of the first capture systems arranged in parallel, and the first discharged heating medium discharged from the first reboiler of at least one of the plurality of the first capture systems is supplied to the second reboiler.

4. The carbon dioxide capture system according to claim 2, further comprising:

a flashing device that flashes the first discharged heating medium discharged from the first reboiler and supplied to the second reboiler.

5. The carbon dioxide capture system according to claim 2,

wherein the second reboiler heats the second absorbing liquid by the first discharged heating medium, and

the carbon dioxide capture system further comprises:

a third reboiler that heats the first discharged heating medium that heats the second reboiler.

6. The carbon dioxide capture system according to claim 1,

wherein the pressure in the first absorber is higher than the pressure in the second absorber.

7. The carbon dioxide capture system according to claim 2, wherein:

the first absorber discharges a carbon dioxide-containing gas from the first absorbing liquid; and

the second capture system further includes a fourth reboiler that heats the second absorbing liquid by the carbon dioxide-containing gas discharged from the first absorber.

8. The carbon dioxide capture system according to claim 2, wherein the second capture system further comprises:

a fifth reboiler that heats the second absorbing liquid by the first absorbing liquid discharged from the first absorber.

9. The carbon dioxide capture system according to claim 2, wherein the first capture system further comprises:

a first heat exchanger in which the first absorbing liquid supplied from the first stripper is heated by the first absorbing liquid supplied from the first absorber; and

a heater that heats the first absorbing liquid supplied to the first stripper from the first heat exchanger.

10. The carbon dioxide capture system according to claim 2, wherein the second capture system further comprises:

a fifth reboiler that heats the second absorbing liquid by the first absorbing liquid discharged from the first stripper; and

the first capture system further includes

a heater that heats the first absorbing liquid supplied to the first stripper from the first heat exchanger, and

a first reboiler that heats the first absorbing liquid in the first stripper by a first heating medium.

11. The carbon dioxide capture system according to claim 2, wherein:

the first capture system further includes a first cooler that cools the first absorbing liquid supplied to the first absorber from the first stripper by a second discharged cooling medium; and

the second capture system further includes a second cooler that cools the second absorbing liquid supplied to the second absorber from the second stripper by a second cooling medium, and the second discharged cooling medium is discharged from the second cooler.

12. The carbon dioxide capture system according to claim 2, further comprising:

a flow control device that controls a first flow amount of the first combustion exhaust gas and a second flow amount of the second combustion exhaust gas; and

a controller that controls the first flow amount and the second flow amount to minimize a heat amount supplied to the first reboiler and the second reboiler.

13. A method of operating a carbon dioxide capture system comprising:

absorbing, in a first absorbing liquid, carbon dioxide contained in a first combustion exhaust gas to produce a first rich liquid;

stripping the carbon dioxide from the first rich liquid;

absorbing, in a second absorbing liquid, carbon dioxide contained in a second combustion exhaust gas to produce a second rich liquid; and

stripping the carbon dioxide from the second rich liquid,

wherein a temperature at which the second rich liquid releases carbon dioxide is lower than a temperature at which the first rich liquid releases carbon dioxide.