CO 2 recovery system and CO 2 absorption liquid

• US 8,568,520 B2
• Filed: 10/05/2010
• Issued: 10/29/2013
• Est. Priority Date: 10/07/2009
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ogawa, Takashi, Yamanaka, Susumu, Yamashita, Katsuya, Ohashi, Yukio
• Primary Examiner(s): Smith, Duane
• Assistant Examiner(s): SHAO, PHILLIP Y
• Application Number:
  US12/898,188
• Publication Number:
  US 20110079151A1
• Time in Patent Office: 1,120 Days
• Field of Search: None
• US Class Current: 96/234
• CPC Class Codes: B01D 2252/103 Water
• CPC Class Codes: B01D 2252/20405 Monoamines
• CPC Class Codes: B01D 2252/20484 with one hydroxyl group
• CPC Class Codes: B01D 2252/205 Other organic compounds not covered by B01D2252/00 - B01D2252/20494
• CPC Class Codes: B01D 2252/2053 Other nitrogen compounds
• CPC Class Codes: B01D 2252/502 having two or more functionalities in the same molecule other than alkanolamine
• CPC Class Codes: B01D 2252/504 Mixtures of two or more absorbents
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/1425 Regeneration of liquid absorbents
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

In an embodiment, a CO₂ recovery system has an absorber, a regenerator, and a circulation device. An absorption liquid has an aqueous solution of amine having an alcohol group, and dimethyl silicone oil in which a part of methyl groups is substituted by at least one type selected from an aminoalkyl group, a carboxyl group, and a hydroxyl-containing alkyl group. The absorber contacts a combustion exhaust gas of a fossil fuel and the absorption liquid to absorb CO₂, which is contained in the combustion exhaust gas, into the absorption liquid. The regenerator releases CO₂ by applying thermal energy to the CO₂-absorbed absorption liquid. A circulation device circulates the absorption liquid between the absorber and the regenerator.

Claims

1. A CO₂ recovery system, comprising:

an absorber for absorbing CO₂ contained in a combustion exhaust gas of a fossil fuel into an absorption liquid by contacting the combustion exhaust gas and the absorption liquid;

a regenerator for releasing CO₂ by applying thermal energy to the CO₂-absorbed absorption liquid; and

a circulation device for circulating the absorption liquid between the absorber and the regenerator,

wherein the absorption liquid has an aqueous solution of amine having an alcohol group and dimethyl silicone oil in which a part of a plurality of methyl groups is substituted by at least one type selected from an aminoalkyl group, a carboxyl group and a hydroxyl-containing alkyl group,

wherein a ratio of the dimethyl silicone oil to a total amount of water and the dimethyl silicone oil in the absorption liquid is from 10 mass % to 50 mass %.

2. The CO₂ recovery system according to claim 1, wherein the absorption liquid has:

first dimethyl silicone oil in which a part of methyl groups is substituted by a first substituent group selected from an aminoalkyl group, a carboxyl group, and a hydroxyl-containing alkyl group, and

second dimethyl silicone oil in which a part of methyl groups is substituted by a second substituent group selected from an aminoalkyl group, a carboxyl group and a hydroxyl-containing alkyl group and different from the first substituent group.

3. The CO₂ recovery system according to claim 1,

wherein the dimethyl silicone oil is dimethyl silicone oil in which a part of methyl groups is substituted by two or more types of substituent groups selected from an aminoalkyl group, a carboxyl group, and a hydroxyl-containing alkyl group.

4. The CO₂ recovery system according to claim 1,

wherein the amine is selected from an amine (A) having an alcohol group and a primary amino group, an amine (B) having an alcohol group and a secondary amino group, an amine (C) having an alcohol group and a tertiary amino group, and piperidines (D).

5. A CO₂ absorption liquid comprising:

an aqueous solution of amine having an alcohol group; and

dimethyl silicone oil in which a part of a plurality of methyl groups is substituted by at least one type selected from an aminoalkyl group, a carboxyl group, and a hydroxyl-containing alkyl group,

wherein a ratio of the dimethyl silicone oil to a total amount of water and the dimethyl silicone oil in the absorption liquid is from 10 mass % to 50 mass %.

6. The CO₂ absorption liquid according to claim 5,

wherein the absorption liquid has:

first dimethyl silicone oil in which a part of methyl groups is substituted by a first substituent group selected from an aminoalkyl group, a carboxyl group, and a hydroxyl-containing alkyl group, and

second dimethyl silicone oil in which a part of methyl groups is substituted by a second substituent group selected from an aminoalkyl group, a carboxyl group and a hydroxyl-containing alkyl group and different from the first substituent group.

7. The CO₂ absorption liquid according to claim 5 ,

wherein the dimethyl silicone oil is dimethyl silicone oil in which a part of methyl groups is substituted by two or more types of substituent groups selected from an aminoalkyl group, a carboxyl group, and a hydroxyl-containing alkyl group.

8. The CO₂ absorption liquid according to claim 5 ,

wherein the amine is selected from an amine (A) having an alcohol group and a primary amino group, an amine (B) having an alcohol group and a secondary amino group, an amine (C) having an alcohol group and a tertiary amino group, and piperidines (D).