Solubility phenomena related to CO 2 capture and storage

• Published in: Pure and Applied Chemistry
• Main Authors: De Visscher, Alex, Conejo, Maria S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Walter de Gruyter GmbH 2013
• Subjects: General Chemical Engineering; General Chemistry; Carbonic acid
• Online Access: http://dx.doi.org/10.1351/pac-con-12-10-10; https://www.degruyter.com/view/journals/pac/85/11/article-p2051.xml; https://www.degruyter.com/document/doi/10.1351/pac-con-12-10-10/xml; https://www.degruyter.com/document/doi/10.1351/pac-con-12-10-10/pdf

Capturing CO 2 emissions from energy production and storing it under the ground is a potential CO 2 mitigation strategy that currently receives much attention. Both CO 2 capture and CO 2 storage are solubility problems. This paper reviews some important solubility aspects of CO 2 capture and storage that are often overlooked. Until very recently, there was not a single CO 2 solubility relationship that was both applicable in a wide temperature range and thermodynamically consistent with the enthalpy of solution of CO 2 . Furthermore, very often the relationship used for the first acidity constant of carbonic acid as a function of temperature is inconsistent with the relationship used for the solubility constant (or Henry constant) of CO 2 . The removal of CO 2 from a gas stream with amine solutions is usually viewed as a chemical reaction, which leads to the practice of heating to remove the CO 2 from the solvent. However, viewing this process as a solubility phenomenon suggests the practice of using vacuum to remove the CO 2 from the solvent, a potentially more efficient approach.