CO₂ Capture by Ionic Liquids – An Answer to Anthropogenic CO₂ Emissions?

Abstract

Ionic liquids (ILs) are efficient solvents for the selective removal of CO₂ from flue gas. Conventional, offthe-shelf ILs are limited in use to physisorption, which restricts their absorption capacity. After adding a chemical functionality like amines or alcohols, absorption of CO₂ occurs mainly by chemisorption. This greatly enhances CO₂ absorption and makes ILs suitable for potential industrial applications. By carefully choosing the anion and the cation of the IL, equimolar absorption of CO₂ is possible. This paper reviews the current state of the art of CO₂ capture by ILs and presents the current research in this field performed at the ChemTech Institute of the Ecole d'Ingénieurs et d'Architectes de Fribourg.