Review on the Use of Ionic Liquids (ILs) as Alternative Fluids for CO₂Capture and Natural Gas Sweetening

Abstract

The capture of CO2 from flue gases derived from fossil-fueled power plants and the absorption of CO2/H2S for natural gas sweetening purposes are two relevant industrial problems closely related to very important environmental, economical, and technological problems that need to be solved. Amine-based technologies are widely used in the industry for these purposes, but they lead to several problems that have led many researchers to pose new alternatives. Ionic liquids (ILs) have emerged in the last few years as promising new acid gas absorbents, and thus, this remarkable interest, in both industry and academia, has led to a large collection of experimental and theoretical studies in which the most important aspects of the absorption process are analyzed. In this review, we show the most relevant conclusions obtained from the analysis of the literature, analyzing the state-of-the-art results, trying to infer the viability of ILs as an alternative to the available amine-based absorption processes, and showing the possible future directions of research.