Process and engineering aspects of carbon capture by ionic liquids

The accumulation of greenhouse gases, leading to global warming necessitated the research for efficient and recyclable CO2 capture solvents. Ionic liquids (ILs) and IL-based solvents have paved the way for a new generation of highly efficient, economic, and eco-friendly CO2 capture solvents. This paper discusses the process of synthesizing different ILs and IL-based solvents, emphasizing the merits and demerits of different processes, followed by the characterization tools and techniques, and the important considerations in developing novel ILs. An extension of characterization is the screening process. Properties of synthesized ILs and IL-based solvents have been discussed in detail, along with properties of hybrid IL-based solvents. The highly tunable nature of ILs leads to a multitude of possible ILs and IL-based solvents that can be customized for specific requirements. The latter part of the paper describes various modelling and simulation techniques used to analyse and predict the CO2-IL interactions. In each section, the trends and technology used, are analysed and discussed, duly emphasizing the latest advances. The paper concludes with a discussion on the prospects and challenges in adopting ILs and IL-based solvents in CO2 capture.