Currently, CO capture uses mostly amine-based absorption technologies, which are energy intensive and solvent intensive. Volatile organic compounds alone in chemical processes represent a multibillion-dollar industry. Therefore, ionic liquids offer an alternative that prove attractive should their other deficiencies be addressed.
During the capture process, the anion and cation play a crucial role in the dissolution of CO. Spectroscopic results suggest a favorable interaction between the anion and CO, wherein CO molecules preferentially attach to the anion. Furthermore, intermolecular forces, such as hydrogen bonds, van der Waals bonds, and electrostatic attraction, contributes to the solubility of CO in ionic liquids. This makes ionic liquids promising candidates for CO capture because the solubility of CO can be modeled accurately by the regular solubility theory (RST), which reduces operational costs in developing more sophisticated model to monitor the capture process.