Process of Ionic Liquids as Solvents

A typical CO₂ absorption process consists of a feed gas, an absorption column, a stripper column, and output streams of CO₂-rich gas to be sequestered, and CO₂-poor gas to be released to the atmosphere. Ionic liquids could follow a similar process to amine gas treating, where the CO₂ is regenerated in the stripper using higher temperature. However, ionic liquids can also be stripped using pressure swings or inert gases, reducing the process energy requirement.^[3] A current issue with ionic liquids for carbon capture is that they have a lower working capacity than amines. Task-specific ionic liquids that employ chemisorption and physisorption are being developed in an attempt to increase the working capacity. 1-butyl-3-propylamineimidazolium tetrafluoroborate is one example of a TSIL.^[2]