(70h) Use of Reversible Ionic Liquids as Solvents for Post-Combustion Recovery of CO2 From Coal-Fired Power Plants

CO₂ emissions are likely to be regulated in the near future, so we need to develop energy and cost efficient strategies for CO₂ capture. Coal-fired power plants, essential for electricity generation, are one of the largest emitters of CO₂.  Our unique reversible ionic liquids (RevILs) take advantage of a dual chemical and physical absorption capture mechanism. Unlike traditional ionic liquids, these silylamine-based solvents react with CO₂, forming an ionic liquid that may further capture CO₂ through a physical absorption process. Through thermal reversion, the CO₂-swollen ionic liquids return to their molecular components, releasing chemically and physically absorbed CO₂.  The precursors thus recovered are then recycled for additional capture.  Reversible ionic liquids can effectively capture CO₂ without the requirement of large quantities of a co-solvent such as water, contrasting with the current monoethanolamine (MEA) technology used for CO₂ capture. This allows for significant energy savings during the regeneration step.  

We leverage an extensive understanding of structure-property relationships, and present the optimization of RevIL-based systems for CO₂ capture through viscosity, heats of generation and physical capacity. Further, we discuss the use of a unique in-situ technique to measure physical absorption, and hence values for Henry’s Law constants, as a guide for identifying molecules with optimal capture properties.