Technical and Economic Assessments of Ionic Liquids for Pre-Combustion CO2 Capture at IGCC Power Plants

This study evaluates the feasibility and cost of ionic liquids (ILs) for precombustion carbon dioxide (CO2) capture at integrated gasification combined cycle power plants. The ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide is selected as a physical solvent for CO2 capture. Using newly developed performance and cost models, our analysis shows that the energy penalty of the IL-based capture system mainly arises from powering various compressors and solvent pumps, and compressors and absorbers are the dominant capital cost components. Using the Integrated Environmental Control Model (IECM) for power plant assessments, the cost of CO2 avoided by the IL-based capture system is estimated to be $62/t CO2 in constant 2011 USD. The preliminary comparisons of performance and cost between IL-and Selexol-based capture systems show that an IL-based capture system could be a viable alternative to current liquid solvent processes. (C) 2017 The Authors. Published by Elsevier Ltd.