Process for CO sub(2) Capture Using Ionic Liquid That Exhibits Phase Change

• Published in: Energy & fuels Vol. 28; no. 11; pp. 7070 - 7078
• Main Authors: Eisinger, Ronald S, Keller, George E
• Format: Journal Article
• Language: English
• Published: 20.11.2014
• Subjects: Absorption; Carbon capture and storage; Carbon dioxide; Electric power generation; Flue gases; Ionic liquids; Phase transformations; Power consumption
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef501546e

A novel process for capturing carbon dioxide from the flue gas of a coal-fired power plant has been shown to reduce parasitic power consumption substantially. The process employs an ionic liquid created at the University of Notre Dame that has a high capacity for absorbing CO sub(2) by chemical reaction. A distinguishing property of this ionic liquid is that it changes phase from solid to liquid upon reaction with CO sub(2). The process uses heat generated by this phase transition to lower parasitic power consumption. The driving force for CO sub(2) separation is a combination of temperature and pressure differences; the process could even work without the addition of heat. A realistic process was created to capture CO sub(2) efficiently. Computer simulation of the process enabled calculation of viable process conditions and power usage. The main concepts of the process were shown to work using a lab-scale apparatus. Parasitic power consumes 23% of net power generation, 55% lower than that of the monoethanolamine (MEA) process. However, capital cost is higher. The cost of electricity (COE) is 28% lower than that of the MEA process.