CO sub(2) capture by antisublimation process and its technical economic analysis

CO sub(2) capture by antisublimation consists in cooling the flue gases down to the freezing temperature of CO sub(2) and frosting CO sub(2) on a low temperature heat exchanger surface at a temperature range defined by the CO sub(2) concentration in the flue gases and the CO sub(2) capture efficiency. CO sub(2) is then defrosted and recovered in a liquid state. This CO sub(2) capture process by antisublimation is called AnSU registered . The CO sub(2) frosting temperature in flue gases is much lower than the triple point of water and therefore before CO sub(2) capture, water contained in flue gases is removed to reach high purity CO sub(2). This paper presents an overview of the antisublimation process and a brief review of test benches that have been set up in laboratory and on industry sites for validation and optimization of the antisublimation process dating back to the first one constructed in 2003. Energy consumption and cost penalty of CO sub(2) capture by antisublimation are evaluated for a coal-fired power plant. A technical and economic analysis has been made and compared to CO sub(2) capture by oxycombustion for a cement plant. Those two processes can be seen as cryogenics options and the detailed comparison gives insight into where energy losses take place and which capture process could be most adapted depending on specifications of the cement industry. [copy 2012 Society of Chemical Industry and John Wiley & Sons, Ltd