Post-combustion carbon dioxide (CO2) capture involves removing the diluted CO2 from flue gases after combustion of fossil fuels. It can be either retrofitted into existing plants (without significant modifications to the original plant) or built as end-of-pipe capture technology for new plant.
There are several post-combustion methods that can be used to capture CO2. The most common method involves passing the lean CO2-laden flue gas through a solvent in an absorption column, followed by desorption or stripping column. In the latter, a change in temperature and/or pressure will then release the CO2. Another process in development is calcium cycle capture where lime is used to capture CO2 to produce limestone, which can then be heated to drive off the CO2. All of these processes require additional energy input in order to drive off the CO2 from the liquid solvent or the solid sorbent; hence, the post-combustion CO2 capture is currently considered to be an energy intensive process.
The energy penalty associated with the stripping of CO2 is one of the main technology challenges that must be overcome in order to allow large-scale deployment of the post-combustion CO2 capture technology in power plants. There are a few instances of this technology being applied in chemical industries; however, its application in the coal-fired power sector has yet to be proven. Major considerations include the types of solvents used in the process and the handling of the waste by-products. The price and quality of the solvents also play a significant role in improving the overall efficiency and economics of the capture process.
CanmetENERGY is actively involved in the research and development (R&D) and demonstration of CO2 capture and pollution control technologies for fossil fuel combustion systems. We are currently working with our industrial and academic partners to develop novel post-combustion capture processes for integration with advanced clean coal power plants. The overall goal of this research is to reduce the cost and energy penalty associated with the existing post-combustion capture technologies and overcome the technical challenges facing the large scale deployment of these integrated systems for the capture and storage of CO2.