Dynamic Simulation of Post-Combustion Capture System

Abstract

Post-combustion capture, as one of candidate technologies for carbon dioxide emission mitigation, has been employed in the chemical industry to separate CO2 from a gas mixture. However, the largest CO2 emission industry in China is the power industry, where CO2 is mainly released from coal-fired power plants. The study on the dynamic simulation of post-combustion capture system is indispensable for the future implementation of post-combustion capture system on coal-fired power plants, because the output of each coal-fired power plant is controlled by the grid and varies with time in China. Using DYNSIM software, we built a dynamic model for the typical post-combustion capture system, i.e. CO2 absorption/desorption process using aqueous MEA solution. A set of case studies were carried out to investigate the performance of post-combustion capture system. The simulation results show that the flow rate of flue gas and the flow rate of lean solution can greatly influent the stability and the capture ratio of a post- combustion capture system. Therefore, some special control strategies should be designed for them in order to keep the capture system running steadily.