Process integration and design for maximizing energy efficiency of a coal- fired power plant integrated with amine-based CO_2 capture process

摘要

System-wide integration of post-combustion CO2 capture process into a coal-fired power plant is an effective and practical strategy to improve cost-effectiveness for capturing CO2 emissions from the power sector. Considerable reduction of the net energy efficiency of a power plant by 20-40% is inevitable due to energy requirements for the CO2 capture and power requirement for the CO2 compression. Hence, this study focuses on minimizing the net efficiency penalty through integrated design of coal-fired power plant with CO2 capture process in a holistic and systematic manner. In order to analyze the techno-economic impact of integrated process on the net power plant efficiency, overall process models are developed in a commercial simulator Aspen Plus (R), in which a 550 MWnet, supercritical coal-fired power plant is simulated and validated. A pilot-scale post-combustion CO2 capture process based on MEA, together with CO2 compression, is modeled and scaled-up to meet the commercial-scale capacity. Simulation-assisted optimization is performed to enhance the overall performance of capture-integrated power generation through fully exploiting system interactions and examining relevant economic trade-offs. A case study is carried out to evaluate the effect of several heat integration options and demonstrate a considerable benefit for reducing the net efficiency penalty.