System Coupling Of CO₂Capture With Low Energy Consumption For Existing Power Units

As global warming becomes increasingly serious, extensive attention has been paid on realizing greenhouse gas (represented by CO2) emission control. China is one of the largest CO2emitter in the world, it is reported that China’s power generation industry (mainly refers to the existing power plants whose total capacity reaches800billion KWh) contributes to almost half of the total CO2emission. Hence realizing CO2reduction in China’s power generation industry is of great importance to mitigate world-wide global warming.Currently several progress are made as domestic and abroad researchers devoted to studying CO2capture via chemical abroption from different aspects. However, system integration and techno-economic analysis on large-scale CO2capture which thoroughly consider the characteristics of existing power plants in China are still very rare.Based on existed CO2capture methods, this paper focus on analyzing the CO2capture procedure and model of existing power plants, then reveals the fact that extracting point restraint is inevitable in actual power plants which achieves CO2capture via chemical absorption method. On this basis, this study puts forward a system coupling scheme which is mainly made up of pressure integration, heat integration and low-pressure cylinder flow optimization, here Aspen Plus is applied to simulate and analyze the thermal, techno-economic performances of the proposed scheme. Furthermore, considering the difference in CO2capture process between new coal-fired power plants and existing power plants, this paper proposes a novel CO2capture integration system based on single cylinder back pressure turbine, which significantly improves power generation efficiency with CO2captured, the proposed system can serve as a new approach to designing the CO2capture process of new power plants.Besides the chemical absorption method mentioned above, this study takes full advantage of another CO2reduction method-improving energy utilization rate, with problems such as combustion instability and low combustion efficiency under low-load operation condition fully considered, two kinds of combustor which burn inferior coal are elaborated.