| Recently, the greenhouse gas effect because of CO2emissionss becomes the worst global environmental problems for human beings. Electricity supply sector is the biggest producer of CO2emissions. Thus, reduction of CO2emissions in the electricity supply sector of China will make a significant contribution to our nation and even the whole world.The study of CO2reduction focuses on CCS internationally now. Further, the special attention has been historically focused on post-combustion technologies, which can be widely applicable to the scale of the fossil fuel power plant maturely. But it is restricted because of high energy consumption. Therefore, reducing energy consumption and improving energy efficiency are the key factors to reduce CO2emissions. In addition, the development of clean energy also is a new way to reduce CO2emissions.This paper presents the techno-economic performance of300MW、600MW coal-fired power plant with and without MEA-based CO2capture process through the Aspen Plus simulation, based on the operating data of the existing power plant. Then, economic factors are evaluated on the integration of CO2capture process with steam cycle. Furthermore, through the characteristics analysis of China’s enormous existing power plants, the paper puts forward several special system integration schemes for CO2capture in an existing600MW unit of China. Analysis is carried out in the performance of system integration with different stages. Finally, this paper also provides feasible technology solutions for decarburization retrofits of existing power plants. The results show that, when adopting CO2capture process, the cost for electricity is still tremendous but obviously better performance than before.Based on the thoroughly analysis of the thermal balance of CO2capture system and water-steam system, according to "temperature cascade, heat use" principle, the paper introduces an integrated system which contains a new coal-fired power plant, the CO2capture system and the heat supply system. The integrated system can decrease the influence which CO2capture system have on the power plants and increase the steam utilization ratio in an effective way by means of improving the water-steam flow path. At the same time, the system can make full use of the intermediate and low temperature waste heat through the integration of water-steam flow path, CO2capture flow path and terrestrial heat supply system. In addition, the paper also analyzes the performance on the change of exhaust steam pressure of the back pressure turbine and the different heat supply temperature in the integrated system. In a word, the new integrated system realizes the step-use of energy, showing the good thermodynamics performance when90%of CO2is captured. Thus, the realization of CO2emission on a large scale can come true with little energy consumption. The achievements will provide special technical ideas and approaches for the CO2emission reduction of heat and power cogeneration units.Furthermore, this study also analyzes some renewable energy sources, especially wind power generation characteristics, then put forward a Compressed Air Energy Storage(CAES) system. It will take an unstable wind energy into stable, high quality of electric power through the CAES. It is useful for wind power to the parallel operation and improves the utilization rate of renewable energy. On the one hand, it saves the existing fossil fuel. On the other hand, it also reduces the CO2emissions. Obviously, development of renewable energy sources is one of the most important development directions in future energy field. |
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