Research On CO₂ Cryogenic Separation And Liquefaction Method Of The Coal-based Energy System

Recently, greenhouse gases (GHG) which is the cause of global warming is a problem of the international community.CO2 emissions of the electricity supply sector in China account for about half of the total volume in the country. Thus, reducing CO2 emissions in China's electricity supply sector will contribute significantly to the efforts of greenhouse gas (GHG) control in the country and the rest of the world.The study of CO2 reduction focuses on CCS internationally now. In our coal-based energy consumption structure, how to recycle CO2 from the coal-based energy systems with lower energy consumption is an important prerequisite for commercial operations of CCS in a large scale. Meanwhile, the development of clean energy is another method to solve the problem of CO2 emissions currently.In this paper, coal-based energy system as the object of the study, we have studied a variety of CO2 separation methods and analyzed the low-temperature CO2 separation technology. Furthermore, by the ASPEN, we have analyzed the phase change characteristics of the CO2 mixed gases at the low temperature. Based on the analysis of the cryogenic separation method, this paper puts forward a novel CO2 cryogenic separation and liquefaction integration method. By this method, most of CO2 can be separated from the mixed gases at a relatively higher condensing temperature through multi-stage cryogenic separation and compression. Moreover, by the distillation, this method can separate CO2 with low energy consumption, and make the CO2 purity in product reach 99.99%. This paper provides a new idea and approach to separate and compress CO2 from the mixed gases with higher CO2 concentration with low energy consumption.Furthermore, this paper undertakes a comprehensive analysis of CO2 mitigation costs, mitigation potential, and fossil energy conversation capacity of various carbon mitigation options, through which the carbon mitigation strategy of China's power industry is predicted and analyzed. The results reveal that, for China's power industry, the comprehensive utilization of various carbon mitigation options is an inevitable trend, and that energy saving, renewable energy and nuclear power are very important and should be given priority.