Analysis Of Energy Consumption Of CO₂Capture And Association Studies Of Coal-based Methanol/Power Poly-generation System

Since1990s, greenhouse gas emissions from the use of fossil fuels has caused global warm and a series of abnormal climatic phenomena. The greenhouse effect is forcing people to realize the importance of the earth’s climate to the survival and the development of human. The combustion of the coal, oil, natural gas and other fossil fuels produces80%CO2for the moment, in which about38%CO2comes from the combustion of coal. China is one of the major countries of coal production and consumption in the world. With the development of China’s economy and improvement of living standard, the consumption of coal may be kept at rapid growth. To solve the conflict between the coal utilization and the emission of CO2, we have to find the clean way to utilize coal. Integrated coal Gasification Combined Cycle (IGCC) is a very promising clean coal technology, and is an important way to solve our energy problems such as low efficiency and serious pollution. CO2capture and Storage (CCS) is widely regarded as one of the most effective technologies for CO2emission reduction. CCS technology combined with IGCC may provide an promising way to improve the efficiency of energy utilization and reduced CO2emission.In this paper, IGCC system adopting pre-combustion CO2capture is simulated based on Aspen Plus. By setting different parameters of the system, the efficiency of the system and energy consumption of CO2capture under the different CO2capture rate are investigated. When adjusting the conversion ratio of shift reaction with fixed CO2separation ratio of the CO2separation unit, energy consumption of capturing every unit of CO2will increase with the growth of the capture rate of CO2, and when the rate of CO2capturing greater than70%, energy consumption of capturing every unit of CO2will increase rapidly. When adjusting separation ratio of CO2under fixed conversion ratio of shift reaction, energy consumption of capturing every unit of CO2will reduce gradually, and when the rate of CO2capturing greater than70%, the downward trend will become very gentle.Coal-based polygeneration system with CO2capture is simulated based on Aspen Plus in this paper. And the thermodynamic performance of Coal-based polygeneration system with CO2capture is presented, and the efficiency of the system and energy consumption of capturing every unit of CO2is investigated. Through the analysis, it is found that the polygeneration system could capture CO2with zero energy penalty compared with reference systems.This paper investigated the thermodynamic performance and economic performance of coal-based polygeneration system with CO2capture. The relative energy saving ratio and the cost of unit energy are analyzed, and the relationship between the thermodynamic and economic performance of the system is revealed. By changing the parameters of the system, it is proved that the value of circulation ratio of the best thermodynamic performance do not correspond to the best economic performance. Through the analysis, when the circulation ratio of system is maintained at about2.17～5.0, the thermodynamic performance and economic performance of coal-based polygeneration system could achieve the optimized state.