Preferred Mode of Energy Use for Miscanthus and Its Benefit Evaluation

摘要

At present, we are facing many serious problems, such as the unreasonable primary energy structure, shortage of fossil energy, excessive energy consumption and deterioration of ecological environment in our country. In the process of seeking renewable clean alternative energy sources, Miscanthus emerges victoriously as it is a kind of ideal energy resource to solve the above problems. This paper analyses the feasibility of the anaerobic digestion mode of Miscanthus and its benefit assessment, comparing with the mode of direct combustion and gasification. For environment benefit analysis, we made a life cycle assessment (LCA) with an example of daily production of 1400 m~3 biological gas of the anaerobic digestion engineering. It takes 1 MJ heat for the final product. Compared with the direct combustion mode, the CO_2 emission reduction rate is 81.1%. According to the emissions weighted calculation for environment impact potential, the environment impact load for anaerobic digestion is annual -211.3 people equivalent. In comparison, that of direct combustion is annual 144.21 people equivalent. Moreover, the investment recovery period of this system is 5.88 years; it shows the economy that it is good. In conclusion, the energy utilization mode of Miscanthus anaerobic digestion is environmentally friendly. It has great resource value, economic, environmental and social benefits, so its development and utilization has broad prospects.