Study Of Life Cycle Energy Consumption, Environmental Emission And Economics Of Coal-Based Dimethyl Ehter As Vehicle Fuel

China is a country with abundant coal meanwhile a little natural gas and poor oil, and facing challenges in meeting the ever-growing energy demand from transportation while minimizing its adverse energy, environment and economic impacts. It is one of the key directions to make coal-based vehicle fuels in order to relieve oil shortage and realize the clean utilization of coal. Among many coal-based substitutes for conventional diesel, dimethyl ether (DME) has prominent characteristics. It can not only reduce harmful emissions, but also replace oil with coal indeed.In this dissertation, relative research and development of DME production, engine and vehicle fueled with DME are reviewed. Based on life cycle assessment (LCA) principle, a life cycle primary energy consumption and environmental emission analysis model of coal-based DME suitable for China is established. A DME urban bus is taken as functional unit and its fuel consumption and emission factors under urban transportation are achieved with a complex method of engine rig study and vehicle test cycle simulation. Then, the total life cycle primary energy consumption, VOC, CO, NOX, PM10, SO2 (criterion emissions) and greenhouse gases (GHGs) emissions of coal-based DME pathway are worked out. The impacts of electricity structure variation and GHGs reduction technologies are evaluated, and the influence of large scale application of coal-based DME on Chinese energy structure are also analyzed. Some comparisons of coal-based DME with conventional diesel and competitive coal-based diesel are carried out. Finally, the economic cost of coal-based DME is discussed.For DME bus as functional unit, a method of engine rig study combined with vehicle test cycle simulation is brought forward and applied to achieve its fuel consumption and emission factors. Compared with current diesel engine, the emissions of DME engine can work without any smoke in all running cases, and meet the requirements of Euroâ…¢regulation. Under urban transportation, the fuel consumption of DME bus is...