生命周期方法在天然气基汽车燃料评价中的运用

A application of LCA to four natural gas based automotive fuels

运用生命周期评价方法,对以天然气为原料生产压缩天然气、甲醇、二甲醚、柴油4种汽车代用燃料系统进行生命周期的能源、环境和经济评价.评价结果是:压缩天然气系统生命周期内的能耗相对少,总成本相对低,对生态环境更友好,压缩天然气是富含天然气地区一段时期内汽车代用燃料的优先选择.

The objective of this study is to carry out an economic, environmental and energy (EEE)life cycle study on natural gas based automotive fuels with conventional gasoline in abundant region of China; A set of indexes of four fuels/vehicles systems based on life cycle are assessed in term of impact of EEE, which natural gas produces compressed natural gas(CNG), methanol, Di-methyl Ether(DME) and Fischer-Tropsch Diesel(FTD). The study included fuel production, vehicle production, vehicle operation, infrastructure, and the end of vehicle life as a system for each fuel/vehicle system. A generic gasoline fueled car is used as a baseline. Data have been reviewed and modified based on the best knowledge available to local sources of Chongqing. The NG based methanol doesn't have a strong compositeness economically. However, it has potential to be a strong alternative when its price decreases and gasoline price increase. The NG and methanol-fueled vehicles are more environmentally friendly, in terms of most criteria pollutant emissions than the gasoline vehicle, except NO_x. The increase in NO_x emissions was emitted by coal burning for electricity. The NG and methanol-fueled vehicles produce less or the same level of greenhouse gas emissions as gasoline. The NG and methanol-fueled vehicles are less energy efficient than gasoline on a life cycle basis, mainly due to the energy consumed during the fuel production. The results indicate that direct use of CNG in a dedicated or bi-fuel vehicle is an economical choice for abundant region in China, which is also the most energy efficient and more friendly environmental. The study can be used to support decisions on how natural gas resources can best be utilized as a fuel/energy resource for automobiles, and what issues need to be solved in Chongqing region. The models and approach for this study can be applied in other regions of China as long as all the assumptions are well defined and modified to find a substitute automotive energy and make a energy policy in a specific region.