天然气基车用替代燃料的节能减排分析

CNG和GTL是目前使用较多的两种天然气基车用替代燃料，这两种替代燃料在生产过程、运输方式、车辆使用效率等方面都存在着差别。为了客观评价两种替代燃料的能源消耗和环境影响，以城市公交客车为应用对象，采用生命周期评价的方法，分析了两种进口天然气基车用替代燃料（CNG和GTL）利用路径与传统柴油相比的石油节约和排放降低效果。结果表明，在生命周期范围内，GTL路径的石油能耗降低了99.4%，PM、CO、NO_x、SO_x、THC排放分别降低了33.9%、4.8%、7.3%、79.2%、20.9%，但CO₂排放升高了23.4%；CNG路径石油能耗降低了99%，CO₂、PM、NO_x和SO_x排放分别降低了8.5%、84.7%、26%、64.5%，但CO和THC排放分别升高了52.9%和197.9%。因此，天然气的利用可以大幅度降低石油燃料的消耗和污染物的排放量，其中CNG路径的综合节能减排效果优于目前的GTL技术路径。

Energy conservation and emission reduction of natural gas based alternative vehicle fuels

CNG and GTL are presently widely used natural gas based alternative vehicle fuels. These two fuels are different in terms of production, transportation and vehicle use efficiency. To objectively evaluate energy consumption and environment effect of the two fuels, based on city buses, oil saving and emission reduction effects of the application routes of the two kinds of imported natural gas (CNG and GTL) were analyzed and compared with that of traditional diesel by means of life cycle assessment method. The results showed that, within the full life cycle, GTL's application route can reduce oil consumption by 99.4%, and the amount of PM, CO, NOx, SOx and THC emission down by 33.9%, 4.8%, 7.3%, 79.2% and 20.9% respectively, whereas the CO2 emission up by 23.4%. CNG's application route can reduce oil consumption by 99%, and the amount of CO2, PM, NOx and SOx emission down by 8.5%, 84.7%, 26% and 64.5% respectively, while the amount of CO and THC emission up by 52.9% and 197.9%. Therefore, natural gas based alternative vehicle fuels could substantially reduce the petroleum consumption and pollution emission, of which CNG's comprehensive energy conservation and emission reduction effect is better than that of GTL.