We can come to the conclusion : cost ratio of motor fuels and total lifecycle cost , after the life cycle assessment of automobile substitute fuels based on natural gas in chongqing . we can see the economic of each automobile substitute fuel . the suggestion of energy construction adjustment in chongqing can be conclude according these conclusions 最后文章讨论了生命周期评价在能源产品开发中的具体应用，通过对重庆地区汽车代用燃料的各生产环节成本及生命周期总成本的分析，讨论各种替代燃料的经济性及未来的经济前景，并根据分析结论对重庆地区能源结构调整提出了相应的建议。
The characteristics and the predominance of methanol used as the alternative fuel have been briefly presented , the study progress of all the methods of methanol used as fuel have been detailedly summarized , and the development prospect and the difficulties of methanol application have been shortly discussed 介绍了甲醇的特点及作为代用燃料的优势，详细综述了甲醇作为发动机燃料的各种燃用方式的研究进展，并对甲醇燃料在内燃机中的应用前景及存在的问题进行了探讨。
Through the analysis of the main used alternative fuel ' s emission performance , tries to find out the reason causing the different emission performance between several alternative fuel from fuel molecule structure and concludes the inner connections between fuel molecule structure and emission performance and can he served as a theory foundation for further study on now used alternative fuel and new developments of alternative fuel 摘要通过对现有的几种主流代用燃料排放特性的分析比较，从燃料的分子结构方面分析各种代用燃料排放特性差异的原因，进而推出燃料的分子结构与排放性能之间的内在规律性，为代用燃料的深入研究及开发提供一定的理论依据。
