Abstract: A hybrid life cycle assessment model is built based on Chinese Economic Input-Output Life Cycle Assessment (EIO-LCA) Model 2007 and PLCA. The life cycle GHG emissions of cassava ethanol are calculated and its indirect emission is then allocated into 43 sectors. The results indicate that the life cycle GHG emission of cassava ethanol is 96.2 g/MJ, direct emission, indirect emission and carbon absorbed by photosynthesis is 130.2 g/MJ, 36.9 g/MJ and 70.9 g/MJ, respectively. The electric and heat power sector contributes the most emission in the indirect emission of cassava ethanol, accounts for 32.2%. Compared with traditional gasline, GHG emission reduction of cassava ethanol is not obvious. The hybrid method has the capacity to calculate the life cycle GHG emissions of cassava ethanol more comprehensively, and to reflect the distribution of indirect emission in the sectors of production chain, thus it can help improve policy making in emission reduction.

Key words: fuel ethanol, life cycle assessment, EIO-LCA, greenhouse gas emissions

摘要： 基于中国2007年EIO-LCA模型和PLCA构建了混合生命周期评价模型, 计算了木薯乙醇生命周期的温室气体排放量, 并将间接排放分解到43个行业部门。研究显示, 木薯乙醇生命周期温室气体净排放总量为96.2 g/MJ, 其中直接和间接排放量分别为130.2和36.9 g/MJ, 光合作用吸收CO₂ 70.9 g/MJ。间接排放中, 排放最多的部门是电力、热力的生产和供应业, 占间接排放总量的32.2%。另外, 相对于传统汽油, 木薯乙醇的减排效果并不明显。混合生命周期评价模型能更全面的计算燃料乙醇生命周期的温室气体排放量, 反映间接排放在生产链各部门的分布情况, 对相关减排政策的制定具有指导意义。

关键词: 燃料乙醇, 生命周期评价, EIO-LCA, 温室气体