Potential and life cycle assessment of biodiesel production in China

Potential biodiesel production was evaluated by assuming that waste and cutover forestlands and burnt site areas, equivalent to 5.94% of China's land area, were used to cultivate the most suitable energy crop in each province of China. Jatropha, Xanthoceras, Pistacia, and Swida were the candidate energy crops in that order of priority based on yield and oil content. The crop was assigned by comparing crop climatic requirements and the meteorological statistics of each province and choosing the best match. Potential production for all of China was estimated to be 57.6 x 10(6) tons/yr on the basis of seed yields and biodiesel conversion factors. A logistics scenario was created for the transportation of crops and biodiesel, and a life cycle analysis of greenhouse gas (GHG) emissions and costs were evaluated for the cultivation, refinement, and transportation stages using local data on energy sources and costs. The production of biodiesel with and without waste biomass utilization creates emissions of 0.95 and 1.31 t CO2eq/t biodiesel, respectively, as compared to 2.08 t CO2eq/t fossil diesel. Fertilizer use in the cultivation stage accounts for 61% and 44% of GHG emissions with and without waste biomass utilization, respectively. The use of waste biomass and proper use of fertilizers are essential in reducing GHG emissions and enhancing the advantages of using biodiesel. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3449298]