Research On Evaluation Of Technology And Economy Of Biodiesel Based On Life Cycle Assessment

Life Cycle Assessment(LCA), objective of which is to elucidate the impact of biodiesel on energy supply and natural environment and its economic value while giving an assessment on commercialization application of biodiesel, is performed employing the most commonly accepted 3E evaluation model based on theory of LCA in this study. Two categories of biodiesel derived from palm oil and rapseed oil respectively are chosed to be the objects. Proceeding from analysis on life cycle process of these two biodiesel, LCA on energy consumption, green house gas emission and economical efficiency is carried out, detailed comparison is drawn while the value of biodiesel derived from vegetable oil is elucidated taking these two categories of biodiesel as illustrative example.Several conclusions can be obtained from this study. In terms of energy balance, net energy output is generated from both full life cycles of these two categories of biodiesel, energy ratio (ratio of output energy to input energy) is 3.53 and 1.44 respectively corresponding to biodiesel derived from palm oil and rap oil. Palm biodiesel's energy ratio is more than twice as high as that the rapseed biodiesel's is. This indicates that palm oil could function as a better source of biodiesel comparing with rap oil. In terms of green house gas emission, both these two categories of biodiesel are proved to be environmental friendly fuel comparing with diesel as the quantity of CO2 that is absorbed during their full life cycle is much larger than that is produced. With the contribution of biodiesel derived from vegetable oil made during the process of their full life cycle, green house emissions could be enormously reduced. However, in terms of production cost, the phenomenon that considerable portion of the total cost is occupied by the cost of raw material is observed in both assessment results of these two categories of biodiesel. Especially in the case of biodiesel derived from rap oil, the portion of raw material cost is larger than 89% while the portion of crew oil is larger than 87%. The improvement of economical efficiency in the commercialization application of both categories of biodiesel depend on the reduction of raw material cost.