Biodiesel Life Cycle Energy Demand
Table 5 and Figure 4 present the total primary energy demand used in each stage of the biodiesel life
cycle. One MJ of biodiesel requires an input of 1.2414 MJ of primary energy, resulting in a life cycle
energy efficiency of 80.55%. Biodiesel is comparable to petroleum diesel in the conversion of primary
energy to fuel product energy (80.55% versus 83.28%). The largest contribution to primary energy (87%)
is the soybean oil conversion step because this is where we have chosen to include the feedstock energy