Abstract
Much attention is focused on biodiesel fuel (BDF) alternative to diesel oil to mitigate global warming and oil dependence. In Kyoto
city, BDF produced from waste food oil is utilized as fuel of refuse trucks and city buses. LCA method was applied to evaluate the
utilization system of BDF derived from waste food oil for Kyoto city bus through the lifecycle that covered discharge,
collection/transportation, plant construction, BDF production and usage in terms of CO2, NOx, SOx and energy consumption. We have
confirmed that usage stage was dominant and environmental load except NOx was reduced compared to diesel bus system. The largest
reduction rate was about 60% for SOx and an advantage of BDF over diesel fuel was demonstrated. Considering BDF burning as
carbon-neutral remarkably increased the reduction rate of CO2 for utilization system of industrial food waste oil. Lifecycle impact
assessment indicated that urban air pollution was the key contributor to environmental impact as external cost and the reduction of the
external cost due to global warming accounted for over 95% of the total reduction cost by introducing the BDF utilization system.
