Environmental footprint evaluation of Jatropha biodiesel production and utilization in Ethiopia: a comprehensive well-to-wheel life cycle analysis

In Ethiopia, a Life Cycle Analysis of Jatropha-based biodiesel was conducted using the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation model to assess energy consumption, efficiency, and greenhouse gas (GHG) emissions in the well-to-tank (WTT) and well-to-wheel stages. The inventory analysis involved field surveys and scenarios to evaluate energy savings, emission reductions, and air pollutants in biodiesel-diesel blends. In the WTT analysis, the energy consumption for producing 1 MJ of Jatropha-based biodiesel was found to be 0.43 MJ under rain-fed and 0.68 MJ under irrigated conditions. The net energy value was positive, and the net energy ratio was higher compared to that in other countries. The results show that GHG emissions at 19.8 g CO2 eq/MJ during the WTT stage can reduce environmental impacts by up to 45-87% depending on the type of irrigation used. When examining the global warming potential, it was found that the cultivation of Jatropha accounted for the highest share of GHG at 57.58%, followed by the biodiesel production process at 23.88%. On the other hand, vehicles employing B20 blend could replace 14.78% of fossil energy use and reduce 13.95% of GHG emissions per km, compared to pure diesel vehicle.