Life cycle assessment of biodiesel production from rapeseed oil: Influence of process parameters and scale

Biodiesel has the potential to mitigate the fossil fuel-related carbon emission and energy insecurity challenges. There are limited studies examining the impacts of biodiesel production scales on the environmental impacts, while such information will be valuable for guiding practical system design. This work applied the approach of life cycle assessment to evaluate the environmental impacts of biodiesel production from rapeseed oil which accounts for 80% of the European biofuel market. It was shown that the centralized large-scale and localized small-scale biodiesel production schemes have annual global warming potential (GWP) of 2.63 and 2.88 tCO₂-eq/t biodiesel, where the rapeseed agriculture stage caused more than 65% carbon emissions. Sensitivity analysis revealed a high dependence of GWP on rapeseed yields, glycerol re-utilization strategy, and nitrogen nutrient in fertilizer. An alternative scenario was proposed for the large- and small-scale systems that could reduce carbon emissions by 14.1% and 33.6%.