Energy and Environmental Benefits of Rapeseed Oil Replacing Diesel

Abstract

In this paper the benefits of rapeseed oil (RO) replacing petroleum diesel in transportation are evaluated, demonstrating that RO use displaces greenhouse gas (GHG) emissions and saves fossil energy. A systemic description of the RO chain in France has been implemented and GHG emissions and energy used throughout the life cycle have been calculated using alternative co-product credit procedures, namely a replacement method, three allocation approaches (mass, energy, economic) and ignoring co-product credits. The results show that the cultivation stage is particularly important, being responsible for 68% of the primary energy requirements and 87% of the GHG emissions of the RO “well-to-tank” system, mainly due to the use of fertilizers and related N₂O emissions. Considerable reductions in fossil fuel depletion and GHG emissions can be achieved by replacing petroleum diesel with rapeseed oil (0.9 MJ and 62 g CO₂eq per MJ of fossil diesel replaced), but optimum use of co-products is needed.

Keywords:

• Energy renewability
• GHG emissions
• Petroleum diesel
• Rapeseed oil

ACKNOWLEDGMENTS

The research presented in this paper has been supported by the Portuguese Science and Technology Foundation project PTDC/TRA/72996/2006: Biofuel systems for transportation in Portugal: A “well-to-wheels” integrated multi-objective assessment. The first author (J. Malça) gratefully acknowledges financial support from the Portuguese Science and Technology Foundation through grant SFRH/BD/30237/2006.