Life-cycle GHG assessment of soybean biodiesel

This paper presents a life-cycle (LC) greenhouse gas (GHG) emissions assessment of biodiesel produced in Portugal, based on soybean cultivated in Latin-America. The implications of different cultivation systems and land use change (LUC) scenarios are assessed. Multifunctionality in the soybean biodiesel chain is also addressed, based on a sensitivity analysis to allocation approaches. The results show the importance of LUC on biodiesel GHG emissions but significant differences in the GHG balance have been observed for the alternative LUC and cultivation systems assessed. Degraded grassland should be preferably used for soybean cultivation. No-(reduced-) tillage systems have lower GHG emissions than the corresponding tillage systems. Multifunctionality is also an important issue since results are very sensitive to the approach adopted to treat co-products.