Environmental Impacts of Biofuels: The GHG Emissions Saving

One of the aims for the utilization of biofuels is the climate change mitigation through the reduction of GHG emissions in the transport sector. Measuring the con­sequences of biofuels requires consideration of their full life cycle, from biomass pro­duction and its use of various inputs to the conversion of feedstocks into liquid fuels and the subsequent use of the biofuels in combustion engines (Rasetti et al. 2012).

The potential mitigation varies across types of feedstock, feedstock production process/technology (e. g., usage of nitrogen fertilizer), and fossil fuel consumption in both production of feedstocks and its conversion to biofuels.

Several standard life cycle analyses (LCA) of biofuels in the literature have reported a wide variation on the reduction of GHG emissions; this is mainly due to differences on underlying assumptions on system boundaries, by-product alloca­tion, and energy sources used in the production of agricultural inputs and feedstock conversion to biofuels. Most studies (Sims et al. 2010; Rutz and Janssen 2007) indicate that biofuels show some emission reductions when compared to their fossil fuel counterparts, especially when the emissions from the director indirect land-use changes (LUC/ILUC) due to biofuels feedstock production are excluded.