Regional and temporal sustainability assessment of agricultural-based biodiesel

Although the world energy mix is still strongly dependent on fossil fuels, biofuels have been gaining market share, especially in the transport sector. The main biofuel raw materials are those produced by agropastoral systems that use large expanses of land. The present work presents an innovative method of sustainability assessment of biodiesel, combining temporal and regional approaches based on its three pillars. The method aims to ascertain whether a determined region, whose main economic activities are agropastoral and processing of agricultural raw materials, is moving toward or away from sustainability. The work integrates tools to evaluate land use change from satellite images with life-cycle assessment, to obtain greenhouse gas (GHG) emissions as the environmental metric. The economic and social metrics are the time derivative of per capita gross domestic product and the school enrolment ratio. The improvement of agropastoral/industrial activities in the region directly reflects the changes of the three metrics. The proposed method was applied to assess the sustainability of biodiesel produced from soybean oil and beef tallow in a micro-region of Central Brazil, in the period from 2003 to 2013. The case study revealed a reduction of 10% in sustainability, with improvements of 344% and 15% in the economic and social metrics but a decline of 1106% in the environmental metric. The results also showed that for both biodiesel made from soy oil and tallow, land use change is responsible for 97% of GHG emissions. The conclusion is that the implementation of automation of agricultural processes, with consequent increase in productivity, besides diminishing the environmental impact, would lead to an increase in gross domestic product indices and in the average schooling level, thus contributing to reduce social inequalities and increase the sustainability of agricultural-based biodiesel. Graphic abstract