Carbon footprint and energy balance of biodiesel produced from tannery fleshings

This paper analyzes, from a life cycle perspective, the environmental performance of biodiesel obtained from leather industry fleshing waste (BDF). The indicators used for this environmental evaluation are: global warming potential (GWP) and energy return on investment (EROI). The contribution of each process-step in both GWP and EROI was determined. Transesterification of fat to obtain the BDF has been proved to be the most significant step in the process, mainly due to the consumption of methanol. A comparison between BDF and petroleum diesel obtained from non-renewable oil has also been performed using the same indicators. The results show a clear preference for BDF, although data from industrial real plants has to be considered in further works for BDF process to provide more accurate results.