New model analyses lifecycle biofuel emissions for EU

The model takes a holistic approach to emissions from second generation biorefineries, from production of feedstock, to refining and consumption. The goal is to give engineers a better idea of how to minimise greenhouse gases and make their refineries more economically viable.

By incorporating multiple sources of data, Edgard Gnansounou, a professor at École Polytechnique Fédérale de Lausanne’s (EPFL) and author of the study, said that he hopes to clarify how biofuels compare with fossil fuel emissions for both politicians and consumers.

“In my study, I wanted to show that calculating the greenhouse gas emissions of biofuels tells just half of the story. What we really need to do is quantify the emissions of each product coming out of biorefineries,” says Gnansounou.

Second-generation refineries use waste agricultural products rather than dedicated crops (which can be used for food) as a feedstock. The study focuses on a facility that used wheat straw as a feedstock, and analysed the emissions from the fertiliser and farm machinery during cultivation, and whether the land had been previously been used for other crops. After calculating a figure accounting for all these sources of GHGs, Gnansounou divided the total between each of the products produced by the refinery, which includes the biofuel, but also biogas and phenol, a compound used in the chemical industry.