Life-Cycle Assessment of Biofuels

Life-cycle assessment (LCA) is a powerful tool to evaluate economic efficiency and environmental impacts of a product or processes. One of its most important applications in the last decades—considering the debates around energetic matrix changes and the impacts of human activity over the environment—is on biofuels life cycle, where the main target is to compare the use of a certain biofuel (a renewable source of energy) with a fossil fuel. In the first part of this chapter, we briefly discuss LCA theory, scope and objectives, besides some of the commonly used parameters to evaluate and compare different processes efficiencies. In the sequence, we focus on some specificities of biofuels life cycle, and finally we present some case studies concerning the most important biofuels—biodiesel, bioethanol, and biohydrogen, among others.