Chapter 7 - Life Cycle Assessment of Algal Biorefinery

Abstract

Biodiesel production from algae would not be economically favorable by itself. Other coproducts such as animal feed and biochemicals from algae have to be produced in order to utilize the full potential of algae nutrient composition and to fulfill the growing demand of protein for animal feed and biobased chemicals. With growing interest in such production schemes, several multiproducts from algae biorefinery systems are being researched. However, these schemes need to be assessed for their environmental impact performance before commercial implementation. In this context, this study deals with the life cycle assessment of an algae biorefinery system in India. Two schemes, (1) biodiesel and protein production from algae and (2) biodiesel, protein, and succinic acid, were compared with their respective fossil-based reference system. The assessment results show that the algal biorefinery system is favorable to the environment compared to the reference system. Among algae schemes, biodiesel, protein, and succinic acid production from algae is superior in carbon dioxide emission reduction and fossil oil consumption compared to the other scheme. A sensitivity study with variation in the algae protein, carbohydrate, and lipid composition indicated that lower protein content favors environmental impact reduction compared to high protein composition.