Microalgal Proteins to Bioplastics: Techno-Economic and Life Cycle Assessment

The low price of petroleum-based fuels and the high capital costs of algal growth architectures have made it challenging for microalgae-derived fuels to compete in the market. Over the last decade, researchers have been focusing on a variety of alternative co-products such as nutraceuticals, cosmetics, pharmaceuticals, and animal feed. Nonetheless, the quality of the protein plays an important role in the determination of the most suitable co-product. Given their large market size and relatively high value, bioplastics are a promising alternative for low quality protein biomass. This study explores the economic and sustainability implications of a bioplastic biorefinery with biofuels co-products. The model of our system includes the different sub-processes involved in the production of bioplastic feedstock and has been validated by experimental data. A total of nine scenarios were modeled, each with different levels of processing. A techno-economic and life cycle assessment were performed to determine the economic viability and environmental impact of bioplastic production. Results indicate significant improvements in environmental performance of the produced bioplastic feedstock, with reductions ranging between 67-116% compared to petroleum based plastic resins. Additionally, the minimum selling price of the bioplastic feedstock is within the range of economic competition with prices as low as $970 USD tonne^-1. These results indicate that an algae biorefinery focused on bioplastic feedstock production and fuels have significant potential to operate both economically and sustainably.