Bioplastic feedstock production from microalgae with fuel co-products: A techno-economic and life cycle impact assessment

The current and future consumption of petroleum-based plastics, which will be 20% of global annual oil comsumption by 2050, is leading to the investigation and development of feedstock alternatives. Algae-based plastics offer a promising substitute that would decrease oil consumption, improve environmental impact, and in some cases even improve plastic performance. This study investigates the economic viability and environmental impact of an algae biorefinery that integrates the complementary functions of bioplastic feedstock (BPFS) and fuel production. The BPFS and biofuel biorefinery modeled herein includes nine different production scenarios. Performance of the facility was validated based on experimental systems with modeling work focusing on mass and energy balances of all required sub-processes in the production pathway. Results show that the minimum selling price of the BPFS is within the realm of economic competition with prices as low as $970 USD tonne(-1). Additionally, life cycle impact assessment results indicate drastic improvements in performance of the produced BPFS, with reductions in greenhouse gas emissions ranging between 67 and 116% compared to a petroleum-based plastic feedstock. These results indicate that an algae biorefinery focused on BPFS production and fuels has the potential to operate both economically and sustainably. Sensitivity analysis results, alternative co-products (given that fuels represent minimal value) and product market potential are also discussed.