Integrated techno-economic and environmental assessment of biorefineries: review and future research directions

Abstract

Biorefineries will be strategic players in achieving the circular economy and sustainability goals. This work presents a comprehensive review of the last decade of research on the Environmental and Techno-Economic Assessment (ETEA) of biorefineries. We compiled 102 articles applying an integrated ETEA approach to understand the technical, economic, and environmental implications of different biorefinery schemes. Bibliometric analysis has been first performed to map the keywords and locations of case studies and explore trends in biomass feedstock, conversion routes, and bio-based products. Then, computer-aided tools and state-of-the-art methodologies employed within the ETEA framework are reviewed. Finally, challenges and directions for research are discussed. The results show increasing interest in the topic, moving from the first to higher generations. Publications utilizing second-generation biomass dominate the research topic (65%), followed by the third, first, and fourth generations (16, 12, and 1%, respectively). An uneven distribution of publications was also observed, with the USA contributing the most (with one-third of studies), suggesting that governments are crucial driving forces of research. Biochemical routes such as fermentation and anaerobic digestion receive the most attention (together used in 59 out of the 102 articles), followed by thermochemical routes (e.g., combustion, pyrolysis, and gasification used in 28% of the articles). Bioethanol is the main targeted product (in 29 articles), followed by biogas, biomethane, and biodiesel. Overall, the ETEA framework aids in designing and optimizing biorefineries to achieve sustainability goals. It helps evaluate the trade-offs between the economic viability and environmental sustainability of conventional and emerging biorefinery processes at different stages of deployment. This review contributes to the development of the ETEA framework, and it might be helpful to guide practitioners, decision-making, and future research on sustainable biorefineries.