A review of thermochemical upgrading of pyrolysis bio-oil: Techno-economic analysis, life cycle assessment, and technology readiness

Technologies for upgrading fast pyrolysis bio-oil to drop-in fuels and coproducts are under development and show promise for decarbonizing energy supply for transportation and chemicals markets. The successful commercialization of these fuels and the technologies deployed to produce them depend on production costs, scalability, and yield. To meet environmental regulations, pyrolysis-based biofuels need to adhere to life cycle greenhouse gas intensity standards relative to their petroleum-based counterparts. We review literature on fast pyrolysis bio-oil upgrading and explore key metrics that influence their commercial viability through life cycle assessment (LCA) and techno-economic analysis (TEA) methods together with technology readiness level (TRL) evaluation. We investigate the trade-offs among economic, environmental, and technological metrics derived from these methods for individual technologies as a means of understanding their nearness to commercialization. Although the technologies reviewed have not attained commercial investment, some have been pilot tested. Predicting the projected performance at scale-up through models can, with industrial experience, guide decision-making to competitively meet energy policy goals. LCA and TEA methods that ensure consistent and reproducible models at a given TRL are needed to compare alternative technologies. This study highlights the importance of integrated analysis of multiple economic, environmental, and technological metrics for understanding performance prospects and barriers among early stage technologies.