Recent Progress in Electrochemical Upgrading of Bio-Oil Model Compounds and Bio-Oils to Renewable Fuels and Platform Chemicals

• Published in: Materials Vol. 16; no. 1; p. 394
• Main Authors: Page, Jeffrey R, Manfredi, Zachary, Bliznakov, Stoyan, Valla, Julia A
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-01-2023; MDPI
• Subjects: Alternative energy sources; bio-oil upgrading; Biodiesel fuels; Biofuels; Biological products; Biomass; biomass conversion; Biomass energy; Biomass energy production; Carbon; Catalytic cracking; Chemical engineering; Chemical engineering research; Chemical properties; Chemicals; Commercialization; Design optimization; Efficiency; Electric properties; Electricity; electrocatalysis; Electrochemical reactions; Electrodes; Electrolytes; External pressure; Fuel; Harnesses; High temperature; Hydrogen; Hydrogenation; Lignocellulose; Low temperature; Oils and fats; Oxidation; Production processes; Raw materials; renewable hydrogen; Renewable resources; Review; Solar energy; Upgrading; United States; United States > US; biomass conversion; bio-oil upgrading; electrocatalysis; renewable hydrogen
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16010394

Sustainable production of renewable carbon-based fuels and chemicals remains a necessary but immense challenge in the fight against climate change. Bio-oil derived from lignocellulosic biomass requires energy-intense upgrading to produce usable fuels or chemicals. Traditional upgrading methods such as hydrodeoxygenation (HDO) require high temperatures (200−400 °C) and 200 bar of external hydrogen. Electrochemical hydrogenation (ECH), on the other hand, operates at low temperatures (<80 °C), ambient pressure, and does not require an external hydrogen source. These environmental and economically favorable conditions make ECH a promising alternative to conventional thermochemical upgrading processes. ECH combines renewable electricity with biomass conversion and harnesses intermediately generated electricity to produce drop-in biofuels. This review aims to summarize recent studies on bio-oil upgrading using ECH focusing on the development of novel catalytic materials and factors impacting ECH efficiency and products. Here, electrode design, reaction temperature, applied overpotential, and electrolytes are analyzed for their impacts on overall ECH performance. We find that through careful reaction optimization and electrode design, ECH reactions can be tailored to be efficient and selective for the production of renewable fuels and chemicals. Preliminary economic and environmental assessments have shown that ECH can be viable alternative to convention upgrading technologies with the potential to reduce CO2 emissions by 3 times compared to thermochemical upgrading. While the field of electrochemical upgrading of bio-oil has additional challenges before commercialization, this review finds ECH a promising avenue to produce renewable carbon-based drop-in biofuels. Finally, based on the analyses presented in this review, directions for future research areas and optimization are suggested.