(708h) Comparative Evaluation of Electrocatalytic Processes for the Valorization of Lignin through Techno-Economic and Lifecycle Assessment

This study explores the potential of using electrochemical (EC) methods for valorizing lignin, a cell wall component of lignocellulosic biomass, into high-value compounds and biofuels. Traditional direct electroreduction and oxidation of lignin have faced challenges in efficiency and selectivity due to the requirement of high oxidation potentials and expensive, toxic electrodes, leading to uncontrolled degradation. We propose using a hydrogen atom transfer (HAT) mediator to achieve benzylic oxidation, enhancing efficiency and selectivity under milder conditions. The research employs the NREL model for ethanol production to assess the commercial viability of electrochemical lignin conversion. We conducted a techno-economic analysis (TEA) and a life cycle assessment (LCA) using BioSTEAM and GREET® 2022, respectively, to evaluate the process's economic and environmental impacts over 20 years. Sensitivity analysis was carried out to examine base case values extracted from the catalytic performance of phthalimide‐N‐oxyl (PINO) type HAT mediators. Our findings suggest that a 2,000 metric tonnes per day (tpd) biorefinery using this method could produce approximately 71.05 tpd of chemicals, with the electrochemical unit consuming 4.18% of the input energy. The operating cost for chemical production was estimated at $16.85/kg, with a total capital expenditure of $403,769 MM. The LCA revealed that employing economic allocation in ethanol production can lead to a 25% reduction in total CO2 emissions. The study indicates that integrating an electrochemical unit using a HAT mediator into second-generation biorefineries for lignin oxidation followed by a reduction in chemicals could offer additional revenue streams and lower environmental impacts compared to conventional methods.