(232e) Integrated Techno-Economic and Life Cycle Analysis of Reductive Catalytic Fractionation and Base-Catalyzed Depolymerization Hybrid Processing for Lignin Valorization

The chemical depolymerization of lignin is characterized by its non-selective nature, yielding a diverse array of lignin breakdown products (LBPs). To tackle this challenge and focus on generating specific high-value chemical commodities, a novel approach has been developed. This study aims to validate the industrial relevance of reductive catalytic fractionation (RCF) and base-catalyzed depolymerization (BCD) hybrid processing. Utilizing a comprehensive approach, including techno-economic analysis (TEA) and life cycle assessment (LCA), the research evaluates the economic and environmental impacts of these processes. Employing the National Renewable Energy Laboratory (NREL) cellulosic ethanol production model, we assess the commercial viability of electrochemical lignin conversion through a TEA and LCA implemented in BioSTEAM and GREET® 2023, respectively, over a 20-year period. A Pd/C catalyst was used for reductive catalytic fractionation (RCF) of poplar biomass, and Rhodococcus opacus PD630 (R. opacus) was subsequently cultivated on the resulting LBPs. Results indicate that RCF decreases the ethanol selling price from $4.07 to $3.93/gallon, while BCD increases it to $4.18/gallon. Global warming potentials range from 29.21 to 30.26 for RCF and from 27.53 to 28.43 for BCD. Notably, the carbon-negative effects range from -0.38 to –0.85 grams of CO2eq/MJ of ethanol for RCF, compared to -0.02 to -0.3 for BCD. Increasing lipid production emerges as a key factor in enhancing the economics and environmental impact of the lignin-first biorefinery concept.