Co-production of 1,4-pentanediol and adipic acid from corn stover with biomass-derived co-solvent: Process synthesis and analysis

Abstract

As environmental issues caused by the use of fossil-derived chemicals arise, efforts to replace fossil-based feedstocks with renewable and environment-friendly resources to mitigate the environmental impact of chemical production have been continuously made. In this study, an integrated process utilizing separation and catalytic conversion was designed to co-produce adipic acid (ADA), a precursor used to produce nylon 6.6, and 1,4-pentanediol (1,4-PDO), a monomer for biodegradable polymer, from corn stover as a renewable resource. Cellulose and hemicellulose are simultaneously converted into gamma-valerolactone (GVL), and the GVL is further split and converted into ADA and 1,4-PDO. The energy consumption for the process is significantly reduced by designing and incorporating a heat exchanger network. Techno-economic analysis and life cycle assessment were performed to evaluate the economic and environmental impacts of the three representative cases having different GVL split ratios for ADA and 1,4-PDO production. The results indicate that the case producing the most ADA leads to an optimal minimum selling price of $1382/ton ADA under the proposed assumptions and has a marginal impact on the environment compared to the fossil-based ADA production. Uncertainty analysis showed that this co-production process has economic stability against variable market conditions. These results suggest directions to improve the economic and environmental feasibility of the proposed process.