SusChEM: Continuous Flow Lignin Deconstruction in Supercritical Solvent Mixtures and Conversion to Renewable Chemicals

Iowa State University, Ames IA

Investigators

Abstract

Lignocellulosic biomass from agricultural waste and non-edible plants represents an abundant, inexpensive, and renewable source of carbon for the production of bio-based fuels, chemicals, and polymers. To be truly sustainable, new conversion processes that favor the use of green solvents, non-precious metal catalysts, and offer optimal biomass utilization need to be explored. The research objective of this project is to investigate the deconstruction of lignin, an underutilized biopolymer which accounts for up to 30% of lignocellulosic biomass, and its conversion to high value-added bio-based phenolic precursors for the industrial production of drugs, cosmetics, flavoring agents, and epoxy resins. The process combines the depolymerization of lignin in supercritical solvents and the catalytic upgrading of the resulting fragments to desired bio-based products. The project will explore new processes to convert lignin, an industrial waste product that is currently burnt as low value boiler fuel, to high value-added chemicals of industrial significance. Specifically, the deconstruction and fractionation of industrial lignin in flow reactors using supercritical solvent mixtures will be studied in order to understand the involved mechanisms and identify conditions that favor high selectivity, thus benefiting the economics of the conversion process and the environment by reducing waste. High value building blocks such as p-coumaric acid and ferulic acid will be recovered while fractions with lower value monomers and oligomers will be further converted over nanostructured catalysts to bio-based phenolic platform chemicals. The outreach program primarily targets grades 7-12 high school teachers with the objective of generating excitement and interest in pursuing careers in STEM fields among their students.