Solvent‐Enabled Nonenyzmatic Sugar Production from Biomass for Chemical and Biological Upgrading

Abstract We recently reported a nonenzymatic biomass deconstruction process for producing carbohydrates using homogeneous mixtures of γ‐valerolactone (GVL) and water as a solvent. A key step in this process is the separation of the GVL from the aqueous phase, enabling GVL recycling and the production of a concentrated aqueous carbohydrate solution. In this study, we demonstrate that phenolic solvents— sec ‐butylphenol, nonylphenol, and lignin‐derived propyl guaiacol—are effective at separating GVL from the aqueous phase using only small amounts of solvent (0.5 g per g of the original water, GVL, and sugar hydrolysate). Furthermore, using nonylphenol, we produced a hydrolysate that supported robust growth and high yields of ethanol (0.49 g EtOH per g glucose) at an industrially relevant concentration (50.8 g L −1 EtOH). These results suggest that using phenolic solvents could be an interesting solution for separating and/or detoxifying aqueous carbohydrate solutions produced using GVL‐based biomass deconstruction processes.