Efficient Fast Fractionation of Biomass Using a Diol‐Based Deep Eutectic Solvent for Facilitating Enzymatic Hydrolysis and Obtaining High‐Quality Lignin

Abstract

Current DES pretreatment is often performed under relatively severer conditions with high temperature, long time, and high DES usage. This work studied a short‐time diol DES (deep eutectic solvent) pretreatment under mild conditions to fractionate bamboo, facilitate enzymatic hydrolysis, and obtain high‐quality lignin. At an optimized condition of 130 °C for 10 min, lignin and xylan removal reached 61.34% and 84.15%, with residual glucan showing an ~90% enzymatic hydrolysis yield. Equally important, the dissolved lignin could be readily recovered with 97.51% yield, exhibiting 96.65% β‐O‐4 preservation. The fractionation and lignin protection mechanisms were unveiled by XRD, FTIR, cellulose‐DP, 2D HSQC NMR, 31P NMR and GPC analysis. This study highlighted that short‐time fractionation of bamboo can be achieved by a diol‐based DES which is an ideal strategy to upgrade the lignocellulose biomass for high enzymatic hydrolysis yields and high‐quality lignin stream.

Uncovering Challenges for Complete Carbohydrate to Bioethanol Utilization in a Reductive Catalytic Fractionation Biorefinery

“…The carbohydrate pulps, for instance, perform very well as a substrate for the separate enzymatic hydrolysis and fermentation (SHF) with production of bioethanol in several publications already, ,, while also being more prone to saccharification compared to pulp from a classic organosolv pretreatment . However, the field of organosolv research is advancing and shows progress to improve both the quality of the lignin products and the pulp’s susceptibility to enzymatic hydrolysis. , Negative effects of the pulp with residual lignin on the subsequent biochemical conversion of the RCF pulp, including bioethanol production with Saccharomyces cerevisiae, are currently debated, for example, questioning the necessity of substantial additional washing steps or not of the resulting RCF pulps to achieve high bioethanol yields. Despite requiring more exploration, the observed discrepancies are most likely caused by process parameters such as feedstock type, solvent composition, process conditions, and catalyst type that impact the pulp properties and subsequently also affect both the saccharification and fermentation.…”