Green Deep Eutectic Solvents for Microwave-Assisted Biomass Delignification and Valorisation

Aiming to fulfil the sustainability criteria of future biorefineries, a novel biomass pretreatment combining natural deep eutectic solvents (NaDESs) and microwave (MW) technology was developed. Results showed that NaDESs have a high potential as green solvents for lignin fractionation/recovery and sugar release in the following enzymatic hydrolysis. A new class of lignin derived NaDESs (LigDESs) was also investigated, showing promising effects in wheat straw delignification. MW irradiation enabled a fast pretreatment under mild condition (120 degrees C, 30 min). To better understand the interaction of MW with these green solvents, the dielectric properties of NaDESs were investigated. Furthermore, a NaDES using the lignin recovered from biomass pretreatment as hydrogen bond donor was prepared, thus paving the way for a closed-loop biorefinery process.

Automated summary

A novel biomass pretreatment method combining NaDESs and MW technology was developed to meet the sustainability criteria of future biorefineries. NaDESs were found to be effective green solvents for lignin fractionation and sugar release, with LigDESs showing promising effects in wheat straw delignification. The use of MW irradiation allowed for fast pretreatment under mild conditions, paving the way for a closed-loop biorefinery process.