A waste-free biorefinery pathway to the valorisation of Chinese hickory shell through alkaline hydrogen peroxide pretreatment

Abstract

Efficiently harnessing the intrinsic value of lignocellulose requires the integration of multifarious capacities within a zero-waste biorefinery. Chinese hickory shell, a food industry byproduct, remains largely untapped. Unleashing their full potential as a valuable biomass resource has become an urgent challenge. This study utilises the alkaline hydrogen peroxide pretreatment for Chinese hickory shell, exploring the effect of H2O2 dosage, alkali concentration, and temperature on lignocellulosic fractionation. Under optimal conditions, nearly complete removal of lignin and hemicelluloses is achieved, with cellulose enzymatic hydrolysis up to 98.1%, surpassing the original material by over 15-fold. Simultaneously, hemicelluloses transformed into high-value organic acids, yielding 33.5%. Notably, fractionated lignin is abundant in aryl ether linkages after AHP, facilitating subsequent transformation into aromatic chemicals. Through AHP, efficient fractionation of Chinese hickory shell is achieved, yielding fermentable glucose, organic acids, and lignin enriched with high aryl ether content. This research emphasises the pivotal role of comprehensive Chinese hickory shell utilisation in elevating the revenue of zero-waste biorefinery, sparking the production of valuable products from biomass waste streams, and further contributing to establishing resource-efficient biorefineries.