Chemical and mechanical pretreatment of oak wood for lignocellulosic fiber production

Abstract Lignocellulose, the most abundant renewable biomass resource, represents a promising alternative for reducing dependence on non-renewable fossil resources. While extensive research has been conducted on lignocellulose, its complex structural, consisting of interconnected cellulose, hemicellulose, and lignin, makes the efficient separation of its components challenging. Therefore, this study aimed to enhance its value as a biomass resource by disrupting the complex structure of lignocellulose and efficiently separating its major components. To achieve this, oak wood was pretreated with an acidified ethanol solution (60.0 wt% ethanol, 0.25 wt% H 2 SO 4 ) and an alkaline reagent (2.0 wt% and 5.0 wt% NaOH). This pretreatment resulted in the removal of up to 94.7% of lignin. Aqueous suspensions of fine lignocellulose fibers (LCF) with lignin contents of 9.7 wt%, 7.6 wt%, and 5.4 wt% were prepared by colloidal milling of oak wood pretreated with 5.0 wt% NaOH. A distinct Tyndall effect was observed in the suspensions, confirming the presence of dispersed particles and demonstrating the formation of a colloidal system. The prepared lignocellulose fibers were subsequently characterized using various analytical techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and dynamic light scattering (DLS).