Improved Chemical Reactivity of Lignocellulose from High Solids Content Micro-fibrillation by Twin-screw Extrusion

The low reactivity of lignocellulose limits the effective chemical conversion of lignocellulose biomass into functional bioproducts. Mechanical micro-fibrillation treatment can improve the chemical accessibility of lignocellulose but usually has limited productivity by the low processing solids content. The presented work demonstrates effective micro-fibrillation of lignocellulose at high solids content up to 60 wt% can be achieved by twin-screw extrusion. Morphological characterizations of the extruded wood pulp lignocellulose show the degree of micro-fibrillation is enhanced by operating at higher solids content. The lignocellulose treated at 60 wt% solids content presents 2.1 and 4.8 times higher water retention capacity and specific surface area, respectively, than the original material. Acetylation results show the twin-screw extrusion pre-treatment can significantly accelerate the chemical modification of lignocellulose by 50%. This high productivity method for micro-fibrillating lignocellulose should be of great interest to the bioplastics industry.