Parametric studies on pretreatment of lignocellulosic biomass via deep eutectic solvents: Enhancing densified pellet quality

Abstract

Densified pellets derived from lignocellulosic biomass are attractive candidates for alleviating energy constraints and replacing fossil fuels. However, the undesirable properties of lignocellulosic biomass and the resulting high costs of handling have hampered its widespread application. In the present study, we introduce a pretreatment strategy for lignocellulosic biomass to produce high quality densified pellets. In this process, the structure of lignocellulosic biomass was deconstructed and lignin was regenerated in situ, resulting in a homogeneous cellulose-lignin slurry. The resulting densified pellet exhibits higher density (up to ∼1200 kg/m3), strong mechanical strength (maximum increase to ∼12 N/mm2), better water resistance (decreased from 15% to 10%), and improved combustion characteristics (enhanced nearly twice). The improved performance indicates that the combination of deep eutectic solvent treatment with densification is an efficient way to develop processing schemes for sustainable and efficient utilization of lignocellulosic biomass.