Microfibrillated cellulose and cellulose nanopaper from Miscanthus biogas production residue

The feasibility of the isolation of microfibrillated cellulose (MFC) from the fibrous residue of the production of biogas from Miscanthus straw was investigated. Studying two variants of continuous anaerobic fermentation carried out at mesophilic and thermophilic conditions, respectively, MFC was obtained after extensive extraction of non-cellulosic compounds and mechanical fibrillation. MFC crystallinity and molar mass were drastically decreased in biogas residue with increasing temperature in processing. Nonetheless, nanopaper produced from all variants showed acceptable mechanical performance considering its significantly degraded structure. High failure strain at low density is of particular interest for the thermophilic variant. Infrared spectroscopy indicates changes in surface chemistry of the thermophilic variant, which may explain its peculiar tensile properties. Production of fibrillated cellulose from biogas residue is suggested as highly interesting route for the generation of additional value from bioenergy processes.