Evaluating ultra-fine friction grinding for the continuous production of nanofibrillated cellulose

Nanofibrillated cellulose (NFC) has diverse applications, but economical large-scale production with minimized ecological footprint remains challenging. A Masuko Supermasscolloider was modified for continuous processing using a pump-controlled circulating system, an in-line viscosimeter, and power consumption meters. Utilizing the upgraded system, we investigated NFC production from Miscanthus biomass under various conditions: different initial cellulose concentrations (1, 1.5, and 2 wt%), process volumes (15 and 25 L) and different grinding times (15-120 minutes, 15 min intervals). Particle size analysis showed equivalent hydrodynamic diameters of 200-300 nm regardless of processing conditions. Notably, our approach demonstrated 70 % reduction in specific energy consumption by simultaneously increasing process volume from 15 L to 25 L and initial cellulose concentration from 1 wt% to 2 wt%. Additionally, NFC produced at different grinding times was used to prepare carboxymethyl cellulose nanocomposites. Tensile testing demonstrated the same level of mechanical reinforcement regardless of NFC grinding time, highlighting a clear opportunity to reduce the footprint of NFC production while maintaining performance.