Combination of twin-screw extruder and homogenizer to produce high-quality nanofibrillated cellulose with low energy consumption

The commercialization of cellulose nanofibrils (CNF) is limited due to the high energy consumed during production. Twin-screw extrusion has recently been employed for the energy-efficient production of CNF with high solid content, but the method requires several passes. Cellulose nanofibrils have been produced by using both a twin-screw extruder and a homogenizer. Some combinations require a fewer number of passes thereby using less energy, while maintaining the desired CNF quality. The morphology and quality of CNF were characterized by optical microscopy, MorFi analysis, and with a recently developed quality index. The combination of one pass through the twin-screw extruder and two passes through the homogenizer decreases energy consumption by 45%. These CNF have a similar quality to CNF produced after five passes through the homogenizer alone.