Drying kinetics of cellulose nanofibers suspensions

Cellulose nanofibers (CNF) is used in various pharmaceutical applications due to its unique characteristics i.e., biodegradability, mechanical and biological properties. CNF is often produced by spray drying process, knowledge of the drying kinetics in terms of mass and heat transfer on the scale of single droplet is important for process development and model validation. Acoustic levitator was used to study drying process of CNF suspension at different air temperatures and initial CNF concentrations. The unique property of acoustic levitation to hold single droplet contactless in the air, enables to study particle morphology during drying process, calculate evaporation rate and estimate particle porosity. Results show that packed particles result at lower initial concentration and temperature has a moderate influence on mean porosity of CNF dried particles. Keywords: acoustic levitation; droplet; drying kinetics; Cellulose Nanofibers