Understanding important aspects of spray drying microfibrillated cellulose through statistical analysis

Dewatering microfibrillated cellulose (MFC) is important from a commercial point of view. However, there are many issues related to this process still to be overcome, and operational suitability of different methods as well as their effects on dried particles are among the most discussed topics in this field. An exploratory work was conducted to study important aspects of drying MFC using the spray drying method. A statistical design of experiment was utilized to identify the individual and combined effect of important drying parameters (temperature, blower speed, feed rate and solids content) in yield and productivity to optimize the process. Two models were generated to describe these responses. The maximum values were 51.8% for yield and 6.14 g/h for productivity, not simultaneously. Additionally, the capability of MFC powder to redisperse in water was evaluated using carboxymethylcellulose as a blocking agent during the spray drying. This additive allowed dried MFC to redisperse and retain the properties of never dried suspension.