Fig.2. Effect of temperature on moisture ratio of coconut residue in the fluidized bed dryer
Drying curve of coconut residue during fluidized bed drying was found only in the falling rate period, and there was no constant rate drying period in these curves. It was observed that moisture ratio diminished dramatically in the early stage of drying, and ultimately changed a bit when close it was to desirable moisture content of around 0.084 gwater/gdry matter. As expected, the higher drying temperature, the faster process to dry a sample to final moisture content of around 0.084 gwater/gdry matter. Using the highest level of drying temperature of 100°C resulted in the highest drying rate of coconut residue.
B. Modeling Drying Kinetics
The non-linear regression analysis was used to determine the suitable mathematical modeling that best describes the fluidized bed drying of coconut residue. Four empirical models were fitted to the drying curve in order to select the best model for describing the drying curve. The average moisture contents data were observed in gwater/gdry matter during the fluidized bed drying at various different temperatures.