Drying of oil palm frond particles in a fluidized bed dryer with inert medium

Abstract

Drying characteristic of oil palm frond fibres was investigated in a fluidized bed dryer with the presence of inert particles. Sand was used as inert material. Effects of air temperature (60, 70 and 80ºC), air velocity (0.79 and 0.85 m/s) and mass ratio of fibres to sand (1:0, 1:1 and 1:2) on the drying curves were investigated. The results showed that the shortest drying time was obtained with the highest air temperature, air velocity and fibres to sand mass ratio. The experimental drying data were fitted to nine existing drying models namely Lewis, Page, Modified Page, Henderson and Pabis, Logarithmic, Two-term, Two-term exponential and Wang and Singh models and a proposed new model. The goodness-of-fit was determined based on the values of r2, c2 and RMSE. The results showed that the best quality of the fit was obtained using the proposed model. The new model was also validated for the superheated steam drying of oil palm empty fruit bunch from other work.

Keywords

• drying characteristics
• drying kinetics
• falling rate
• fibrous material
• fluidized bed
• inert particles