Spouted Bed Drying of Oil Palm Frond Particles

Abstract

Oil palm frond has been used for many applications especially as a source of industrial fibers. Drying of oil palm frond particles is essential before the material could be used for subsequent applications. This research aimed to study the drying kinetics of oil palm frond particles in a spouted bed dryer. Spouted bed dryer has been used by various industries because of its ability to dry large size and irregular shape particles. In this research, experiments were conducted to study the effect of various operating variables on the drying kinetics of oil palm frond particles in a spouted bed dryer. The manipulated variables were hot air temperature, superficial air velocity and bed height. Batch drying experiments of oil palm frond particles were performed by varying the hot air superficial velocity (1.3 m/s, 1.5 m/s and 1.6 m/s), temperature of hot air (50⁰C, 60⁰C and 70⁰C) and bed height (10 cm and 15 cm). For comparison purposes, samples of oil palm fronds were also dried under the sun. The fiber color changes subjected to two different drying methods were also observed. Drying kinetic results from the spouted bed drying experiments indicated that the drying duration decreased with an increased in air temperature and air velocity and a decreased in bed height. The color of the fiber from spouted bed dryer was less deteriorated compared to that dried by direct sun drying. Drying of oil palm fronds in a spouted bed dryer produced fibers that were lighter in color than the product dried by sun drying.