Effects of drying temperature, airflow, and cut segment on drying rate and activation energy of elephant cassava

Abstract

One of the abundant raw materials of bioethanol is cassava; elephant cassava is a particular type of cassava that is physically larger than local cassava. When used to manufacture bioethanol, cassava must be dried for preservation and to avoid decay. This study was conducted to determine the drying kinetics of cassava. Briefly, the influence of drying temperature, airflow, and cut segment on drying rate and activation energy can be used as design references for drying machines that are optimal for elephant cassava. Two types of drying mechanisms were used: (1) natural convection drying used a moisture analysis, and (2) forced convection drying used a batch drying system in combination with a refrigeration system. Based on the experimental results, the lowest activation energy of 22.915 kJ/mol was obtained in the forced convection drying test at temperature 100 °C and dehumidified air supply of 360 L/min. In contrast, the highest activation energy of 27.17 kJ/mol was obtained in the natural convection drying test at temperature 60 °C without an air supply. The physical drying result of the forced convection test was better than the natural convection test, and the samples in the former were completely dried. Keywords: Bioethanol, Cassava drying, Forced convection, Moisture content, Natural convection