Abstract
Kinetic studies of the esterification of free fatty acid (FFA) of rubber seed oil (RSO) for biodiesel production was investigated in this work. Esterification of RSO was carried out in batch experiments using a 1 litre round bottom flask placed on a constant temperature magnetic stirrer. The effect of catalyst concentration (1 – 2.5 vol.%), methanol to oil ratio (1:5 – 1:2 v/v) and temperature (45 – 60o C) on the acid value (AV) of the fatty acid methyl ester (FAME) was investigated. Integral method of kinetic data analysis for constant volume batch reactor systems
was used to study the reaction kinetics with the assumption that the reaction was irreversible. The AV of the FAME was found to decrease as the catalyst concentration was increased. It was also observed that methanol to oil volume ratio of 1:2 gave the least AV as time for esterification reaction was increased. At a temperature of 55o
C, the least AV was recorded after esterification reaction time of 90 min. The kinetics of esterification revealed a second order reaction in FFA with an average rate constant of 0.267 L/mol min. Activation energy and collision frequency factor
were also estimated to be 21.2091 kJ/mol and 671.155 L/mol min respectively.