Esterification of Waste Palm Oil in Wastewater Pond for Community Biodiesel Production

The aim of this research was to develop a two-step technique to prepare biodiesel from waste palm oil (WPO) with high free fatty acid content. The developed process consists of esterification and transesterification steps. Response surface methodology (RSM) was applied for investigating the experimental design for esterification step. Design of experiment was performed by application of 5-levels-3-factors central composite design in order to study the optimum condition for decreasing FFA in WPO. The WPO with low FFA was further experimented in transesterification step to obtain fatty acid methyl ester (FAME). The investigated results showed that the WPO containing 48.62%wt of high FFA. The optimum condition of esterification step was 28 moles of methanol to FFA in WPO molar ratio, 5.5% sulfuric acid concentration in 90 min of reaction time and 60 °C of reaction temperature. After transesterification step, WPO biodiesel gave methyl ester content at 84.05% according to EN 14103 method. The properties of WPO methyl ester meet the standards of Thailand community biodiesel that can be used as fuel in agricultural machine.