Factors affecting transesterification of palm oil into biodiesel in the presence of NaOH and ZrO2

Abstract

In this study, a basic heterogeneous catalyst, NaOH/ZrO2, was used for the transesterification of palm oil into biodiesel. To determine the optimum condition for producing biodiesel, many parameters were investigated, including %NaOH loaded on zirconia support, amount of catalyst, reaction time, methanol to oil ratio, reaction temperature, and calcination temperature of the catalyst. The results showed that 91% of %conversion can be obtained by the transesterification of palm oil using 1% NaOH in methanol loaded on zirconia as heterogeneous catalyst. The optimal conditions were to use 1:15 molar ratio of oil to methanol with the addition of 3% catalyst, and heating for 90 min at 70°C. The fatty acid methyl ester product was analyzed its content using gas chromatography, as followed EN 14103, and found around 92%. The biodiesel obtained was investigated its properties, and found 0.23% linolenic acid methyl ester; 4.54 cSt of kinematic viscosity; 182±2°c flash point, and 40858±199.50 kJ/kg heating value. Furthermore, the preliminary study of re-used catalyst indicated that the used NaOH/ZrO2 catalyst could not be directly reused for transesterification reaction without further treatment. However, it could be easily regenerated and resulted in the same activity as the fresh catalyst.