Biodiesel synthesis from palm cooking oil utilising sulfuric acid catalyst in a circular microreactor: Optimisation using response surface method

Abstract

Biodiesel, a renewable and biodegradable fuel, has gained attention as a viable alternative to traditional petroleum-based diesel. Palm oil is an appealing raw material for biodiesel production due to its high oil yield, availability, and favourable fatty acid profile. Microreactor technology has improved the efficiency and control of chemical reactions, especially in biodiesel production. The key challenge is optimising reaction conditions to maximise Fatty Acid Methyl Ester (FAME) content while reducing the kinematic viscosity of the oil. To address this, the Response Surface Methodology (RSM) was employed. The effects of critical input variables such as catalyst loading, reaction temperature, and oil-to-methanol molar ratio on FAME yield and kinematic viscosity were analysed, and the optimal conditions were identified. Transesterification was carried out using a sulfuric acid catalyst in a circular microreactor, with a central composite design examining three input variables and two output variables. Results showed that catalyst loading, reaction temperature, and oil-to-methanol molar ratio significantly increased FAME content and lowered kinematic viscosity. The optimal conditions were determined to be 4.7% catalyst loading, a temperature of 66.8°C, and an oil-to-methanol molar ratio of 1:10.