A novel high-speed homogenizer assisted process intensification technique for biodiesel production using soya acid oil: Process optimization, kinetic and thermodynamic modelling

Acid oils, which are readily available and cost-effective, show promise as a feedstock for biodiesel synthesis. This study focuses on biodiesel production using soya acid oil having high free fatty acids (FFAs) content of 80.65 %. Biodiesel is produced from high-FFA soya acid oil by employing a novel high speed homogenizer technique through esterification process followed by neutralization step. The process variables affecting esterification reaction have been optimized through response surface methodology (RSM) based Box-Behnken Design (BBD) technique. A maximum FFA conversion of 98.06 % was found at a M:O molar proportion of 18.41:1, a process time of 84.62 min, a catalyst amount of 2.18 wt%, and a rotational speed of 14,100 RPM. The determined activation energy for esterification reaction using high speed homogenizer was 36.82 kJ/mol, which is 1.5 to 2 times lower compared to conventional techniques. Thermodynamic behaviour of esterification reaction was studied and analysed. The resulting biodiesel after the neutralization step meets the EN 14214 standard for conversion rate (minimum 96.5 %) and physicochemical properties, ensuring commercial viability.