Glycerolysis-Based Reduction of Free Fatty Acids in Crude Palm Oil (CPO) for Cost Effective Biodiesel Pre-Treatment

Abstract

The high content of free fatty acids (FFA) in crude palm oil (CPO) presents a significant challenge for biodiesel production. This study investigates the glycerolysis pretreatment method using crude glycerol and potassium hydroxide (KOH) to reduce FFAs. Experiments were performed at varying molar ratios (1:3 to 1:9) and temperatures (60°C to 80°C). Results showed optimal FFA reduction at a 1:7 molar ratio and 80°C, reducing FFA below 5% within 60 minutes. FTIR analysis confirmed FFA conversion. The reaction followed a pseudo-second-order kinetic model (R² = 0.9832). Viscosity and density of the oil improved to 41.2 mPa·s and 0.886 g/cm³, respectively. These findings demonstrate that glycerolysis is a promising, eco-friendly, and cost-effective solution for pretreating high-FFA feedstock in biodiesel production.