Comparative Assessment of Biodiesel Production and Properties from Waste Cooking Liquor, Olive Oil, and Mustard Oil through Transesterification Process

This study presents a comparative experimental analysis of biodiesel production from waste cooking oil (WCO), mustard oil, and olive oil using a potassium hydroxide–methanol transesterification process. The objective was to evaluate how feedstock type influences biodiesel quality and compliance with ASTM D6751 standards. Key properties—density, kinematic viscosity, flash point, and calorific value—were measured and compared with conventional diesel fuel. Among the samples, mustard oil biodiesel showed the most balanced characteristics, with viscosity (4.81 cSt) and calorific value (42 MJ/kg) aligning with ASTM standards. WCO biodiesel exhibited the highest flash point (155 °C), ensuring safer storage, while olive oil biodiesel showed higher energy content (41.22 MJ/kg) but lower flash point (65 °C), suggesting incomplete transesterification. By performing a comparison of edible, non-edible, and waste oils under identical reaction conditions, this work establishes a clear relationship between feedstock composition and biodiesel quality. The results provide practical insight for selecting cost-effective, sustainable feedstocks suitable for biodiesel production in Bangladesh and similar developing regions.