Comparative assessment of response surface and Taguchi methods for biodiesel production from waste cooking oil

Biodiesel as a sustainable economical substitute to fossil fuels has gained significant attention because of its environmental benefits and potential for reducing dependence on non-renewable energy sources. Through transesterification, waste cooking oil (WCO) is converted to methyl ester. Yield of biodiesel is greatly impacted by critical factors such as catalyst ratio, reaction time, alcohol concentration, reaction temperature and stirring speed. The stirring speed ranged from 200 to 600 rpm, catalyst concentration from 0.75 to 1.25%, temperature of reaction from 50 to 70°C, reaction time from 30 to 90 min, and alcohol concentration from 10 to 30%. A total of 50 experimental runs were conducted under varying conditions. To forecast biodiesel yield and maximize the generation of biodiesel from WCO, this study compares the response surface methodology and Taguchi approach. While the Taguchi technique offered simplicity and experimental efficiency, RSM gave higher predicted accuracy and detailed insights into the interaction effects between variables. The reaction temperature had the greatest influence on biodiesel synthesis, as confirmed by both RSM and Taguchi approaches. Both approaches produced the optimum biodiesel yields when the molar ratio of methanol was 10:1, the catalyst concentration was 1.5% by weight, the reaction temperature was 65°C, and the reaction period was around 2 h. Analysis of Variance (ANOVA) showed that the actual and projected values were agreed well. While alcohol content and stirring speed had no influence on S/N ratio, reaction temperature demonstrated the greatest S/N ratio. With high yield and process stability guaranteed, this dual strategy provides a dependable route for biodiesel production optimization. By encouraging the conversion of waste into energy, WCO as a feedstock helps to maintain a sustainable environment.