Umudike Journal of Engineering and Technology

The environmental hazards of waste cooking oil (WCO) in our society has raised a lot of concern and spurred researchers to harness its reuse. This work statistically assessed the process conditions for biodiesel production from waste cooking oil (WCO) collected from restaurants in Enugu metropolis. The central composite design of Response Surface Methodology (RSM) was carried out and the results were analyzed using the MINITAB SOFTWARE 14.0. A 5-level-2-factors experimental was designed which gave a 25 experimental runs with full randomization and zero centre points. Methanol-to-oil molar ratio of (1:3, 1:4, 1:6, and 1:8) and weight of catalyst (0.2 0.3g, 0.5g, 0.8g, and 1.0g) were used as independent variables (factors) and biodiesel yield as dependent variable (response) in transesterification reaction. Analysis of variance (ANOVA) was used to statistically analyze the experimental matrix. The variables were later fitted in a second order quadratic polynomial regression model showing the effect of catalyst and molar ratio on yield of biodiesel with the use of interaction, main effect, contour and surface plots. The experimental results suggested that a yield of 30.89% was achieved at methanol/oil molar ratio of 1:9 and catalyst weight of 0.2 while maintaining the model fit at 29.677 which resulted in coefficient of determination (R²) of 91.3%. In conclusion, biodiesel derived from waste cooking oil showed a closer properties relationship with EN14214 biodiesel standard.