This paper presents an optimization study in the production of biodiesel production from Marula oil. The study was carried out using a central composite design of experiments under response surface methodology. A mathematical model was developed to correlate the transesterification process variables to biodiesel yield. The transesterification reaction variables were methanol to oil ratio, x1 (10-50 wt %), reaction time, x2 (30-90 min), reaction temperature, x3 (30-90 °C) stirring speed, x4 (100-400 rpm) and amount of catalyst, x5 (0.5-1.5 g). The optimum conditions for the production of the biodiesel were found to be: methanol to oil ratio (29.43 wt %), reaction time (59.17 minutes), reaction temperature (58.80°C), stirring speed (325 rpm) and amount of catalyst (1.02 g). The optimum yield of biodiesel that can be produced was 95 %. The results revealed that the crucial fuel properties of the biodiesel produced at the optimum conditions met the ASTM biodiesel specifications.


Christopher C Enweremadu and Hilary L Rutto