Conclusion
From the obtained results, using the conventional technique, the best yield % for the production of biodiesel from Jatropha oil was obtained using a methanol/oil molar ratio of 7.5:1, potassium hydroxide as catalyst (1.5%), and a reaction time of one hour with the reaction temperature maintained at 65 °C. The study also showed that the quality of the produced biodiesel satisfies the international American and European standards; hence, inedible vegetable oils such as Jatropha oil, produced by seed-bearing shrubs, can provide an alternative, and they do not have competing food uses.
The results showed that application of radio frequency microwave energy offers a fast, easy route to this valuable biofuel with advantages of enhancing the reaction rate and improving the separation process. The reaction time was reduced to 2 min instead of 150 minutes (90 min for the pretreatment process and 60 min for transesterification), because, by using the microwave technique, no pretreatment is required. The methodology also allows for the use of high free fatty acid content feedstock, including Jatropha oil. However, this will need time control, otherwise the yield may be affected.