biodiesel production using clay-based material as an eco-friendly catalyst: effect of calcination temperature

Biodiesel production from the esterification of oleic acid was performed by using low-cost kaolin clay. the kaolin clay was advantageous not only for its cost-efficiency but also for its superior catalysis in the esterification of fatty acid to produce biodiesel. the effect of calcination temperatures on the activity of the catalyst was investigated. the results showed that the highest activity with >75% conversion belonged to the not-calcined sample when applied to the esterification of oleic acid at methanol: oil molar ratio of 20:1 at 110°c for 4 h. structure and properties of the catalyst were studied, and the characterizations with xrd and fesem analyses demonstrated that the performance of the catalyst was closely related to its crystalline structure. in particular, the reduction of crystalline kaolinite worsened the catalytic activity.