Abstract

The increase in the consumption of fossil fuels and environmental pollution caused by these fuels have been prompted researchers to produce renewable biodiesel fuels. Due to the high cost of biodiesel production, suitable catalyst design is highly efficient to increase efficiency and reduce biodiesel production time. The main objective of this research is to synthesize of Silica-Alumina-Phosphate nanostructure by hydrothermal method and to improve its structure in order to produce biodiesel by esterification reactions of free fatty acid. The fatty acid contained in the oil does not penetrate the Ce/SAPO-34 pores because of its large molecular size. To solve the penetration problem, the texture of the Ce/SAPO-34 was modified by the use of activated charcoal, and therefore meso and macro pores were formed in its structure. 4 wt.% of activated charcoal was determined to achieve a catalyst containing more meso and macro pores. Synthesized catalysts were evaluated by XRD, FESEM, BET/BJH analysis.The BET analysis showed that 4 wt.% of activated charcoal is the optimal amount of the hard template. The results of the reactor test showed that the synthesized nanocatalyst has the ability to convert 94% of the free fatty acid into biodiesel. The synthesized catalyst resulted in a conversion rate of 83% after 5 times of recovery, still maintaining its crystallinity.