Study on the Preparation, Characterization of a Novel Solid Brönsted Acid Catalyst H3PW12O40/C and its Catalytic Performance in the Synthesis of Biodiesel via Esterification Reaction of Oleic Acid and Methanol

Waste camellia seed shell was placed in fluidized bed tubular reactor and carbonized at 700°C for the preparation of a carbon material, and which was then used as the support for the synthesis of a novel solid Brönsted acid catalyst H3PW12O40/C by impregnation of it with H3PW12O40 solution. The obtained H3PW12O40/C catalyst was characterized by scanning electron microscope, X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectoscopy, thermogravimetric analysis. The catalytic activity of H3PW12O40/C was evaluated from the esterification reaction of oleic acid with methanol, which was performed in a batch reactor. Results shown that the highest conversion of oleic acid was 75.83 wt% when the molar ratio of methanol to oleic acid was 10:1, reaction temperature was 60°C and catalyst loading was 1 wt% after 5 h. The high activity can be ascribed to the waste camellia seed shell-derived carbon material is mainly consisted of hydrophobic carbon sheet, which means that the adsorption of water on its Brönsted acid sites was reduced, so the hydration between Brönsted acid sites and H2O was also reduced. And eventually, the deactivation of Brönsted acid sites was reduced.