Mesoporous Al-Mo Oxides as an Effective and Stable Catalyst for the Synthesis of Biodiesel from the Esterification of Free-Fatty Acids in Non-edible Oils

摘要

A kind of mesoporous Al-Mo mixed oxides as solid acid catalysts was designed and prepared through a facile and low-cost approach using stearic acid as a soft modifier, and investigated by X-ray diffraction, thermogravimetric, fourier transform infrared spectra, N-2 adsorption-desorption, ammonia temperature programmed desorption and scanning electron microscopy. By using this catalyst, an environmentally benign process for esterification of free-fatty acids in non-edible Euphorbia lathyris crude oil with methanol was developed. It was shown that the activity of the catalysts for the esterification reaction is closely related to their mesoporous structures, surface area and acid properties. The Al-Mo solid acid catalyst exhibited an optimal esterification performance with 80.9% esterification efficiency under the optimum synthesis conditions. Moreover, the conversion remained over 73.2% after the catalyst being used for three times. These results showed that the catalysts have promising viability in esterification for biodiesel production in industry.