Preparation of biodiesel by ultrasonic assisted esterification of Tall oil fatty acid over solid acid catalyst

Biodiesel was prepared by the esterification of Tall oil fatty acid (TOFA) with methanol over the cation exchange resin solid acid catalyst under the assistance of ultrasonic. The preparation process and the characteristic of the biodiesel obtained were investigated; a kinetic model was built. The results showed that the ultrasonic irradiation can effectively improve the yield of biodiesel. The optimum processing condition is 65℃, reaction time of 1h, mol ratio of methanol/TOFA being 10, dehydrating agent quantity of 6% (based on TOFA) and catalyst amount of 40% (based on TOFA); under such a condition, the biodiesel yield reaches 90.0%. The kinetic parameters for the ultrasonic assisted esterification are obtained, which can well explain process regulation. Current process is economical to prepare biodiesel on the market, because cheap TOFA from black liquor is used as the raw material; it may provide a potential way to efficiently utilize TOFA.