Study On Biodiesel Preparation From Chinese Vegetable Tallow By Hydrodynamic Cavitation Technology

Biodiesel is an alternative, clean and renewable fuel. However, the high production costs retard its commercialization all over the world. Chinese vegetable tallow (CVT) from the fruit of Chinese tallow tree (CTT) has simple fatty acid composition, thus CVT is perfect for preparing biodiesel and other high add-valued by-products. In the present paper, a production technology to prepare biodiesel with CVT by hydrodynamic cavitation was established, and processing parameters were investigated and optimized. Futhermore, the add-valued chemicals, methyl palmitate (MP) with purity 99.75% and methyl oleate (MO) with purity 89.51% were gained from biodiesel by vacuum distillation.The effects of hydrodynamic cavitation on esterification and transesterification process were studied. The result indicated that the mixing of oil and methanol and reaction process could be intensified by hydrodynamic cavitation. Comparing to mechanical agitation, the equilibration time of hydrodynamic cavitation was shortend two times. The result also indicated that the reaction process of oil and methanol could be intensified to a greater extent by hydrodynamic cavitation with impinging stream. Comparing to mechanical agitation, the equilibration time was shortened three times.Futhermore, the effects of operation modes and usage of methanal on esterification and transesterification process were studied. The result indicated that the continuous operation of multistage hydrodynamic cavitation, in which material stood for 20min in reaction temperature after each stage, could reduce the energy consumption of cycling. And recycling of methanol & catalyst could reduce methanol & catalyst consumption. The results also indicated that the increase of methanol usage was good to the esterification and transesterification process, but the promotion would be level off with increase of the usage of methanol.The analyzing result showed that the quality of the obtained biodisel satisfied the requirement of China biodiesel standard (BD100). Hydrodynamic cavitation technology will have an extensive prospect because of its time and energy saving, simple equipment and convenience to industrialize.