BIODIESEL SYNTHESIS: CATALYZED BY PRETREATED VOLCANIC ASH

摘要

Biodiesel is a commercialized biofuel with increasing usage, but its production consumes considerable amount of caustic soda. Heterogenous catalysts have been investigated to replace or reduce the use of caustic soda, but most of these approaches arecostly and not practical enough for industrialization. This research used the volcanic ash emitted from Mountain Sakurajima (Kagoshima, Japan), and the porous nature of these particles provided a reaction field for effectively adsorbing sodium hydroxideand catalyzing the methanolysis of triglycerides. By the aids of sonication (40 kHz, 18.5 w/1), typically 2 g of the ash was washed and then soaked in a sodium hydroxide aqueous solution (10 M x 0.5 ml). After drying at 60 °C, the alkalized volcanic ashwas used to catalyze the transesterification reaction of 100 g of soy bean oil and 23 g of methanol at 65 °C for 6 hr. The use of sodium hydroxide was extensively reduced as compared with the conventional protocol. The unused resource, volcanic ash, was proven to be a low-cost and easily prepared catalyst for biodiesel synthesis.