Chiang Mai Journal of Science

An efficient, simple conversion of oils to biodiesel catalyzed by uncalcined disodium metasilicate granules (0.3 mm-1 mm) is reported. Under optimum reaction conditions of catalyst content of 9 wt.%; methanol to oil molar ratio of 9:1; reaction temperature of 65 ºC with a constant stirring of 200 rpm, many types of oils including waste cooking oil can be transesterified with methanol to biodiesel with a fatty acid methyl ester (FAME) yield over 97% in 40 min. The water contamination in oil of less than 4 wt.% has no effect on the activity of the catalyst. The catalyst can be easily removed from the reaction mixture by a simple filtration and can be reused several times with consistent results. The obtained biodiesel without any cleansing shows a high quality product in which fuel properties of the biodiesel congregate all ASTM and EN 14214 standards for biodiesel. Purification process with a cation-exchange resin efficiently removes all soluble ions to obtain high quality biodiesel product. Uncalcined disodium metasilicate granules showed excellent to be used as a low-cost, green, easy and high potential heterogeneous solid catalyst for biodiesel production.