Alumina/silica supported K2CO3 as a catalyst for biodiesel synthesis from sunflower oil.

The new type of catalyst for fatty acid methyl esters (FAME or biodiesel) synthesis with K(2)CO(3) as active component on alumina/silica support was synthesized using sol-gel method. Corresponding catalyst (xerogel) was prepared by 12h drying the wet gel in air at 300 degrees C, 600 degrees C or 1000 degrees C at atmospheric pressure. The catalysts activity in the methanolysis of sunflower oil was compared to the activity of the pure K(2)CO(3). The effects of various reaction variables on the yield of FAME were investigated. It was found that the temperature of 120 degrees C and methanol to oil molar ratio of 15:1, are optimal conditions for FAME synthesis with synthesized catalyst. Repeated use of same amount of catalyst indicated that effect of potassium leaching obviously existed leading to decrease of catalyst activity.