Biodiesel production using soybean oil catalyzed by K2O/Al2O3

Solid alkali catalyst was prepared with K
2
CO
3
immobilized on alumina by impregnation method. Represented with SEM, IR and BET techniques, the catalysts indicated relatively uniform particle size distribution with perfect particle surface area, pore volume and pore size. Soybean oil was catalyzed to investigate the catalysis characteristics. The results showed that the maximum conversion rate of 74.5% was obtained under the optimal reaction conditions: alcohol/oil molar ratio of 9∶1, 60°C, 5 hours, 3wt% catalyst. The catalyst could be reused with half-life of 7 times. The major components of biodiesel are mixture of C
17
and C
19
unsaturated fatty acid methyl esters.