Synthesis of biodiesel using KOH/Borax as suitable mixed catalyst via transesterification of waste sesame oil

The catalytic activity of KOH/borax as homogeneous mixed catalyst was evaluated for the synthesis of biodiesel via transesterification of sesame oil extracted from waste sesame seeds with n-hexane. The effects of catalyst loading، methanol to oil ratio، temperature and reaction time in transesterification were investigated. The highest yield of 87% for biodiesel production was obtained at optimized conditions including 0. 4 wt. % KOH and 10 wt. % Na2B4O7. 10H2O of mixed catalyst loadings، methanol to oil molar ratio of 8:1، reaction time of 2. 5 h and reaction temperature of 65 ˚C.