Biodiesel has been known as the alternative energy which can be used to replace the fossil fuel consumption. Utilization of non-edible oil received much attention due to increasing competition of edible-oil market which leads increasing of the price of edible oil and biodiesel production cost. The common way for biodiesel production is through catalyzed-transesterification, especially heterogeneous catalyzed-transesterification due to its advantages in product separation. This study was conducted using magnesium and calcium oxide as catalyst. Kapok seed oil was used as feedstock for biodiesel production. The catalysts of magnesium oxide/calcium oxide (MgO/CaO) were calcined at 950ᵒC for 5 h. The catalyst were prepared in various composition of MgO (0.5-2 wt.%) to determine the best catalyst composition. The transesterification was maintained in various temperature (50-70◦C) and reaction time (30-120 min) in batch reactor. The highest yield of 59.58% was reached for 0.5 wt.% of MgO composition in the catalyst. In the effect of temperature and reaction time study, the optimum condition for biodiesel production was achieved at temperature of 70oC for 75 minutes. Under this condition, the highest biodiesel yield of 55.22% was obtained.
