Catalytic transesterification of kapok seed oil by dual metal oxide (Na2O-K2O; MgO-CaO) impregnated active-natural mordenite under ultrasonic irradiation

Various solid base catalysts have been used for biodiesel production from different edible and non-edible vegetable oils. Hitherto, reports pertaining to dual-basic metal oxides onto an acidic support is very limited. Herein, we have conducted a novel study using Na2O-K2O and MgO-CaO impregnated into Active Natural Mordenite (ANM) as Na2O-K2O/ANM and MgO-CaO/ANM for kapok seed oil transesterification. The physicochemical properties of the as-synthesized catalysts were analyzed using XRD, XRF-He, SEM, AAS, acidity, and surface area. The results showed that the activation of natural mordenite could reduce impurities, increase acidic strength, and the surface area. A series of ratio on Na2O:K2O and MgO:CaO was fine-tuned to give the highest biodiesel production. The catalyst, Na2O-K2O/ANM, with a concentration of 50% and ratio of 1:1 showed the lowest acidity, 0.352 mmol/g, and gave the highest yield of 72.29%. The highest yield, 84.54%, was obtained from MgO-CaO/ANM (40%; 2:1), with the lowest acidity of 0.331 mmol/g. Biodiesel properties, from the transesterification of the kapok seed oil, were characterized by SNI 7182:2015 standards. The characteristics of synthesized biodiesel met the used standard, and in terms of reaction activity, it is found that the alkalinity level of the catalyst is more influential than its surface area.