Synthesis of Ca-Doped Three-Dimensionally Ordered Macroporous Catalysts for Transesterification

Abstract

The novel three-dimensionally ordered macroporous (3DOM) CaO/SiO2, 3DOM CaO/Al2O3, and 3DOM Ca12Al14O32Cl2 catalysts for biodiesel transesterification were prepared by sol-gel method. The 3DOM catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The hierarchical porous structure was achieved; however, only 3DOM CaO/Al2O3 and 3DOM Ca12Al14O32Cl2 catalysts were used for transesterification due to high amount of active CaO. Various parameters such as methanol to oil molar ratio, catalyst concentration, reaction time, and their influence on the biodiesel production were studied. The result showed that 99.0% RPO conversion was achieved using the 3DOM Ca12Al14O33Cl2 as a catalyst under the optimal condition of 12 : 1 methanol to oil molar ratio and 6 wt.% catalyst with reaction time of 3 hours at 65°C.