Hydrothermal treatment of SO4/TiO2 and TiO2/CaO as heterogeneous catalysts for the conversion of Jatropha oil into biodiesel

Abstract

The conversion of Jatropha oil into biodiesel has been conducted using the SO4/TiO2 acid and TiO2/CaO base catalysts via hydrothermal treatment using an autoclave reactor. The acid catalyst was prepared with the sulfation process of TiO2 using H2SO4 (0.5; 0.8; 1.1; 1.4; 1.7 and 2 M). The base catalyst was initiated by dispersing TiO2 (1, 5, 10, 15, and 20 wt%) on CaO. The aims of this research were to obtain the catalyst with the highest acidity and basicity from SO4/TiO2 and TiO2/CaO catalysts, respectively. Afterward, apply them to the esterification to reduce the free fatty acid of Jatropha oil and the transesterification of the esterified of Jatropha oil into biodiesel. Among the SO4/TiO2 catalysts, the ST-2–400 catalyst exhibits an optimum total acidity of 6.93 mmol NH3/g. This catalyst was able to reduce the FFA level of Jatropha oil from 1.22% to 0.59% with catalyst weight of 3%, ratio oil to methanol of 1:15, and reaction time of 90 min. The optimum total basicity from TiO2/CaO catalysts was achieved by TC-20-800 with the total basicity of 28.67 mmol HCl/g. The conversion of esterified Jatropha oil into biodiesel was performed using 3% of TC-20–800 catalyst at 65 °C for 90 min. The TC-20–800 catalyst was able to produce biodiesel up to 79.68%.