RETRACTION: RETRACTED: Study on the influence of Mg and catalytic activity of SAPO-34 on biodiesel production from rambutan seed oil (Retraction of 2019)

In this study, the effect of Mg impregnated into microporous SAPO-34 on catalytic activity was investigated for biodiesel production from rambutan seed oil. The modification of the support was conducted by a wet impregnation process, and the modified catalyst was calcined at 500 degrees C for 3 h and characterized by X-ray diffraction (XRD), N-2 physisorption and TPD-NH3 for crystal phase, textural properties and acidic behavior, respectively. The transesterification process was conducted with rambutan seed oil to test the effectiveness of the catalyst and to investigate the effect of Mg loading on the surface of the parent support, SAPO-34. The presence of Mg was confirmed by the XRD results. The N-2 physisorption results showed a decrease in surface area from 508 to 373 m(2)/g after the incorporation of a high percentage of Mg, while acidic strength decreased with increased Mg loading. The optimization results and conditions that achieved the highest fatty acid methyl ester (FAME) yield of 90.7 were 15 wt% Mg loading, 80 degrees C reaction temperature, 3.0 wt% catalyst loading, 15:1 methanol:oil molar ratio and 100 min reaction time. A drop in catalyst activity (15 wt% Mg/SAPO-34) of only about 4% was observed during the reusability studies after three consecutive runs. This makes 15 wt% Mg/SAPO-34 a suitable catalyst for transesterification.