การเตรียมออกไซด์ผสมของแคลเซียม ซิงก์ และอะลูมิเนียมสำหรับเมทานอไลซิสของไตรกลีเซอไรด์ / วนิดา อินชนะ = Preparation of Ca, Zn and AI mixed oxides for methanolysis of triglycerides / Vanida Inchana
The present thesis investigated preparation of mixed oxides of Ca, Zn and Al as heterogeneous catalyst for methanolysis of triglycerides. The catalysts were prepared by co-precipitation of aqueous solution of the mixed metal nitrates in the presence of NH₄OH and ((NH₄)₂CO₃) after which the mixed oxides were attained by calcination at various temperatures. On the other hand, Ca/ZnAl catalysts were synthesized via incipient-wetness impregnation of Ca(NO₃)₂ over the calcined ZnAl LDHs followed by the thermal treatment. The catalysts were characterized by X-ray fluorescence spectroscopy (XRF), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric/differential thermal analysis (TG/DTA), scanning electron microscopy (SEM), CO2- pulse chemisorption analysis and N₂ adsorption-desorption measurement. The Ca/ZnAl-500 catalyst with the molar ratio of Ca to Zn of 0.75 that was calcined at 500°C for 2 h gave the highest content of methyl esters. The methanolysis of triolein and trilaurin at reaction temperature of 60°C, reaction time of 3 h, molar ratio of methanol to oil of 15 and amount of catalyst of 10 wt.% gave the highest content of methyl esters of 83.8 and 99.9 wt.%, respectively.
