혼합금속산화물 촉매 및 마이크로파를 이용한 바이오디젤 합성

Abstract

In this study, synthesis of biodiesel from oleic acid using the heterogeneous acid catalyst and microwave has been investigated. To complement the drawback of homogeneous catalyst. Heterogeneous acid catalyst were used for the synthesis of biodiesel. The sulfated titanium oxide (SO42-/TiO2) and sulfated tin oxide (SO42-/SnO2) were selected as heterogeneous acid catalysts because sulfated metal oxides are known to be highly acidic solids. The catalysts were synthesized by sol-gel method. The preparation of biodiesel using a scientific microwave apparatus is known to be one of fast and easy routes to the valuable biofuel with advantages of a short reaction time and low reaction temperature. Bismuth molybdenum oxide is used to microwave effect. The catalysts were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Field Emission Scanning Electron Microscope (FE-SEM) and Temperature Programmed Desorption (TPD). The methyl ester contents was investigated by Gas Chromatography(GC) analysis. The SO42-/TiO2 and SO42-/SnO2 were found to be the effective catalysts in esterification of unsaturated fatty acid to methyl esters. The optimization of reaction parameters with the most active SO42-/TiO2 catalyst indicated that at reaction temperature 65℃, 1:20 oil to methanol molar ratio, 5wt.%_oil catalysts loading, and reaction time of 3h, a maximum ester yield of 97.69% could be obtained. In the case of SO42-/SnO2 catalyst at reaction temperature 60℃ 1:20 oil to methanol molar ratio, 3wt.%_oil catalysts loading, and reaction time of 2h, a maximum ester yield of 96.44% could be obtained. It was revealed that microwave heating is more efficient than conventional heating to prepare biodiesel. Therefore it may be possible for the microwave heating to take advantage of great rate accelerations to reduce the reaction time.