III International Conference

PP-III-15TRANSESTERIFICATION OF VEGETABLE OIL TO BIODIESEL OVERMgO-FUNCTIONALIZED MESOPOROUS CATALYSTSLi E., Rudolph V.Chemical Engineering Department, University of Queensland, QLD 4072, AustraliaE-mail: eugenal@cheque.uq.edu.auThis study compares the catalytic activity of MgO-functionalized mesoporous materials,synthesized using different: (i) silica supports (MCM-41, KIT-6 and SBA-15); (ii) precursorsalts (magnesium acetate and nitrate); and (iii) loading methods (impregnation and in-situcoating), in the transesterification of blended vegetable oil with ethanol. The yield of selectedesters (ethyl palmitate, stearate and oleate) was used as a marker to determine the most activeheterogeneous catalyst for biodiesel production. Effects of support material, precursor salt andloading method on the basicity and catalytic activity of the catalyst were analyzed.Recently, there has been an increased research activity directed at the development ofheterogeneous catalyst systems to produce biodiesel. Their benefits include simplification ofthe separation and purification of the reaction products, easy reuse of the catalyst in thereactor, reduced corrosion problems and possibly low sensitivity to free fatty acids and water.This study compares the catalytic activity of MgO-functionalized mesoporous materials,synthesized using different silica supports, precursor salts, and loading methods, in thetransesterification of blended vegetable oil with ethanol to produce biodiesel. Mesoporouscatalysts are chosen because their acidic/basic properties can be easily modified by varyingtheir surface groups and composition, they have uniform structures and high surface areas,which are ideal as catalysts for large organic molecules and guest-host chemical supports.Three types of mesoporous silica, namely MCM-41, KIT-6 and SBA-15, were preparedand subsequently impregnated with MgO using magnesium acetate. Another batch of SBA-15was loaded with MgO using magnesium acetate and nitrate via in-situ coating. Themorphology and basicity of the catalysts were characterized using XRD, N 2adsorption/desorption, CO 2 Chemisorption, and SEM techniques.The transesterification of vegetable oil was carried out in a batch reactor at 220 °C, withan oil-to-ethanol molar ratio of approximately 1:6, a reaction time of 5 hours, and a catalystamount of ~2 wt %. While the pure mesoporous silica showed little or no catalytic activity,calcined mesoporous supports loaded with MgO were found to be active as catalysts, amongwhich SBA-15 impregnated with MgO via magnesium acetate was the most effective. Theresulting yield of the selected esters ranged from 62 % to 96 % over the MgO-functionalizedcatalysts when compared to a complete homogeneous transesterification catalyzed by KOH496