The Studies On Transesterification Of Soybean Oil Catalysed By New Multiphase Composite Metal Oxide

In the paper, CaO-MoO₃-SBA-15, aminopropyl silica gel and CaO-SnO2solid catalystswere prepared by different methods followed by calcined and tested for soybean oil withmethanol transesterification reaction. The reaction conditions including catalyst amount,methanol/oil mole ratio, reaction time, free fatty acid content and moisture content, and thepreparation conditions and preparation method, were studied to value how they affected thesoybean oil conversions. The methods of SEM, FIT-IR, XRD，DTA-TG and XPS wereemployed to characterize the solid catalysts. The relationship between the catalystperformance and the structure was studied to explore the catalytic mechanism and find the theroot of activityThe experimental results showed that, for CaO-MoO₃-SBA-15solid catalyst, theappreciate conditions were: methanol/oil mole ratio50:1, catalyst amount6wt.%, reactiontime50h,40%of the active component loading, calcination temperature823K, and thesoybean oil conversion could reach82.2%under the above conditions. For aminopropyl silicagel solid catalyst, the appreciate conditions were: methanol/oil mole ratio30:1, catalystamount8wt.%, reaction time6h, reaction temperature423K, and the conversion could reach94.8%under the above conditions.For CaO-SnO2solid catalyst, the appreciate conditionswere: methanol/oil mole ratio12:1, catalyst amount8wt.%, reaction time4h, Ca/Sn molarratio of4, calcination temperature973K, and the conversion could reach87.5%under theabove conditions.The SEM, IR, XRD,TG-DTA and XPS characterized results showed that catalyticactivity of CaO-MoO₃-SBA-15, aminopropyl silica gel and CaO-SnO2was relative to thepresence modality of Ca, Mo and Sn activity center closey. The excessively enhancingcalcination temperature or increasing Ca, Mo and Sn content will result in lots of CaO, MoO₃and SnO2crystallites congregating on carrier, and consequently led to the catalytic activitydeclining. All catalysts showed good stability of soybean oil catalyzed transesterification.