Study On Solid Base Catalyts For Biodiesel Production From Transesterification Reaction

The world has been confronted with energetic and environmental crises caused by depletion of conventional fuels.Biodiesel is promising sustainable and is expected as a part of renewable and environmentally friendly substitute for tranditional fossil diesel.Currently,biodiesel is produced via transesterification of triglycerides with alcohol using homogeneous catalysts.However,removal of the catalyst after the reaction is a major problem for a large amount of wastewater was generated when separating the catalyst and products.Hence,a plenty variety of heterogeneous catalysts have been used for biodiesel production.Due to the higher catalytic activity of basic catalysts over acid catalysts,they have been preferably studied.The most commonly used preparation methods of basic catalysts including physical mixing,impregnation,co-precipitation and sol-gel method.Nevertheless,these methods are rather cost expensive and difficult for large-scale industrialization because of its complicated synthesizing steps.Therefore,is has important theoretical and pratical significance to find ideas and development of cost effective simple-step method for preporation of catalyst.?1?A series of Ca/Zr mixed oxide catalysts were prepared by three different methods and used in the transesterification for biodiesel production.The resulting processed materials were characterized using TG-DSC,N2-adsorption,XRD,SEM CO₂-TPO and XPS to elucidate their composition,morphology and basic properties.It was found that the birch-template method was beneficial for the improvement of the pore structure and the dispersion of basic sites.The highest biodiesel yield reaches 91% over C0.3Z?T?under the optimal reaction conditions of catalyst mass fraction 8%,72:1 molar ratio of methanol to rapeseed oil,reaction temperature 100 oC and reaction time 6 h.No obvious deactivation was found after 5 reaction cycles over C0.3Z?T?.?2?Zn/Al/Cr complex mixed oxide catalysts were prepared by three different methods and used in the transesterification for biodiesel production.The characterization results showed that the sample Z₂AC₁?T?exhibited excellent pore structure and basic properties.The highest biodiesel yield reaches 92% over Z2AC1?T?under the optimal reaction conditions of catalyst mass fraction 10%,60:1 molar ratio of methanol to rapeseed oil,reaction temperature 100 oC and reaction time 6 h.