Preparation And Characterization Of Solid Base Catalyst

Biodiesel demand is growing with the social development. China started late in biodiesel production, but the advantages is that our country have a lot of vegetable oil which provides a wealth of raw materials for this study. There are many methods to prepare biodiesel, such as homogeneous catalysis method, solid phase catalysis method and supercritical flow method. Currently, they use a homogeneous catalysis to prepare biodiesel in domestic and international, such as liquid acid and alkali as a catalyst. There are many disadvantages in that methods, such as corrosive equipment, post-processing more complex products, produce waste water which can pollute the environment. It is the reason that people want to find a environment-friendly, efficient and safe catalyst. The advantages of solid base catalyst are high selectivity, easy separation with the product, non-corrosive, recyclable and non-pollution. Make people pay more and more attention to research of solid alkali catalyst.In this paper, catalyst was prepared by hydrothermal method which added the surfactant (CTAB). Mixed oxides as a solid base was prepared by calcination. Catalyst was characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, CO2-TPD and the Hammett indicator method. The results show that the added amount of CTAB can control the growth morphology of hydrotalcite and nondestructive the structure of hydrotalcite interlayer. Hydrotalcite is hexagonal before added CTAB. When CTAB the addition of the critical micelle concentration, the morphology of hydrotalcite remains large hexagonal but overlapping and when hydrotalcite was rod-like growth CTAB the addition is greater than the critical micelle concentration. The calcined hydrotalcite used in the catalysis of soybean oil. Influence of reaction was studied which is methanol to oil molar ratio, catalyst concentration, reaction time and reaction temperature. The conversion of soybean oil reached 78.9% under optimum conditions.Al2O3 and NaY were used as the carrier respectively in this paper. Alkaline earth metal nitrate is precursors. Catalyst was prepared by the method that thermal decomposition and impregnated combined. Catalyst was characterized by means of X-ray diffraction, TEM, TG and the Hammett indicator method. Catalyst was applied to ester exchange reaction. The results showed that 26% CaO/Al2O3 is the best and capacity of the catalytic which is NaY as a carrier for the solid base is better.