Study On Non-carrier Solid Base Catalysts For Synthsis Of Biodiesel

To alleviate the energy shortage and environmental pollution problems, it is important and practical to search a renewable, environmental friendly alternative energy. People favour biodiesel as it is a new energy, because of its similar performance with petrochemical diesel and unique environmental protection, reproducible, security and other excellent performance. Heterogeneous catalytic transesterification has some merits, such as, mild reaction conditions, high conversion rate, reused catalyst, unpolluted and so on. It is advantageous to achieve continuous and large-scale production.The aim of this study is to examine soybean oil for biodiesel production, and to analyse the character of sorbean oil. The reaults show that acid value was 0.8071 mg/g, saponification value was 194.94 mg/g, moisture content was 0.01%, and the average molecular weigh of soybean oil was 866.90 g/mol. Calculation of glycerol yield was used to assess the catalytic activity of catalysts.Series of Non-carrier solid base catalyst of CaO/MgO, CaO/La2O3, CaO/ZrO2 were prepared successfully by frothing method of citric acid and co-precipitation method, the preparation conditions were optimized, the amount of base strength and alkali were determined by Hammett indicator method, and the catalytic properties of good catalysts were characterized by XRD and BET. The results show that the optimum conditions of the catalyst by frothing method were:molar ratio of Ca:Mg=1, calcination temperature were 750℃, calcinations time 6h, the catalyst particle size 160 mesh, and the optimization of co-precipitation method were:precipitant was NaOH, molar ratio of Ca:Mg=1, calcination temperature were 600℃, calcinations time 6h, the catalyst particle size 120 mesh. Through the characterization results of catelysts found that there is a certain relationship between the alkaline and catalytic activity, NMSCaMg catalyst has a strong alkaline, good crystal structure and larger surface area than others.A study for optimizing the reaction conditions for the transesterification of soybean oil by single factor experiment. Under the optimum conditions for NMSCaMgso of methanol to oil molar ratio of 10:1, catalyst dostage of 1.2wt%, reaction temperature of 60℃, and reaction time of 3.5h, the glycerol yield was 92.56%.87.15% yield of glycerol can be reached under the optimum reaction condition:molar ratio of methanol to oil 12:1, the amount of GCDCaMgso 1.5wt%, reaction temperature of 65℃, reaction time of 3.5h. The two types of catalysts both have good stability and repetition. Raw soybean oil and its products were characterized by infrared spectra, the drawing showed there was fatty acid methyl in the reaction products, and then it indicated that soybean oil was transformed into biodiesel successfully.