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To ease the energy shortage and environmental pollution problems, to seek a renewable and environmentally friendly alternative energy has important practical significance. Biodiesel and petroleum diesel with similar performance, and unique environmental protection, regeneration, security, excellent performance, and become a highly favored people of the new energy. Heterogeneously catalyzed transesterification mild reaction conditions, high conversion rate, the catalyst can be reused, pollution, etc., is conducive to continuous, large-scale production is achieved. This study investigated soybean biodiesel analysis determined physicochemical properties of soybean oil, acid value of 0.8071mg / g, saponification value 194.94mg / g, water content 0.01%, calculated average molecular weight of soybean oil 866.90g/mol , and to determine the yield of glycerol evaluate catalytic activity. Citric acid were used foaming method and coprecipitation of calcium and magnesium, calcium lanthanum and calcium zirconium composite oxide non-load solid base catalyst, the catalyst preparation conditions were optimized; using Hammett indicator method for the determination of alkaline catalyst strength and alkali, and the use of XRD and BET on the catalytic properties of a good catalyst characterization. Experimental results show that the catalyst prepared by citrate optimum conditions: magnesium ratio of 1:1, the calcination temperature 750 ℃, baking time 6h, the catalyst particle size of 160 mesh; coprecipitation optimum preparation conditions: NaOH to precipitate agents, calcium magnesium ratio of 1:1, calcination temperature 600 ℃, roasting time 6h, catalyst particle size 120 mesh. Catalyst characterization results showed that the activity of a certain relationship with the alkali, and has a strong alkaline catalyst NMSCaMg, preferably crystalline structure, large specific surface area. Through single factor experiment preferred catalyst for the catalytic properties of biodiesel transesterification reaction conditions were optimized. Optimal reaction conditions: the NMSCaMg5o as catalyst, methanol to oil molar ratio of 10:1, the amount of catalyst 1.2wt%, reaction temperature 60 ℃, reaction time 3.5h, glycerol yield 92.56%; to GCDCaMg50 (NaOH precipitant) is catalyst, the molar ratio of methanol to oil 12:1 catalyst 1.5wt%, the reaction temperature is 65 ℃, reaction time 3.5h, the yield was 87.15% glycerol, and the types of catalysts have good repetition stability. And the infrared spectrum of raw materials soybean oil and its ester exchange reaction products were characterized to determine the reaction products in the generation of fatty acid methyl ester, soybean oil indicates successful transformants.
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