Preparation Of The Heterogeneous Catalysts And Their Applications In Biodiesel Synthesis

Biodiesel（fatty acid methyl ester） as green energy in 21 century is widely used and researched by people around world. Now the main difficulty prohibiting the promotion of the biodiesel locates at the high cost and catalysts select. Not only the traditional plant oil, the wast cook oil also is the important sours of the biodiesel. The wast cook oil can cut down the production cost but it contains too much free fatty acid. In present production process, NaOH and H₂SO₄ are the common catalysts, but NaOH will limits the raw material sours, and H₂SO₄ will affect the quality of the final production. On the other hands, the use of homogeneous catalysts relaying on water washing process to remove the catalyst which would cause the pollution and add the production cost.In this paper three alkaline catalyst（Fe₃O₄@Na₂MoO₄; Ca（CH₃O）₂; Ca（C₃H₇O₃）₂） and an acid catalyst（Fe₃O₄@Si O₂@Fe₂（SO₄）₃） were synthesised. For improving the catalyst separation character, the active material were loaded on magnetic nuclei, then separating the catalyst by magnet.In paper the catalyst was characted by FT-IR, particle size analysis, XRD analysis, SEM analysis, BET nitrogen adsorption, TG-DTA thermal analysis. And the best reaction environments were studied.The optimum conditions of magnetic sodium molybdate was 3% catalyst load, 40:1methanol/oil molar ratio, reaction temperature 100℃, the reaction time 2.5 h, the final conversion rate over 97%. Methanol calcium organic catalysts highest conversion could be got at 1% catalyst load, 12:1 methanol/oil molar ratio, reaction temperature 65℃, the reaction time 3 h, the final conversion rate over 97%. And Glycerin calcium organic catalysts highest conversion could be got at 2% catalyst load, 20:1 methanol/oil molar ratio, reaction temperature 65℃, the reaction time 3 h, the final conversion rate over 97%. Used as the catalyst of esterification reaction, magnetic ferric sulfate catalyst could got the highest conversion at 4% catalyst load, 25:1 methanol/oil molar ratio, reaction temperature 95℃, the reaction time 6 h, the final conversion rate over 94%.Otherwise, the influence of different sours on the biodiesel quality was studied. Soybean oil fatty acid methyl ester, sunflower seed oil fatty acid methyl ester, rapeseed oil fatty acidmethyl ester and wast cook oil fatty acid methyl ester were synthesised, and wast cook oil fatty acid methyl ester was refined by urea inclusion. Then the quality of this series biodiesel were compared for researching the biodiesel practical value.