Preparation Of Biodiesel By Transesterification With Solid Acids As Catalysis

Energy sources crisis and environmental pollution accelerated the development of renewable and environmentally friendly alternative energy sources. However, the expensive cost of biodiesel restricts its usage and commercialized. Cheap raw material, saving energy. simplified technology and catalyst reusing etc. are the main methods to the decrease of biosiesel production cost.In this thesis, SO42-/TiO2-SiO2 was used as a solid acid catalyst to catalysis the transesterification between jatropha oil and methanol. It replaces the traditional liquid acid and alkali catalysts. The results of experiments showed that methyl ester of jatropha cottonseed oil fatty acids content could achieve 96.8% under the transesterification conditions of reaction temperature 110℃, methanoi/oil molar ratio 12:1, solid acid catalyst dosage 4%, mixing speed 600rpm, co-solvent hexane/methanol volume ratio 1:2, reaction time 3h. The fatty acid methyl ester content remained 95% after the solid acid catalyst was reused ten times. The fuel properties of jatropha biodiesel obtained met the national BD100 standard.Biodiesel was obtained through transesterification between cottonseed oil and methanol under microwave radiation, using S2O82-/Al2O3-ZrO2-La2O3 as a solid acid catalyst. It was showed that, under the transesterification conditions of microwave power 300W. reaction temperature 120℃, methanol/oil molar ratio 12:1, solid acid catalyst dosage 3%, reaction time 1.5h, methyl ester of cottonseed oil fatty acids content could achieve 95.2%. The fatty acid methyl ester content remained 90% after the solid acid catalyst was reused ten times. The experimental results indicated that the catalyst of S2O82-/Al2O3-ZrO2-La2O3 had a higher activity and stability under follow optimum preparation conditions of n(Al): n(Zr):n(La)=1:0.4:0.08, roasting temperature 550℃, roasting time 5 h.The fuel properties of jatropha biodiesel obtained met the national BD100 standard.