The Study Of The Production Of Biodiesel By Transesterification Of Rapeseed Oil With Solid Base Catalyst

Biodiesel produced by the transesterification of natural oil with methanol,ethanol or other short-chain alcolols is an environmental benefits,biodegadable and nontoxic fuel.With a traditional homogeneous acid or base catalyst,the tansesterification products are difficult to be separated and the waste water from washing catalyst may pollute environment.Using a solid base catalyst can obtain pure product and avoid the problem of catalyst deposition.At the same time,the problem of long reaction time with solid acid catalyst is overcame.In this work,we select thulium oxide such as La₂O₃,Sm₂O₃,Y₂O₃ and Eu₂O₃ as carriers and loaded with different amount of KF as solid base catalysts.Catalysts were calcined at 873 K for 4 hours.X-ray diffraction patterns of the catalysts revealed that some new substances were created.The strength and amount of basic sites on the catalyst surface was measured by temperature programmed desorption of carbon dioxide (CO₂-TPD).CO₂-TPD profiles showed that the density and amount of basic sites on the surface of the catalyst changing with the loading amount of KF.The catalytic activity of the catalyst was associated with the alkalescence on the surface of the catalyst.The effect of the loading amount of KF,methanol to oil molar ratio,catalyst amount and the reaction time on the transesterification process of rapeseed oil with methanol was investigated.Under a condition of atmospheric pressure,methanol to oil molar ratio of 12:1,338 K and catalyst amount of 3%(wt.Of catalyst/wt.Of oil),used 15%KF/La₂O₃ could get a reaction conversion of oil reached about 94.3%,used 15 %KF/Sm₂O₃ could get a reaction conversion of oil reached about 95.1%,used 15% KF/Eu₂O₃ could get a reaction conversion of oil reached about 91.2%,...