Study On Preparation Of Biodiesel Catalyzed By Solid Acid And Base Catalysts

Biodiesel is one of green energy, it is becoming a hot new energy development. Thetraditional preparation of biodiesel was used homogeneous catalyst, but the process wascomplex in post-processing. The solid acid catalyst was easily separated from biodiesel andthe reaction is less pollution to the environment. The solid catalyst can overcome thedeficiency of homogeneous catalyst, so people began to look for the solid catalyst which hasthe advantage of low cost, mild reactivity conditions, circular use feasibility. The solidcatalyst CaO/Al₂O₃and Li₂O/CaO were easily separated from biodiesel in the end of thereaction and these solid catalyst were mild reactivity conditions. In this paper, the solidcatalyst CaO/Al₂O₃and Li₂O/CaO were prepared and then applied to the preparation ofbiodiesel. The main conclusions were as follows:CaO/Al₂O₃catalyst was prepared by impregnation method and the conditions ofpreparing catalyst were the amount of CaO loaded was25%, calcination temperature700℃,calcination time5h. On this basis, The conversion of91.5%was achieved using a12:1methanol to oil molar ratio at65℃for5h and6wt%catalyst.Li₂O/CaO catalyst was prepared by impregnation method and the conditions of preparingcatalyst were the amount of Li loaded was5%, calcination temperature600℃, calcinationtime5h. On this basis, The conversion of93.5%was achieved using a10:1methanol to oilmolar ratio at65℃for80min and4wt%catalyst.Study on the preparation of biodiesel reaction kinetics used NaOH as catalyst, Theresults show that the transesterification follows a2order kinetic equation. The reaction rateequations was-r_A=0.7034C₀^2.0249Study on the preparation of biodiesel reaction kinetics usedLi₂O/CaO as catalyst. The results show that the transesterification follows a1.4order kineticequation. The reaction rate equations were-r_A=0.0981C₀^1.46915,-r_A=0.0677C₀^1.35078under338K﹑328K. the activation energy of the reaction is34.19kJ/mol.