| As a renewable and green energy, Biodiesel has attracted considerable attention. Supercritical transesterification method has many advantages: faster reaction rate, higher conversion, simplier puration and so on. In this paper, the kinetics of the transesterification of rapeseed oil in supercritical methanol was investigated and the process was designed using simulation method.Effects of reaction temperature, molar ratio of methanol to rapeseed oil and reaction time on the yield of biodiesel were studied by means of orthogonal experiments. The order of their effectiveness to the yield of biodiesel was as follows: reaction temperature, molar ratio of methanol to rapeseed oil, reaction time. Under the optimal reaction conditions: reaction temperature 300℃, molar ratio of methanol to rapeseed oil 42:1, reaction time 20mins, the yield of biodiesel could reach 97.95%.Reaction kinetics of the transesterification of triolein, which was the model compound of rapeseed oil was studied. There are three stepwise reactions with intermediate formation of diolein and monoolein, the third reaction was determining step. The reaction rate constant of each reaction was obtained by using the method of parameter estimation, the order of three reaction rate constants was k2>k1>k3, These data were used to obtain the activation energy of each reaction, they were 223kJ/mol, 207kJ/mol and 154kJ/mol respectively.In addition, the process of biodiesel production using supercritical methanol was simulated by making use of the chemical engineering simulation software ProII. The UNIFAC model was used to calculate property data of triolein, diolein and monoolein, due to their importance in the process simulation. The thermodynamic models of NRTL and SRKM were applied to the process simulation. The simulation results showed that the selected thermodynamics models suited the system well and the design of the process were suitable, which could provided significant refrences for engineering design.
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