Kinetics of Biodiesel Production in Alkali Catalyzed Transesterification of Groundnut Oil

Abstract

Abstract. This article considers the kinetics of biodiesel production in alkali-catalyzed transesterification of groundnut oil using a batch reactor. The key chemical reactions involved were identified. The concentrations of the reactants and products with time were obtained experimentally. Their rates were modeled as nonlinear ordinary differential equations. The differential equations were integrated using the SCILAB ode function for given values of the six reaction rate constants, k1–k6. The residual between the measured and calculated values of the molal concentration was computed. The optimum value of each ki was determined by minimization of the sum of squares of the residuals using leastsq regression function. At 65∘C, their values were obtained as 4.4292, 0.0016, 2.0862, 0.7262, 0.0001, and 9.6358 l/(mol · s), respectively. The corresponding values at 70 °C were also obtained. The values are comparable to those reported in the literature for biodiesel production from other vegetable oils. The temperature dependence of the reaction rate constants was determined using the Arrhenius equation. The associated activation energy and the pre-exponential factor for each rate constant were determined. The results are useful for reactor design.