Kinetics study of balanites aegyptiaca oil transesterification for the production of biodiesel

Abstract

In this study, transesterification of Balanites aegyptiaca oil employing a homogeneous catalyst (NaOH) was conducted in a reactor with methanol. The transesterification reaction at 6:1 methanol to oil ratio with 1wt% catalyst was studied at 35^oC, 40^oC, 45^oC, 50^oC and 55^oC. An attempt is made to determine the rate of transesterification of Balanites oil by measuring the rate of formation of methyl oleate using GC-MS technique. The concentration of the product (m-oleate) will be monitored by measuring the peak area of GC-MS chromatogram. A kinetic model together with relevant parameters like reaction order, rate constants and Arrhenius parameters would be estimated. It was realized that, first order kinetic model applies with rate constants (k) of 1.41x10^-1, 1.38x10^-1, 3.2x10^-2, 1.28x10^-1 and 1.39x10^-1 moles/sec. for the transesterification process at the prescribed temperatures. A general decrease in the reaction rate with increase in temperature was observed. The transesterification process didn’t proceed in accordance with the Arrhenius equation. This means, although the kinetic model and rates of constants were determined, the activation energy (E) and the frequency factor (A) couldn’t be estimated for the process.

Keywords: Balanites oil, GC-MS technique, Kinetics, Quantitative determination and Conc-Time Data