Kinetics of palm oil ethanolysis

Abstract

The effect of temperature and catalyst concentration on palm oil ethanolysis using 0.2 to 1 wt% NaOH based on the mass of palm oil was studied at temperatures ranging from 60 to 80 °C, keeping constant the ethanol to oil molar ratio (6:1). A 100% conversion of palm oil and a 96% yield of FAEE (fatty acid ethyl ester) were obtained after 60 min of reaction with 1 wt% NaOH at 70 °C. The increase of temperature between 60 °C and 70 °C on palm oil ethanolysis enhanced the reaction rate, but increase it from 70 °C to 80 °C had the contrary effect. The effect of temperature was higher during the first ten minutes of reaction. Increase of catalyst concentration between 0.2 wt% and 0.5 wt% strongly promoted the yield to FAEE, although this effect was not observed with further increments in the catalyst concentration. A second order kinetic model that predicts the behavior of the intermediate products and the effect of temperature and catalyst concentration was proposed and validated by the Fisher–Snedecor test of unbiased variances. Kinetic model parameters of palm oil ethanolysis and methanolysis were compared and demonstrated similar behavior and orders of magnitude.