Modified Sulfonated Glucose-Catalyzed Esterification of Palm Fatty Acid Distillate: Kinetics and Fuel Properties

Abstract

The employment of sugar acid catalysts for biodiesel synthesis from non-edible palm fatty acid distillate (PFAD) has received huge research interest in recent times by reason of their stability and high catalytic performance. Notwithstanding, the need to extend research on the kinetic characteristics of these heterogeneous catalysts is important in order to understand their reaction mechanisms. The present investigation deals with the kinetics for the esterification of PFAD by means of modified sulfonated carbonized glucose catalyst to biodiesel in a three necked conventional reflux batch reactor. The efficient catalyst was synthesized by sulfonation of incomplete carbonized glucose. The pseudo-homogeneous first and second order (equimolar) mechanism was utilized to interpret the data at optimum operating conditions of 10:1 molar fraction of methanol to PFAD, 4 h time of reaction and 4 wt.% quantity of catalyst at varying reaction temperature of 50-65°C. Furthermore, some important properties of the PFAD biodiesel produced were assessed utilizing ASTM methods. The experimental data best fitted the bimolecular model (equimolar) second order model. The activation energy was calculated to be 55.08 kJmol-1 which indicates that the catalyst was very active in the esterification of the PFAD to biodiesel. Most of the measured fuel properties of the PFAD biodiesel were comparable with the ASTM standards.