SYNTHESIS OF BIODIESEL USING SULFONATED LIGNOSULFONIC ACID

Abstract

This research aimed to synthesize the lignosulfonic acid catalyst from lignosulfonic acid sodium salt. The lignosulfonic acid catalyst was synthesized via two different methods, including ion exchange with amberlyst-15resin method (preparation of lignosulfonic acid as a homogeneous catalyst) and Phenol formaldehyde condensation and ion-exchange with sulfuric acid method (preparation of lignosulfonic acid as a heterogeneous catalyst). The synthesized lignosulfonic acid catalyst as a homogeneous and heterogeneous catalysts were characterized by Infrared spectroscopy (IR), Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) techniques. In this research, the various parameters such as molar ratio of oil to methanol, catalyst dosage and reaction time were studied in order to optimize the optimum condition of biodiesel synthesis. The results show that the best condition of biodiesel synthesis was 1:6 mole ratio of oil to methanol, 5 wt% of catalyst, 6 h of reaction time at 65oC. The percent conversion of biodiesel was 98%. In addition, this heterogeneous catalyst could be reused up to five times. Viscosity of biodiesel was observed at 4.38 cSt and acid value at 0.425 mg KOH/g, all of these values were in the range of biodiesel standard.