Optimization of Potassium Carbonate-based DES as Catalyst in the Production of Biodiesel via Transesterification

Abstract

Increasing energy demand necessitates the production of sustainable fuels, which can be in the form of bio-fuels. One of such bio-fuels is biodiesel, which is typically produced via transesterification. The development of homogeneous catalyst that is relatively easy to synthesize, cheap, reusable, and environmentally friendly, is a major issue in transesterification reaction. The use of Deep eutectic solvent (DES) as catalyst, is believed to be a significant step in the direction of attaining a sustainable bio-economy. In this study, deep eutectic solvent was synthesized from different mole ratios of K2CO3/glycerol. The synthesized DES was used as catalyst in the transesterification reaction to produce biodiesel from Jatropha curcas oil. Box-Behnken design (BBD) was used to determine the factors that significantly affect the biodiesel yield. Optimum fatty acid methyl ester (FAME) yield of 98.2845% was achieved at optimum conditions of 1:32.58 mole ratio of K2CO3/glycerol, 8.96% w/w concentration of DES, and 69.58 minutes. GC-MS analysis revealed that the produced biodiesel contained 98.87% ester content. The properties of the biodiesel produced were characterized and found to agree with those of ASTM D6751-12 standard. Thus, suggesting the synthesized DES is a promising catalyst in the transesterification reaction to produce biodiesel from Jatropha curcas oil.

Keywords

• deep eutectic solvent, fatty acid methyl ester, Jatropha curcas oil, potassium carbonate, transesterification