The Optimization of Conversion of Waste Edible Oil to Fatty Acid Methyl Esters in Homogeneous Media

Abstract

Conversion of waste edible oil to the fatty acid methyl esters was optimized using sulfuric acid as a catalyst for transesterification and esterification simultaneously, and adding tetrahydrofuran as a cosolvent for producing a homogeneous media. The optimized model was established by the response surface methodology. The optimum conditions were methanol/oil molar ratio of 21:1, 3.95% of sulphuric acid based on the oil mass, and reaction period of 3.3 h at 64°C in the presence of tetrahydrofuran, obtaining a fatty acid methyl esters yield of 98.2%. Further verification experiments confirmed the validity of the predicted model. The result suggested that the present work had a significantly lower reaction temperature and methanol/oil molar ratio by the addition of tetrahydrofuran to the reaction system.

Keywords:

• cosolvent
• fatty acid methyl ester
• optimum
• response surface methodology
• waste edible oil

Notes

^aNumbers in parentheses represent actual experimental amounts.