Produção de ácidos graxos assistida por ultra-som para a produção de biodiesel

Abstract

Free-fatty acids were produced from residual soybean oil by saponification reaction followed by hydrolysis assisted by ultrasound. Response surface methodology was applied to evaluate the effects of the operating conditions: molar ratio of ethanol to oil, KOH concentration and temperature on the production of free fatty acid. A maximum conversion of 97.3% was obtained applying 0.3% of KOH and 3:1 molar ratio of ethanol and oil. The effect of temperature was not statistically significant. A comparative study was carried out between the traditional reflux technique and the ultrasound technique. The results showed a significant difference between the techniques, where the ultrasound conversion was 39.2% higher than the reaction carried out with the reflux technique. The free-fatty acids production applying ultrasound has produced high acidity products with the advantage of the use of low value raw materials.