Analysis of the biodiesel production yield from waste frying oil

Abstract

This research sought to produce biodiesel from waste frying oil (WFO) from chicken grills by using chemical transesterification to evaluate quality conditions and the yield of the biodiesel obtained. For this, acid esterification and basic transesterification were applied under the following conditions: reaction temperature 60°C, catalyst concentration of 1% (m/m) KOH, oil:alcohol 1: 6 molar ratio, and two reaction times (55 and 70min) for the transesterification. The physicochemical properties of the raw material were analyzed (i.e., density, humidity, kinematic viscosity, fatty acid profile, acidity index, peroxides, and saponification) where the WFO showed high contents of oleic acid (42.45%) and palmitic acid (33.52%), which are fundamental for biodiesel production. Chemical transesterification under the conditions of 60°C, 1% KOH, and 70min obtained the best yield by presenting a high conversion percentage (96.15%) and an acid number of 1.33mmKOH/g, according to ASTM D6751 and EN 14214 international standards.