The production of biodiesel from used cooking oil; characterization of key fuel properties of ethyl esters and diesel-biodiesel blends

Abstract

In this work, the transesterification process was adopted to convert used vegetable oil into biodiesel, while using KOH as catalyst. Ethyl ester was produced with mixed feedstock of various waste cooking oils that had a free fatty acids (FFA) content of 2.5%. The catalyst concentration of 1.25% w/w and ethanol to oil molar ratio of 6:1 were found to be optimum at a temperature of 343.15 K. The blending of petroleum diesel with produced ethyl ester was found to be more advantageous as the densities and kinematic viscosities of mixtures are slightly increased compared with the petroleum-diesel. Important fuel parameters such as viscosity, density, flash point, pour point and higher heating value (HHV) were characterized according to ASTM standards.