Determination of Free Glycerol in Biodiesel by using PDA UV-Vis Spectrophotometer -Colorimetric method -

Biodiesel is the typical biofuel, made from vegetable and animal oil, and is currently used for diesel fuel car and heating, blended with diesel fuel or as a pure fuel. Recently, the need of biodiesel has rapidly increased as it is regarded as one of the alternative energies of coal oil. This is generally produced through the ester-transesterfication reaction by adding MeOH to triglyceride as shown in Figure 1 below. The product of the reaction is fatty acid methyl esters (FAME), which are known as biodiesel, and glycerol. As the co-product, glycerol, affects the quality of biodiesel, contents of glycerol are limited in the ASTM. (Total glycerol: below 0.24 %, free glycerol: below 0.02 %)