Synthesis and Characterization of Glycerol from Vegetable Oil

Aliay Idris Eghbili*¹, Bubker A. Bader², Bulgasem Y. Bulgasem3, Sumaya G. Fnaish⁴, Ibrahem Saad Ibrahem⁵ and Fawzi Farag Mohamed⁶

¹*Department of Chemistry, Faculty of Engineering Sciences, University of Bright Star, Brega, LIBYA. ²Department of Metallurgical and Materials Engineering, Faculty of Engineering, University of Ajdabia, LIBYA. 3Department of Medical Microbiology, Al-Maqrief Central Teaching Hospital, Ajdabiya, LIBYA. ⁴Department of Community Health, Faculty of Medicine, University of Ajdabiya, LIBYA. ⁵ʼ⁶Department of Biology, Faculty of Sciences, University of Ajdabiya, LIBYA.


Glycerol, also known as 1, 2, 3-propanetriol is a viscous colorless and odorless liquid that tastes sweet; it is derived from both petrochemical and natural raw materials by esterification. The transesterification reactions of two different vegetable oils (sunflower and palm oil) with methanol, using potassium hydroxide as catalyst, for the production of glycerol, were studied. The preparation of ester involved a two-step transesterification reaction that was accompanied by purification. Nuclear magnetic resonance and FITR were employed to detect the spectra of the glycerol’s and oils respectively. There was no much difference in the glycerol yield by the two oils in which 2.6% and 2.5% were obtained by the sunflower and palm oil respectively. The physicochemical properties of the glycerol produced by both oils showed no differences in the free fatty acid contents, density and acid value but saponification value of 256.4 mgKOH/g for sunflower oil and 216.3 mg KOH/g for palm oil; viscosity of 8.5cp for sunflower oil and 4.96cp for palm oil; yellow color for to 5.3 that of sunflower oil and dark brown for that of palm oil. The Fatty acid measured by fatty acid methyl ester (FAME) revealed that sunflower oil had a percentage area ranging from 1.3 to 5.32% with retention time of 5.6 to 10 minutes while palm oil fatty acids had a percentage area of 0.02 to 0.17% with a retention time of 8.1 to 14.5 minutes. This has shown that the oils can be good sources for the production of glycerol and biodiesel.

Keywords :Sunflower, Palm oil, Glycerol, Biodiesel, Saponification.