Gas Chromatographic Determination of Glycerol and Triglycerides in Biodiesel from Jatropha and Castor Vegetable Oils

Abstract:

Monoacylglycerols and diacylglycerols are intermediate compounds in biodiesel which result from incomplete transesterification reaction during biodiesel production. Traces of free glycerine and partially reacted triacylglycerols are also found in biodiesel. These contaminants cause serious operational problems in engines, such as engine deposits, filter plugging, and emissions of hazardous gasses. Increased levels of these contaminants in biodiesel compromise quality which is vital for commercialisation of this product. In this work, levels of free glycerine and total glycerine in jatropha methyl ester (JME) and castor methyl ester (CME) were determined using gas chromatography (GC) equipment. Amounts of free and total glycerine in JME and CME were generally high compared to the ASTM D6751 and EN14214 recommended values. Free glycerine from JME was 0.1% wt compared to 0.02% wt (ASTM D6751) and 0.01% wt (EN14214) values whereas the total glycerine from JME was 2.96% wt compared to 0.24 %wt (ASTM D6751) and 0.21% wt (EN14214). These discrepancies could have resulted from insufficient purification of the product and incomplete conversion or due to the high temperature associated with GC analysis that might have caused pyrolysis or thermal degradation of certain lipid components. Castor methyl ester free glycerine was 0.14% wt while total glycerine was 13.21% wt. This can still be explained by the same reasons given for JME. Thermal decomposition of lipid components in a GC could have interfered with the summative mass closure calculations that were done to determine the total composition of the biomass.

• Periodical: Advanced Materials Research (Volume 824)
• Pages: 436-443
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.824.436
• Online since: September 2013
• Authors: A. Okullo, P. Ogwok, A.K. Temu, J.W. Ntalikwa
• Keywords: Castor Methyl Ester, Free Glycerine, GC Analysis, Jatropha Methyl Ester, Total Glycerine

References

[1] G. Knothe Analytical Methods Used in the Production and Fuel Quality Assessment of Biodiesel, Transaction of the American Society of Agricultural Engineers. 44 (2001) 193-200.

[2] M. Canakci and H. Sanli, Biodiesel production from various feedstock and their effects on the fuel properties, Journal of Industrial Microbiology Technology. 35 (2008) 431-441.

DOI: 10.1007/s10295-008-0337-6

[3] A.K. Agarwal, S. Sinha, and S. Garg, Biodiesel development from rice bran oil: Transesterification process optimization and fuel characterization, Energy Conversion and Management. 49 (2008) 1248-1257.

DOI: 10.1016/j.enconman.2007.08.010

[4] A. Demirbas, Biodiesel production from vegetable oils by supercritical methanol, Journal of Scientific and Industrial Research. 64 (2005) 858-865.

[5] P.S. Bisen and B.S. Sanodiya, Biodiesel production with special emphasis on lipase-catalyzed transesterification, Biotechnology Letters. 32 (2010) 1019–1030.

DOI: 10.1007/s10529-010-0275-z

[6] A. Ghaly, D. Dave, M. Brooks and S. Budge, Production of Biodiesel by Enzymatic Transesterification, Review: American Journal of Biochemistry and Biotechnology. 6 (2010) 54-76.

DOI: 10.3844/ajbbsp.2010.54.76

[7] Y. Liu, Y. Yan, F. Hu, A. Yao, Z. Wang and F. Wei, Transesterification for Biodiesel Production Catalyzed by Combined Lipases, Optimization and Kinetics, AIChE Journal. 56 (2010b) 1659–1665.

DOI: 10.1002/aic.12090

[8] G. Kumar, D. Kumar, S. Singh, S. Kothari, S. Bhatt and C. Singh, Continuous Low Cost Transesterification Process for the Production of Coconut Biodiesel, Energies. 3 (2010) 43-56.

DOI: 10.3390/en3010043

[9] S.P. Singh and D. Singh, Biodiesel Production through the use of different sources and Characterization of oils and their esters as the substitute of diesel, A review. Renewable and Sustainable Energy Reviews. 14. (2010)200-216.

DOI: 10.1016/j.rser.2009.07.017

[10] P. Bondioli and D. B. Laura, An alternative spectrophotometric method for the determination of free glycerol in biodiesel, European Journal of Lipid Technology. 107 (2005) 153-157.

DOI: 10.1002/ejlt.200401054

[11] G. Knothe, Monitoring a Progressing Transesterification Reaction by Fiber-Optic Near Infrared Spectroscopy with Correlation to 1H Nuclear Magnetic Resonance, Spectroscopy. 77 (2000) 489–493.

DOI: 10.1007/s11746-000-0078-5

[12] G. Knothe, Analytical Methods for Biodiesel, AOCS Press. (2005) 62-75.

[13] B.C. Plank, M. Lechner and L. Eberhard, Determination of acylglycerols in vegetable oil methyl esters by on-line normal phase LC-GC, Journal of High Resolution Chromatography. 20 (1997) 581-585.

DOI: 10.1002/jhrc.1240201103

[14] H.D. Isengard and M. Hein, Determination of underivated fatty acids by HPLC, Z Lebensm Unters Forsch A. 204 (1997) 420-424.

DOI: 10.1007/s002170050105

[15] M. Mittelbatch (1996), Diesel Fuel Derived from Vegetable Oils, VI: Specifications and Quality Control of Biodiesel: Bioresource Technology. 56 (1996) 7-11.

DOI: 10.1016/0960-8524(95)00172-7

[16] T. A. Foglia, K. C Jones, A. Nunez, J. G. Phillips and M. Mittelbach, Comparison of Chromatographic Methods for the Determination of Bound Glycerol in Biodiesel, Chromatographia. 60 (2004) 305-311.

DOI: 10.1365/s10337-004-0372-z

[17] R. W. Heiden, Analytical Methodologies for the Determination of Biodiesel Ester Purity Determination of Total Methyl Esters: Final NBB Report Lancaster, CONTRACT #: 520320-l 27th February, (1996).

[18] A. Okullo, A.K. Temu, P. Ogwok and J.W. Ntalikwa, Physico-Chemical Properties of Biodiesel from Jatropha and Castor oils, International Journal of Renewable Energy Research. 2 (2012) 379-384.

DOI: 10.4028/www.scientific.net/amr.824.436

[19] B. Freedman, E. H. Pryde and T.L. Mounts, Variables Affecting the Yields of Fatty Esters from Transesterified Vegetable Oils: JAOCS 61 (1984) 1638-1643.

DOI: 10.1007/bf02541649

[20] C. Plank and E. Lorbeer, Simultaneous determination of glycerol, and mono-, di- and triglycerides in vegetable oil methyl esters by capillary gas chromatography, Journal of Chromatography A. 697 (1995) 461-468.

DOI: 10.1016/0021-9673(94)00867-9

[21] C. Ortwin, M. Mittelbatch, S. Schober, J. Fisher and J. Haupt, Improvements needed for the biodiesel standard EN14214, Final Report for Lot 1 BIOScope. EC Project TREN/D2/44-LOT 1/S07. 54676. (2008).

[22] European Standard EN 14105, Fat and Oil derivatives-Fatty Acid Methyl Esters (FAME). Determination of free and total glycerol and mono-, di-, triglyceride contents, European Committee for Standardization. Ref. No. EN14105 (2011).

DOI: 10.3403/30207064

[23] European Biodiesel Board, EBB European Biodiesel Quality Report (EBBQR). Results of the nineth round of tests. Winter 2010/2011 Results. Boulevard Saint Michel, 34-1040 Bruxelles.

[24] C. Stavarache, M. Vinatoru, R. Nishimura and Y. Maeda, Fatty acids methyl esters from vegetable oil by means of ultrasonic energy, Ultrasonics Sonochemistry. 12 (2005) 367-372.

DOI: 10.1016/j.ultsonch.2004.04.001

[25] N. Lima da Silva, B. Benedito, M.F. Rubens and R.W. Maria, Biodiesel Production from Castor Oil: Optimization of Alkaline Ethanolysis, Energy Fuels. 23 (2009) 5636-5642.

DOI: 10.1021/ef900403j

[26] L. Canoira, J.G. García, A. Ramón, L. Magín and G.C. Reyes, Fatty acid methyl esters (FAMEs) from castor oil: Production process assessment and synergistic effects in its properties, Renewable Energy. 35 (2009) 208-217.

DOI: 10.1016/j.renene.2009.05.006