Abstract
The relatively poor cold-flow properties of monoalkyl esters of vegetable oils and animal fats (biodiesel) present a major obstacle to their development as alternative fuels and extenders for combustion in direct injection compressionignition (diesel) engines. In this work, differential scanning calorimetry (DSC) heating and cooling curves of methyl soyate (SME), methyl tallowate (TME), SME/TME admixtures, and winterized SME were analyzed. Completion of melt, crystallization onset (Onset), and other temperatures corresponding to melting and freezing peaks were correlated to predict cloud point (CP), pour point (PP), cold filter plugging point (CFPP), and low-temperature flow test (LTFT) data. Effects of treating methyl esters with cold-flow improvers were examined. Low-temperature flow properties of biodiesel may be accurately inferred from subambient DSC analyses of high-melting or freezing (β-form) peaks. The temperature of maximal heat flow for freezing peaks gave the best accuracy for predicting CP, PP, and CFPP, while freezing point gave the best accuracy for predicting LTFT. Onset also gave good correlations with respect to predicting PP, CFPP, and LTFT. Cooling scan parameters were more reliable than heating scan parameters.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Chandler, J.E., F.G. Horneck, and G.I. Brown, The Effect of Cold Flow Additives on Low-Temperature Operability of Diesel Fuels, in SAE Technical Paper Series Paper No. 922186, Society of Automotive Engineers, Warrendale, PA, 1992.
Lewtas, K., R.D. Tack, D.H.M. Beiny, and J.W. Mullin, Wax Crystallization in Diesel Fuel: Habit Modification and the Growth of n-Alkane Crystals, in Advances in Industrial Crystallization, edited by J. Garside, R.J. Davey, and A.G. Jones, Butterworth-Heineman, Oxford, 1991, pp. 166–179.
Dunn, R.O., and M.O. Bagby, Low-Temperature Properties of Triglyceride-Based Diesel Fuels: Transesterified Methyl Esters and Petroleum Middle Distillate/Ester Blends, J. Am. Oil Chem. Soc. 72:895–904 (1995).
Owen, K., and T. Coley, Diesel Fuel Low-Temperature Characteristics, in Automotive Fuels Handbook, Society of Automotive Engineers, Warrendale, PA, 1990, pp. 353–403.
McMillan, M.L., and E.G. Barry, Fuel and Vehicle Effects on Low-Temperature Operation of Diesel Vehicles—The 1981 CRC Field Test, in SAE Technical Paper Series Paper No. 830594, Society of Automotive Engineers, Warrendale, PA, 1983.
Dunn, R.O., and M.O. Bagby, Low-Temperature Filterability Properties of Alternative Diesel Fuels from Vegetable Oils, Proceedings of the Third Liquid Fuels Conference: Liquid Fuels and Industrial Products from Renewable Resources, edited by J.S. Cundiff, E.E. Garett, C. Hansen, C. Peterson, M.A. Sanderson, H. Shapouri, and D.L. Van Dyne, American Society of Agricultural Engineers, St. Joseph, MI, 1996, pp. 95–103.
Dunn, R.O., M.W. Shockley, and M.O. Bagby, Improving the Low-Temperature Properties of Alternative Diesel Fuels: Vegetable Oil-Derived Methyl Esters, J. Am. Oil Chem. Soc. 73:1719–1728 (1996).
Lee, I., L.A. Johnson, and E.G. Hammond, Reducing the Crystallization Temperature of Biodiesel by Winterizing Methyl Soyate, Ibid. 73:631–636 (1996).
Dunn, R.O., M.W. Shockley, and M.O. Bagby, Winterized Methyl Esters from Soybean Oil: An Alternative Diesel Fuel with Improved Low-Temperature Flow Properties, in SAE Special Publication SP-1274: State of Alternative Fuel Technologies—1997, Paper No. 971682, Society of Automotive Engineers, Warrendale, PA, 1997, pp. 133–142.
Heino, E.-L., Determination of Cloud Point for Petroleum Middle Distillates by Differential Scanning Calorimetry, Thermochim. Acta 114:125–130 (1987).
Claudy, P., J.-M. Létoffé, B. Neff, and B. Damin, Diesel Fuels: Determination of Onset Crystallization Temperature, Pour Point and Filter Plugging Point by Differential Scanning Calorimetry. Correlation with Standard Test Methods, Fuel 65:861–864 (1986).
Noel, F., Thermal Analysis of Lubricating Oils, Thermochim. Acta 4:377–392 (1972).
Redelius, P., The Use of DSC in Predicting Low Temperature Behaviour of Mineral Oil Products, Ibid.:327–330 (1985).
ASTM D2500: Standard Test Method for Cloud Point of Petroleum Oils, in Annual Book of ASTM Standards, Vol. 05.02, American Society for Testing and Materials, Philadelphia, PA, 1991, pp. 268–270.
ASTM D97: Standard Test Method for Pour Point of Petroleum Oils, in Ibid., Vol. 05.01, American Society for Testing and Materials, Philadelphia, PA, 1993, pp. 85–88.
ASTM D4539: Standard Test Method for Filterability of Diesel Fuels by Low-Temperature Flow Test (LTFT), in Ibid., Vol. 05.03, American Society for Testing and Materials, Philadelphia, PA, 1991, pp. 446–450.
IP 309: Cold Filter Plugging Point of Distillate Fuels, in IP Standard Methods for Analysis and Testing of Petroleum and Related Products, The Institute of Petroleum, London, 1991.
Cebula, D.J., and K.W. Smith, Differential Scanning Calorimetry of Confectionery Fats. Pure Triglycerides: Effects of Cooling Rate and Heating Rate Variation, J. Am. Oil Chem. Soc. 68:591–595 (1991).
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Dunn, R.O. Thermal analysis of alternative diesel fuels from vegetable oils. J Amer Oil Chem Soc 76, 109–115 (1999). https://doi.org/10.1007/s11746-999-0056-9
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11746-999-0056-9