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Moray S. Stark,* Max Smethurst and Alexandra Neal

Degradation of Methyl Ester Analogues of Vegetable Oils at Elevated Temperatures. STLE 2006: Calgary 7 th - 11 th May 2006. Moray S. Stark,* Max Smethurst and Alexandra Neal Department of Chemistry, University of York, York YO10 5DD, UK. Department of Chemistry.

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Moray S. Stark,* Max Smethurst and Alexandra Neal

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  1. Degradation of Methyl Ester Analogues of Vegetable Oils at Elevated Temperatures STLE 2006: Calgary 7th- 11th May 2006 Moray S. Stark,* Max Smethurstand Alexandra Neal Department of Chemistry, University of York, York YO10 5DD, UK Department of Chemistry

  2. Degradation of Methyl Ester Analogues of Vegetable Oils at Elevated Temperatures STLE 2006: Calgary 7th- 11th May 2006 Moray S. Stark,* Max Smethurstand Alexandra Neal Department of Chemistry, University of York, York YO10 5DD, UK mss1@york.ac.uk www.york.ac.uk/res/gkg

  3. Degradation of Methyl Ester Analogues of Vegetable Oils at Elevated Temperatures • Degradation of Diesel Biofuels • In the Sump • In Fuel Lines • During Storage • Models of Degradation of Vegetable Oil Based Lubricants • As Analogues for the Oxidation of Alkenes • Formed by Aldol Condensation of Aldehydes Department of Chemistry

  4. Oxidation of Methyl Esters • Derived From Common Commercial Crop Oils Methyl Palmate(e.g. Palm Oil) (Methyl Hexadecanoate) Methyl Stearate (Methyl Octadecanoate) Methyl Oleate(e.g. Olive Oil) (methyl cis-9-octadecanoate) Methyl Linoleate(e.g. Soya Oil) (Methyl cis,cis-9,12-Octadecadienoate) Department of Chemistry

  5. Oxidation of Methyl Esters • Derived From Common Commercial Crop Oils Methyl Palmate(e.g. Palm Oil) (Methyl Hexadecanoate) Methyl Stearate (Methyl Octadecanoate) Methyl Oleate(e.g. Olive Oil) (methyl cis-9-octadecanoate) Methyl Linoleate(e.g. Soya Oil) (Methyl cis,cis-9,12-Octadecadienoate) Department of Chemistry

  6. Bench-Top Reactors Oxidation Conditions Sealed Reactor Initial pressure: 1000 mbar O2 Temperature: 130 ºC – 190 ºC Sampling: Throughout the reaction 10 sec – 10 hours Department of Chemistry

  7. Traditional Alkane Oxidation Mechanism Department of Chemistry

  8. Traditional Alkane Oxidation Mechanism Department of Chemistry

  9. Traditional Alkane Oxidation Mechanism Department of Chemistry

  10. Traditional Alkane Oxidation Mechanism Department of Chemistry

  11. Traditional Alkane Oxidation Mechanism Department of Chemistry

  12. Traditional Alkane Oxidation Mechanism H (C-H)1 345  5 411  2 kJ mol-1 1: Handbook of Chemistry and Physics, pp9.64 – 9.72, Vol 86, CRC, 2005 Department of Chemistry

  13. Traditional Alkane Oxidation Mechanism H (C-H)1 345  5 411  2 kJ mol-1 1: Handbook of Chemistry and Physics, pp9.64 – 9.72, Vol 86, CRC, 2005 Department of Chemistry

  14. Traditional Alkane Oxidation Mechanism H (C-H)1 345  5 411  2 kJ mol-1 1: Handbook of Chemistry and Physics, pp9.64 – 9.72, Vol 86, CRC, 2005 Department of Chemistry

  15. Oxidation of Methyl Oleate : GC Analysis Oxidation Conditions: 170 ºC, 20 minutes GC conditions: ZB-5 column, 50-340 ºC, 6 ºC min-1 Product Identification: EI-MS and CI-MS Time (min) Department of Chemistry

  16. Oxidation of Methyl Oleate : GC Analysis Oxidation Conditions: 170 ºC, 20 minutes GC conditions: ZB-5 column, 50-340 ºC, 6 ºC min-1 Product Identification: EI-MS and CI-MS Time (min) Department of Chemistry

  17. Oxidation of Methyl Oleate : GC Analysis Oxidation Conditions: 170 ºC, 20 minutes GC conditions: ZB-5 column, 50-340 ºC, 6 ºC min-1 Product Identification: EI-MS and CI-MS x 6 Time (min) Department of Chemistry

  18. Oxidation of Methyl Oleate : Epoxides Time (min) Department of Chemistry

  19. Oxidation of Methyl Oleate : Epoxides Oxidation Conditions: 170 ºC Department of Chemistry

  20. Epoxide Formation Mechanism C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 M. S. Stark, J. Am. Chem. Soc. 2000, 122, 4162-4170 G. Lercker, et al., J. Chromatography A. 2003, 985, 333-342 Department of Chemistry

  21. Epoxide Formation Mechanism C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 M. S. Stark, J. Am. Chem. Soc. 2000, 122, 4162-4170 G. Lercker, et al., J. Chromatography A. 2003, 985, 333-342 Department of Chemistry

  22. Epoxide Formation Mechanism C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 M. S. Stark, J. Am. Chem. Soc. 2000, 122, 4162-4170 G. Lercker, et al., J. Chromatography A. 2003, 985, 333-342 Department of Chemistry

  23. Epoxide Formation Mechanism C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 M. S. Stark, J. Am. Chem. Soc. 2000, 122, 4162-4170 G. Lercker, et al., J. Chromatography A. 2003, 985, 333-342 Department of Chemistry

  24. Epoxide Formation Mechanism C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 M. S. Stark, J. Am. Chem. Soc. 2000, 122, 4162-4170 G. Lercker, et al., J. Chromatography A. 2003, 985, 333-342 Department of Chemistry

  25. Epoxide Formation Mechanism C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 M. S. Stark, J. Am. Chem. Soc. 2000, 122, 4162-4170 G. Lercker, et al., J. Chromatography A. 2003, 985, 333-342 Department of Chemistry

  26. Reactions of Alkoxyl Radicals (e.g. 11-alkoxyl) C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 Department of Chemistry

  27. Reactions of Alkoxyl Radicals (e.g. 11-alkoxyl) C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 Department of Chemistry

  28. Oxidation of Methyl Oleate : Ketones and Alcohols e.g. e.g. Time (min) Department of Chemistry

  29. Oxidation of Methyl Oleate : Alcohols and Ketones Oxidation Conditions: 170 ºC e.g. e.g. Department of Chemistry

  30. Reactions of Alkoxyl Radicals (e.g. 11-alkoxyl) Heptyl radical Methyl-11-oxoundec-9-enoate C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 Department of Chemistry

  31. Reactions of Alkoxyl Radicals (e.g. 11-alkoxyl) Methyl-11-oxoundec-9-enoate Heptane Heptanal C. B. Whitlock, J. Am. Oil Chem. Soc., 1976, 53, 586 Department of Chemistry

  32. Oxidation of Methyl Oleate : Alkoxyl Fragmentation Methyl-11-oxoundec-9-enoate Heptanal Heptane Time (min) Department of Chemistry

  33. Oxidation of Methyl Oleate : Volatile Products Oxidation Conditions: 170 ºC Department of Chemistry

  34. Formation of Alkoxyl Radicals E. N. Frankel, W. E. Neff, W. K. Rohwedder, Lipids, 1977, 12, 901-907 E. N. Frankel, et al., J. C. S. Perkin Trans. I, 1984, 2233 Department of Chemistry

  35. Formation of Alkoxyl Radicals E. N. Frankel, W. E. Neff, W. K. Rohwedder, Lipids, 1977, 12, 901-907 E. N. Frankel, et al., J. C. S. Perkin Trans. I, 1984, 2233 Department of Chemistry

  36. Formation of Alkoxyl Radicals E. N. Frankel, W. E. Neff, W. K. Rohwedder, Lipids, 1977, 12, 901-907 E. N. Frankel, et al., J. C. S. Perkin Trans. I, 1984, 2233 Department of Chemistry

  37. Formation of Alkoxyl Radicals E. N. Frankel, W. E. Neff, W. K. Rohwedder, Lipids, 1977, 12, 901-907 E. N. Frankel, et al., J. C. S. Perkin Trans. I, 1984, 2233 Department of Chemistry

  38. Formation of Alkoxyl Radicals E. N. Frankel, W. E. Neff, W. K. Rohwedder, Lipids, 1977, 12, 901-907 E. N. Frankel, et al., J. C. S. Perkin Trans. I, 1984, 2233 Department of Chemistry

  39. Formation of Alkoxyl Radicals E. N. Frankel, W. E. Neff, W. K. Rohwedder, Lipids, 1977, 12, 901-907 E. N. Frankel, et al., J. C. S. Perkin Trans. I, 1984, 2233 Department of Chemistry

  40. Oxidation of Methyl Oleate : Alkoxyl Fragmentation Time (min) Department of Chemistry

  41. Oxidation of Methyl Oleate : Dehydrodimers e.g. Time (min) Department of Chemistry

  42. Oxidation of Methyl Oleate : Dehydrodimers Time (min) Department of Chemistry

  43. Oxidation of Methyl Oleate : Polymeric Products Oxidation Conditions: 170 ºC e.g. Department of Chemistry

  44. Simulation of Methyl Oleate Oxidation • Chemical Mechanism • Based on 2-Butene Oxidation Department of Chemistry

  45. Simulation of Methyl Oleate Oxidation MeO + O2 => allyl + HO2 allyl + O2 => allylO2 allylO2 + MeO => allylO2H + allyl allylO2H => allylO + OH allylO2 + MeO => tepox + allylO allylO2 + MeO => cepox + allylO allylO + O2 => allylket + HO2 allylO + MeO => allylOH + allyl allyl + allyl => dimer allylO2 + allylO2 => allylO + allylO + O2 allylO2 + allylO2 => allylket + allylOH + O2 HO2 + MeO => tepox + OH HO2 + MeO => cepox + OH HO2 + MeO => allyl + H2O2 OH + MeO => H2O + allyl allylO => ald1 + alkyl alkyl + MeO => alkane + allyl alkyl + O2 => alkylO2 alkylO2 + MeO => tepox + alkylO alkylO2 + MeO => cepox + alkylO alkylO + O2 => ald2 + HO2 • Chemical Mechanism • Based on 2-Butene Oxidation • 24 reactions • 22 species (7 products) Department of Chemistry

  46. Simulation of Methyl Oleate Oxidation : Epoxides Oxidation Conditions: 170 ºC Department of Chemistry

  47. Simulation of Methyl Oleate Oxidation : Epoxides Oxidation Conditions: 170 ºC Department of Chemistry

  48. Simulation of Oxidation : Alcohols and Ketones Oxidation Conditions: 170 ºC e.g. e.g. Department of Chemistry

  49. Simulation of Oxidation : Alcohols and Ketones Oxidation Conditions: 170 ºC e.g. e.g. Department of Chemistry

  50. Conclusions • Time Development of Oxidation Products Measured • Epoxides of Dominant Products • Epoxidation Dominant Fate of Peroxyl Radicals • Fragmentation of Alkoxyl Radicals Also Significant • Many Alkane Products Formed, Even in Presence of O2 • Chemical Kinetics Model of Oxidation Developed Department of Chemistry

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