Study of the kinetics of aviation oils thermal conversion under non-isothermal conditions

The paper discusses the results of a kinetic study of the thermal decomposition of MS-8P, TN-98, and TN-600 aviation oils under conditions of continuous heating at a constant rate of 5 K/min to a temperature of 1 073 K. An integral method was used to describe the reaction mechanism and determine the macrokinetic parameters. It has been established that, from a phenomenological point of view, the average reaction of aviation oils conversion under the experimental conditions corresponds to the reaction model described by the surface-limited reaction equation (MS-8P), the power law (TN-98) and the model described by the three-dimensional diffusion-limited reaction equation (TN-600). When dividing the averaged reaction into two reactions (the first is completed at a temperature of 550–600 K, the second at a temperature of 638–655 K), it is determined that the first reaction is described by the reaction equation of the 2nd order (MS-8P), the first order (TN-98) and the reaction equation of one-dimensional diffusion (TN-600), and the second the reaction equation of the first order (three types of oil). The activation energy of the first reaction was 99 kJ/mol (MS-8P), 145.6 kJ/mol (TN-98) and 57.4 kJ/mol (TN-600), the value of the pre-exponential factor was – 144 241 567 min–1 (MS-8P), 62 161 395 942 min–1 (TN-98) and 236.16 min–1 (TN600). The activation energy of the second reaction is 160 kJ/mol (MS-8P), 91.6 kJ/mol (TN-98) and 127.1 kJ/mol (TN-600), the pre-exponential factor is 8.81 ‧ 1011 min–1 (MS-8P), 1.26 ‧ 104 min–1 (TN-98) and 2.04 ‧ 108 min–1 (TN-600). It is shown that the use of these values of the activation energy and the pre-exponential factor leads to agreement between the calculated values of the degree of decomposition of the studied oil samples and the experimental ones in the range of values of the degree of decomposition from 0 to 1.

1. Svishchev G. P. (ed.). Aviation: Encyclopedia. Moscow, Great Russian Encyclopedia, 1994. 735 p. (in Russian).

2. Konyaev E. A., Nemchikov M. L. Himmototology of aviation oils and hydraulic fluids. Moscow, Moscow State Technical University of Civil Aviation, 2008. 81 p. (in Russian).

3. Novikov D. K., Fakleev S. V. Supports and seals for aircraft engines and power plants. Samara, Publishing house of Samara State Aerospace University, 2011. 124 p. (in Russian).

4. Danilov V. F., Litvinenko A. N., Akhsanov M. M., Timerbaev R. M. (compilers). Oils, lubricants and special liquids. Elabuga, Publishing House of the Branch of K(P)FU, 2013. 216 p. (in Russian).

5. Kissinger H. E. Reaction kinetics in differential thermal analysis. Analytical Chemistry, 1957, vol. 29, no. 11, pp. 1702–1706. https://doi.org/10.1021/ac60131a045

6. Akahira T., Sunose T. Transactions of Joint Convention of Four Electrical Institutes, Paper № 246, 1969 Research Report Chiba Institute of Technology. Journal of Science Education and Technology, 1971, vol. 16, pp. 22–31.

7. Friedman H. Kinetics of thermal degradation of char-forming plastics from thermogravimetry. Application to a phenolic plastic. Journal of Polymer Science Part C: Polymer Symposia, 1964, vol. 6, no. 1, pp. 183–195. https://doi.org/10.1002/polc.5070060121

8. Flynn J. H., Wall L. A. A quick, direct method for determination of activation energy from thermogravimetric data. Journal of Polymer Science Part B: Polymer Letters, 1966, vol. 4, iss. 5, pp. 323–328. https://doi.org/10.1002/pol.1966.110040504

9. Ozava T. A new method of analyzing thermogravimetric data. Bulletin of the Chemical Society of Japan, 1965, vol. 38, no. 11, pp. 1881–1886. https://doi.org/10.1246/bcsj.38.1881

10. Coats A. W., Redfern J. P. Kinetics parameters from thermogravimetric data. Nature, 1964, vol. 201, no. 4914, pp. 68–69. https://doi.org/10.1038/201068a0

11. Criado J. V. Kinetic analysis of DTA data from master curves. Thermochimica Acta, 1978, vol. 24, no. 1, pp. 186–189. https://doi.org/10.1016/0040-6031(78)85151-x

12. Malko M. V., Vasilevich S. V., Mitrofanov A. V., Mizonov V. E. An innovate method of thermogravimetric data analysis. Izvestiya Vysshikh Uchebnykh Zavedenii, Seriya Khimiya i Khimicheskaya Tekhnologiya = ChemChemTech, 2021, vol. 64, iss. 3, pp. 24–32. https://doi.org/10.6060/ivkkt.20216403.6348

13. Vasilevich S. V., Malko M. V., Shaporova E. A. Determination of the activation energy of thermal conversion of fuel on the example of aviation kerosene. Aviatsionnyi vestnik = Aviation Bulletin, 2021, no. 4, pp. 8–14 (in Russian).

14. Mitrofanov A. V., Mizonov V. E., Malko M. V., Vasilevich S. V., Zarubin Z. V. Formal kinetic approaches to the description of thermal decomposition of materials – problems of parameter identification and results interpretation: A brief review. Izvestiya Vysshikh Uchebnykh Zavedenii, Seriya Khimiya i Khimicheskaya Tekhnologiya = ChemChemTech, 2022, vol. 65, iss. 7, pp. 6–16. https://doi.org/10.6060/ivkkt.20226507.6579

15. Vyazovkin S., Wight Ch. A. Model-free and Model-fitting Approaches to Kinetic Analysis of Isothermal and Nonisothermal Data. Thermochimica Acta, 1999, vol. 340–341, pp. 53–68. https://doi.org/10.1016/s0040-6031(99)00253-1

16. Han Yu. Theoretical Study of Thermal Analysis Kinetics. Theses and Dissertations-Mechanical Engineering Thesis. Lexington, Kentuki, USA, 2014. Available at: https://core.ac.uk/download/pdf/232563059.pdf

17. Ebrahimi-Kahrizsangi R., Abbasi M.H. Evaluation of reality of Coats-Redfern method for kinetic analysis of non-isothermal TGA. Transactions of Nonferrous Metals Society of China, 2008, vol. 18, iss. 1, pp. 217–221. https://doi.org/10.1016/s1003-6326(08)60039-4

18. Kozlov A. N., Svishchev D. A., Khudyakova G. I., Ryzhkov A. F. Kinetic analysis of thermochemical conversion of solid fuels. Himija tverdogo topliva = Chemistry of solid fuel, 2017, vol. 51, no. 4, pp. 205–213. https://doi.org/10.3103/s0361521917040061

19. Braun R. L., Burnham A. K., Reynolds J. G., Clarkson J. E. Pyrolysis kinetics for lacustrine and marine source rocks by programmed micropyrolysis. Energy & Fuels, 1991, vol. 5, iss. 5, pp. 192–204. https://doi.org/10.1021/ef00025a033