Decomposition pathway and kinetic analysis of perfluoroketone C <sub>5</sub> F <sub>10</sub> O
Li Chen, Boya Zhang, Xingwen Li
Abstract
Abstract Recently, perfluoroketone C 5 F 10 O has been seen as a promising alternative gas for sulphur hexafluoride (SF 6 ), of which the global warming potential (GWP) is extremely high. C 5 F 10 O has a good insulation property and the GWP value is only 1, thus can be used as insulation medium in gas-insulated switchgears. In this study, the decomposition pathway of C 5 F 10 O and the recombination processes of free radicals are firstly explored. Secondly, the rate constants of the reactions are calculated based on the variational transition state theory, which then are fitted in the NIST form. The results not only provide the basic data for the chemical kinetics calculations, but also supplementary data for the NIST database. Finally, the chemical kinetic calculations are performed to study the decomposition characteristics at 400 °C and 700 °C. Only 4% C 5 F 10 O decomposes at 400 °C, while 96% decomposes at 700 °C. The stable products like CO, C 2 F 4 , C 2 F 6 , C 3 F 6 are formed. The mole fraction of CF 4 is above 10 –10 at 400 °C. A certain amount of C 2 F 2 is produced at 700 °C. Besides, precise chemical kinetic composition results at steady state during the thermal decomposition of C 5 F 10 O are obtained. By analyzing the energy change of reactions, the formation of products is explained theoretically. The results not only reveal the decomposition mechanism of C 5 F 10 O and recombination mechanism of the stable products, but also provide the guidance for electrical engineering.