This investigation is concerned with the determination of high temperature gas reaction kinetics (primarily of acetylene decomposition) by using flame parameters. Steady-state flame propagation theory is employed to deduce overall activation energies and orders from the variation of burning velocity with temperature and pressure respectively. The development of experimental technique and apparatus is presented which made possible, for the first time, the stabilisation of an acetylene decomposition flame on a burner. To allow operation under these somewhat hazardous conditions, specially developed equipment is described which includes a safe acetylene compressor, sintered plate flow meters, and an annular burner. The theory and practice of this method for deducing overall kinetics is tested first on premixed propane- and ethylene-air flames. Several flame propagation theories are adapted in an attempt to obtain useful expressions for determining kinetics from measured variations in burning velocity. The theory of Semenoff, Fratk-Kamenetsky and Zeldovich is shown to be the most suitable and capable of predicting overall kinetics for hydrocarbon-air combustion, which are in good agreement with values reported in other investigations. It is also shown that by considering a specified intermediate reaction rather than the complete reaction, overall flame propagation theory may be capable of deducing actual radical kinetics. From observations and results obtained from acetylene, the reaction processes taking place in a freely propagating acetylene decomposition flame are shown to be distinctly different from those occurring in low temperature pyrolysis or shock waves. It is proposed that this anomaly is caused by dissociated hydrogen molecules and their subsequent diffusion and reaction. Finally, a reaction mechanism is postulated which accounts for the results.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:602274 |
| Date | January 1963 |
| Creators | Chase, John Donald |
| Contributors | Weinberg, F.J. ; Burgoyne, J. H. ; Ubbelohde, A. R. |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/13663 |
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