The calculation of ion currents in hydrocarbon flames

✍ Scribed by B.A. Schaefer

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 361 KB
• Volume: 56
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(84)90004-x

✦ Synopsis

The calculation of ion currents in hydrocarbon flames was attempted to test a mechanism involving temperature dependence. Values of [CHI and [O] in the flame are available in some cases of premixed methane-oxygen flames, but not for the diffusion flame of H 2 and air containing hydrocarbon. For the latter cases a relationship between [CH4] and [CH] was sought, using the kinetics of the stages CH 4 ~ CH 3 ~ CH 2 ~ CH ~ CHO + and of the competitive combustion to oxygenated products. An approximate value of the ionization efficiency (q~) of CH 4 was calculated and found to agree with experimental determinations in premixed CH4~:) 2 and diffusion H2-air plus CH 4 flames. The maximum saturation current was calculated for a premixed CH4--O 2 flame using literature data, and a modified method was applied to a H2-air diffusion flame. The shape of the hydrogen flame ionization detector response curve was calculated from the data of H 2 oxidation kinetics and the ionization path CH 4 ~ CHO ÷ . The calculated curve was a reasonable representation of the experimental observations, and the calculated maximum response was within an order of magnitude of the observed value.