The influence of carbon dioxide on smoke formation and stability in methane-oxygen-carbon dioxide flames

✍ Scribed by Douglas Hainsworth; M. Pourkashanian; Andrew P. Richardson; Joanne L. Rupp; Alan Williams

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 290 KB
• Volume: 75
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(95)00265-0

✦ Synopsis

The effect of replacing nitrogen in combustion air by carbon dioxide in a laminar, atmospheric methane diffusion flame was investigated experimentally and by numerical modelling. Measurements included flame temperature, carbon monoxide concentrations and direct observation and photographic investigation of the flame shape and behaviour. The experimental results indicate a substantial reduction of scattered light intensity and flame volume. When a sufficient amount of carbon dioxide is added to the oxidant, the sooting tendency and flame volume are reduced. In addition, the effect of replacing nitrogen by carbon dioxide in the flame gases on the rate of formation of key combustion intermediates, such as hydroxyl radicals and ethyne, was investigated theoretically by using the Sandia laminar counterflow diffusion flame computer model. This showed that, in addition to a reduction in flame temperature, there were significant reductions in hydroxyl radical and ethyne concentrations, the net result being a reduction in the soot-forming tendency of these flames.