Comparative study of the influence of CO2 and H2O on the chemical structure of lean and rich methane-air flames at atmospheric pressure

Abstract

A comparative study of the influence of CO 2 and H 2 O on both lean and rich CH 4 -air laminar flames is performed. Six premixed flames are stabilized on a flat flame burner at atmospheric pressure: lean (with the equivalence ratio maintained constant at φ = 0.7) and rich (with the equivalence ratio maintained constant at φ = 1.4) CH 4 -air, CH 4 -CO 2 -air, and CH 4 -H 2 O-air flames. These flames are studied experimentally and numerically. The [CO 2 ]/[CH 4 ] and [H 2 O]/[CH 4 ] ratios are kept equal to 0.4 for both flames series. Species mole fraction profiles are measured by gas chromatography and Fourier transform infrared spectroscopy analyses of gas samples withdrawn along the vertical axis by a quartz microprobe. Flames structures are computed by using the ChemkinII/Premix code. Four detailed combustion mechanisms are used to calculate the laminar flame velocities and species mole fraction profiles: GRI-Mech 3.0, Dagaut, UCSD, and GDFkin 3.0.

The Effects of CO2 Additional on Flame Characteristics in the CH4/N2/O2 Counterflow Diffusion Flame

“…Various other studies [ 20 , 21 , 22 , 23 , 24 ] investigated the effects of CO 2 on soot or NO X emissions in different fuels. Moreover, some researchers studying CO 2 dilution combustion focused on the influence of CO 2 on other characteristics of the gas flame, such as the adiabatic flame temperature (AFT) [ 17 , 25 ], extinction limits [ 6 , 26 , 27 , 28 ], flame instability [ 29 , 30 , 31 , 32 , 33 ], H 2 intermediate formation [ 34 , 35 ], and CO concentration [ 36 ] using various fuels.…”

Combustion of kerosene sprayed with a jet of superheated steam

“…A decrease in NOx emissions is usually associated with an increase in the heat capacity of mixture during combustion of fuels (physical effect): hydrogen-air [4] mixture, combustion of methane-air mixture [5][6][7], and propane-butane mixture [8]. At the same time, it is noted in some papers [9,10] that the addition of steam leads not only to dilution of the combustible mixture (physical effect), but it also changes the process of some elementary reactions (chemical effect). It is noted in [11] that the use of steam injection technology is more efficient than the use of recirculation gas technology in the presence of steam.…”

Effect of CO2 Addition on the Structure of Premixed Fuel-Rich CH4/O2/N2 and C3H8/O2/N2 Flames Stabilized on a Flat Burner at Atmospheric Pressure

“…It is well-known that small hydrocarbons, such as acetylene, ethylene, propargyl, diacetylene, and benzene, among others, play an important role in the formation of PAH, but the studies of the effect of CO 2 addition on the kinetics of their formation in flames are very scarce, e.g.,.refs − . In particular, Matynia et al have investigated the influence of CO 2 addition on the chemical structure of premixed burner-stabilized methane/air flames at atmospheric pressure using gas chromatography and Fourier-transform infrared spectroscopy to analyze samples withdrawn from the flame by a quartz microprobe. Renard and co-workers have studied how the addition of CO 2 influences the mole fraction profiles of soot precursors in premixed ethylene/oxygen/argon flames stabilized on a Botha–Spalding type burner at low pressure using molecular beam mass spectrometry.…”