Methane-oxygen flame

Vapor-Phase Mechanisms. Phosphoms flame retardants can also exert vapor-phase flame-retardant action. Trimethyl phosphate [512-56-1] C H O P, retards the velocity of a methane—oxygen flame with about the same molar efficiency as antimony trichloride (30,31). Both physical and chemical vapor-phase mechanisms have been proposed for the flame-retardant action of certain phosphoms compounds. Physical (endothermic) modes of action have been shown to be of dominant importance in the flame-retardant action of a wide range of non-phosphoms-containing volatile compounds (32). 

Bregeon B., Gordon A.S., and Williams F.H., Near-limit downward propagation of hydrogen and methane flames in oxygen-nitrogen mixtures. Combust. Flame, 33 33-45,1978. 

This method is used to determine sodium and potassium in food, water and blood serum. The flame can be hydrogen/oxygen, methane/ oxygen or methane/air fueled. Wavelength selection can be by filter, prism Fig. 9.2 or grating and by either one or two detectors. 

Chelliah, H.K., and F. A. Williams. 1990. Aspects of the structure and extinction of diffusion flames in methane-oxygen-nitrogen systems. Combustion Flame 80 17-48. 

Figure 7.1-3. Steady flame when oxygen is injected into supercritical 70/30 water/methane mixture at 100 MPa and 450°C.

Foner and Hudson (25), however, detected only CH3 in the mass spectra of methane-oxygen flames. 

Hydrogen atoms are responsible for the disappearance of oxygen by the reaction H + 02 —> OH + O. Oxygen atoms are in excess in the methane-oxygen flame, and they probably play a part in the reactions of... 

The role of antimony halides as flame-retardant species in the gaseous phase is well established when SbX3 (X = chlorine or bromine) is introduced into premixed methane-oxygen flames, atomic antimony and antimony monoxide are found in the flame.43 Sb203 was shown by mass spectrometry to be present only in the preflame zone and no antimony-halogen species could be detected in the flame itself. 

Fig. 34, Composition profile of the cool and second stage flames during acetaldehyde oxidation [56] (a) x, Acetaldehyde <, carbon monoxide o, methane , oxygen — temperature, (b) Carbon dioxide +, formaldehyde methanol.

H.K. Chelliah and F.A. Williams, Aspects of the Structure and Extinction of Diffusion Flames in the Methane-Oxygen-Nitrogen Systems, Comb, and Flame 80 (1990) 17-48. 

The hydrocarbon (methane or naphtha) and oxygen are preheated before introduction into a combustion chamber where, after passing through a venturi, they enter the burner block fitted with a hundred or so channels. Small amounts of oxygen introduced in countercurrent flow enhance the stability of the flame. The oxygen to hydrocarbon ratio is regulated s o that pan (about one-third) of the hydrocarbon is burned, mid the remainder cracked. The gas formed is quenched with water at a level of the combustion chamber corresponding to the maximum acetylene production- The coke formed is withdrawn and separated. 

Similar sets of reactions may readily be written down for carbon monoxide/oxygen, acetylene/oxygen, hydrogen/chlorine, methane/ oxygen, or ammonia/oxygen flames, and are subject to the same... 

Fig. 3. Characteristic profiles of a methane-oxygen flame (Mo atm, 7.8% CHj) (a) aerodynamic profiles (b) temperature profiles (c) major species (d) intermediates (e) radicals. From Fristrom et al. (1960).

---