Hydrogen in flames

J.E.M. Goldsmith Two-step saturated fluorescence detection of atomic hydrogen in flames. Opt. Lett. 10, 116 (1985)... 

Total sulfur in air, most of which is sulfur dioxide, can be measured by burning the sample in a hydrogen-rich flame and measuring the blue chemiluminescent emission from sulfur atom combination to excited S2 (313). Concentrations of about 0.01 ppm can be detected. 

Transparent (Invisible) Flames Some materials have nearly nonluminous flames, which may not be visible, especially in the daytime. For example, hydrogen has a nearly nonvisible flame in the daytime. A person may walk unaware into a hydrogen leak flame. Some other materials, including some alcohols such as methanol, also have nearly nonluminous flames and may be unusually hazardous because the flames cannot be seen in the daytime. 

Flame Photometric Detector3 With the flame photometric detector (FPD), as with the FID, the sample effluent is burned in a hydrogen/air flame. By using optical filters to select wavelengths specific to sulfur and phosphorus and a photomultiplier tube, sulfur or phosphorus compounds can be selectively detected. 

The product B2H6 is diborane (8), a colorless gas that bursts into flame in air. On contact with water, it immediately reduces the hydrogen in the water ... 

Potter, A.E., Jr., and Anagnostou, E., Reaction order in the hydrogen-bromine flame from the pressure dependence of quenching diameter, Proc. Comb. Inst., 7 347,1959. 

Sung, C.J., Makino, A., and Law, C.K., On stretch-affected pulsating instability in rich hydrogen/air flames Asymptotic analysis and computation. Combust. Flame, 128, 422, 2002. 

D. Escudi4 P- Paranthoen, and M. Trinite 1983, Modification of turbulent tiow-field by an oblique premixed hydrogen-air flame, in Flames, Laser and Reactive Systems (selected papers from the Eighth International Colloquium on Gasdynamics of Explosions and Reactive Systems), Progress in Astronautics and Aeronautics Series, AIAA Inc. publishers, pp. 147-163. 

Active heterogeneous catalysts have been obtained. Examples include titania-, vanadia-, silica-, and ceria-based catalysts. A survey of catalytic materials prepared in flames can be found in [20]. Recent advances include nanocrystalline Ti02 [24], one-step synthesis of noble metal Ti02 [25], Ru-doped cobalt-zirconia [26], vanadia-titania [27], Rh-Al203 for chemoselective hydrogenations [28], and alumina-supported noble metal particles via high-throughput experimentation [29]. 

In this section we apply the adaptive boundary value solution procedure and the pseudo-arclength continuation method to a set of strained premixed hydrogen-air flames. Our goal is to predict accurately and efficiently the extinction behavior of these flames as a function of the strain rate and the equivalence ratio. Detailed transport and complex chemical kinetics are included in all of the calculations. The reaction mechanism for the hydrogen-air system is listed in Table... 

Strain Rate Extinction. We performed a sequence of strain rate calculations for an 8.4% and a 9.3% (mole fraction) hydrogen-air flame. The equivalence ratios of these flames are = 0.219 and = 0.245, respectively. In both cases the Lewis number of the deficient reactant (hydrogen) was significantly less than one. In particular, at the input jet, the Lewis numbers were equal to 0.29 for both the 8.4% flame and the 9.3% flame. We also found that these values did not change by more than 15% through the flame. 

Figure 2. Temperature profile in K for the 9.3% (mole fraction) hydrogen-air flame with a strain rate of a = 200 sec ...

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