Natural gas flames

The yellow color imparted to a natural gas flame originates from the ignition of sodium atoms or ions. The common source of sodium is salt (sodium chlo-... 

Many detailed reaction mechanisms are available from the Internet. GRI-Mech (www.me.berkeley.edu/gri-mech/) is an optimized detailed chemical reaction mechanism developed for describing methane and natural gas flames and ignition. The last release is GRI-Mech 3.0, which was preceded by versions 1.2 and 2.11. The conditions for which GRI-Mech was optimized are roughly 1000-2500K, lOTorr to lOatm, and equivalence ratios from 0.1 to 5 for premixed systems. 

One can model this system in principle using the mass- and ener -balance equations written with the equations of Chapter 8 with flow in the j direction and diSiision in the jc direction to obtain profiles of Cj z, x) and T z, x). However, the student can see immediately that this will be a very complex mathematical problem to solve because there are many species (at least 30 for natural gas flames), but the problem will be made even more complex because of natural convection. Since the temperature in the flame varies from... 

A photoanode comprised of flame oxidized carbon doped n-Ti02 films have been reported to perform water splitting with high photoconversion efficiencies [65]. While chemically modified n-Ti02 can be prepared by the controlled combustion of Ti metal in a natural gas flame the authors, in investigating this technique [66], have found reproducibility to be a challenge. Various authors [67,68,69] have discussed in considerable depth issues surrounding the stated photoconversion efficiencies of [65]. 

Temperature distribution in a near stoichiometrie premixed air-natural gas flame. Temperatures in°C. 

Channel Black. A variety of carbon black(qv) made by impingement of a luminous natural-gas flame against and iron plate from which it is scraped at frequent intervals Ref CondChemDict(1961), 248... 

The channel black process involves the impingement of natural gas flames on 20- to 25-cm channel irons that are slowly reciprocated over scrapers to remove soot deposits. The type of black produced is controlled by burner-tip design, burner-to-channel distance, and air supply (degree of partial combustion). 

Vick R. D. Avery, M. J. "Extraction and Identification of Organic Materials Present 1n Soot from a Natural Gas Flame" Iowa State University Journal, IS-4329, 1978. 

The rate curves of Figure 1-b indicate an early formation of hydrogen in each flame followed by immediate and rapid consumption downstream. Overall, the rate data indicate that the maximum rates of depletion of reactants are slightly less in the flame with natural gas (Flame B), while the maximum rates of formation of CO2 and H2O, are about equal in both flames. 

Measurements of temperature and concentration in CO-H2-CH4 (or natural gas) flames were carried out. Rate profiles were developed for two excess air and two slightly fuel-rich flames as a function of temperature. Substitution of natural gas for methane does not bring about a marked change in the overall reactivity of these systems. Application of a modified theory analysis to these multiple-fuel flame mixtures allows one to satisfactorily correlate calculated values of the burning velocity with measured values. 

The thermometer adaptors are available commercially (Ace Glass Company, Vineland, NJ). The platinum wire to platinum electrode connection was made by laying the wire on the foil, heating both parts to red heat with an oxygen-natural gas flame, and forcing the two together with a sharp hammer blow. 

Efficient Photochemical Water Splitting by a Chemically Modified n-Ti02. Combustion of Ti metal in a natural gas flame done to substitute carbon for some of the lattice oxygen sites. The photocatalysis performance data have been questioned (see Refs. 214-216). 213... 

Fire retardants are added to wood-polymers used for flooring and other public installations. Polymethyl methacrylate is one of the few polymers that will depolymerize into the monomer when heated to the temperature of decomposition. The monomer in the gas phase burns with an intense blue flame similar to a natural gas flame. 

On the other hand, formaldehyde is a byproduct of human activities. It is a combustion product it is in cigarette smoke, in wood combustion, and in natural gas flames. Urban air contains between 10 and 1,000 mg/m of aldehydes, depending on location. Typical concentrations are shown in Table I ... 

A carefully controlled oxygen/natural gas flame can produce acetylene if the flame is quenched after an appropriate interval. However, in all current processes, the final distribution of carbon is such that for every mole of carbon reporting to acetylene approximately two moles of carbon report to carbon monoxide, making this route primarily a synthesis gas producer. The vast amount of sensible heat in the exhaust gases needs to be recovered to maintain a reasonable thermal efficiency. By far, most of the acetylene produced presently employs this route. 

Ruiz, R., and Hilliard, J. G. "Luminosity Enhancement of Natural Gas Flames." Proceedings of 1989 International Gas Research Conference, edited by T. L. Gramer, 1345-53. Rockville, MD Govt. Institutes, 1990. 

Type L fine wire thermocouple measuring the gas temperature in a natural gas flame. 

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