The autothermal behavior of platinum catalyzed hydrogen oxidation: experiments and modeling

Fernandes, Neil E.; Park, Y.K.; Vlachos, Dionisios G.

doi:10.1016/s0010-2180(98)00162-x

Cited by 47 publications

(35 citation statements)

References 30 publications

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“…Therefore, the addition of hydrogen [17,18], hydrogen peroxide [19] and nitrous oxide [20] in hydrocarbon fuels has received increasing attention recently. Hydrogen-air mixtures are known to be self-igniting over platinum under very fuel-lean conditions [21,22] but fuel-richer mixtures exhibit ignition temperature above room temperature [22,23]. The self-ignition nature of hydrogen-air mixtures over platinum offers an opportunity to self-ignite hydrocarbons in catalytic micro-combustors, and a way toward elimination of the ignition source from micro-scale devices resulting in further reduction of system size.…”

Section: Introductionmentioning

confidence: 99%

Kinetic effects of hydrogen addition on the catalytic self-ignition of methane over platinum in micro-channels

Chen

Gao

2016

Chemical Engineering Journal

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Section: Introductionmentioning

confidence: 99%

Kinetic effects of hydrogen addition on the catalytic self-ignition of methane over platinum in micro-channels

Chen

Gao

2016

Chemical Engineering Journal

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“…These experiments were carried out with a low Reynolds number forced flow or with no flow at all. Other experiments by Behrendt et al [7] and Fernandes et al [8] addressed the critical temperature issue in a high Reynolds number stagnation flow configuration. The differences between the two sets of experimental results reveal a lack of universality of the ignition temperature concept and the need of a more profound understanding of the problem.…”

Section: Introductionmentioning

confidence: 99%

“…It is also of practical importance, among other reasons because the catalytic removal of molecular hydrogen in nuclear plants may alleviate one of the main concerns in nuclear power safety. Typically, catalytic combustion processes have been studied either by numerical simulations using elementary chemistry [1][2][3][4][5][6][7][8][9] or by large activation energy asymptotic analyses using a one-step overall reaction mechanism [10][11][12][13][14]. Williams et al [1] proposed a model for the catalytic combustion of hydrogen at high temperatures.…”

Section: Introductionmentioning

confidence: 99%

Transient ignition and combustion of diluted hydrogen/air mixtures by a thin catalytic wire

Treviño

Higuera²,

Liñán³

2002

Proceedings of the Combustion Institute

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This paper reports on a study of transient ignition and combustion of hydrogen/air mixtures by a heated, thin catalytic wire in a natural convection environment. Modeling of the process is accomplished via a reduced set of heterogeneous kinetic processes which include dissociative adsorption and desorption of both reactants, three fast surface reactions of the Langmiur-Hinshelwood type, and the desorption reaction of the adsorbed product, H 2 O(s). The overall surface reaction rate is found to be limited by the adsorption rate of molecular oxygen, which depends on the concentration of molecular oxygen close to the surface of the wire and the distribution of empty sites in the catalyst. The analysis allows the determination of the critical conditions for ignition and the ignition delay time as a function of the important physicochemical parameters. The resulting wire temperatures and the critical value of the external heating rate at ignition are computed. The analysis shows how the ignition temperature increases as the external heating rate increases. The configuration dependence of the ignition temperature is taken as an indication that the use of a critical Damkö hler number provides a better ignition condition than the ignition temperature concept. A self-sustained combustion regime for strong diluted mixtures is described.

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“…In general, the catalytic combustion process has been studied by either numerical simulations, using elementary chemistry [1][2][3][4][5][6][7][8][9], or by large activation energy asymptotic analyses, using one-step overall reaction mechanisms [10][11][12][13][14]. The basic principles of heterogeneous catalysis have been described elsewhere [1,15].…”

Section: Introductionmentioning

confidence: 99%

“…They used either a forced flow (low Reynolds number) or simply no forced flow [5]. There are other experiments involving stagnationpoint flows at high Reynolds numbers [7,8]. The ignition temperatures obtained using both experimental configurations differ, and a relationship between them is needed.…”

Section: Introductionmentioning

confidence: 99%

Autoignition of hydrogen/air mixtures by a thin catalytic wire

Treviño

Liñán

Kurdyumov

2000

Proceedings of the Combustion Institute

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The autoignition of the catalytic reaction of hydrogen/air mixtures on thin palladium wires is analyzed in this paper. The reduced heterogeneous kinetics is modeled with a mechanism that includes the dissociative adsorption of both reactants, together with three surface reactions of the Langmuir-Hinshelwood type, and the desorption reaction of the adsorbed product, H 2 O(s). We show that for the description of the ignition conditions, this mechanism can be simplified to a single overall surface reaction involving the temperature and gas concentrations of the reactants at the surface of the wire. The resulting overall rate for the surface reaction has been tested with existing experimental results, after describing the transport of heat and reactants, by natural convection, in the gas phase for a wide range of Rayleigh numbers. The critical conditions for the catalytic ignition have been deduced using high activation energy asymptotics for the desorption kinetics of the most efficiently adsorbed reactant, H(s).

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The autothermal behavior of platinum catalyzed hydrogen oxidation: experiments and modeling

Cited by 47 publications

References 30 publications

Kinetic effects of hydrogen addition on the catalytic self-ignition of methane over platinum in micro-channels

Kinetic effects of hydrogen addition on the catalytic self-ignition of methane over platinum in micro-channels

Transient ignition and combustion of diluted hydrogen/air mixtures by a thin catalytic wire

Autoignition of hydrogen/air mixtures by a thin catalytic wire

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