Effects of hydrogen addition on methane catalytic combustion in a microtube

Zhang, Yongsheng; Zhou, Junhu; Yang, Weijuan; Liu, Maosheng; Cen, Kefa

doi:10.1016/j.ijhydene.2006.07.023

Cited by 69 publications

(16 citation statements)

References 15 publications

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“…The addition of hydrogen to the initial hydrocarbon-air mixture offers a way to light-off catalytic combustion of hydrocarbon on catalyst. The thermal effect of hydrogen addition is to provide enough heat to reach a catalyst temperature at which hydrocarbon oxidation will light-off, and the temperature of light-off depends on hydrocarbon concentration [27,28]. Another effect of hydrogen addition is chemical effect, which can significantly reduce the temperature of light-off and flame quenching distance [29].…”

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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“…In addition, hydrogen addition is also an effective method for the improving combustion characteristics. Compared with hydrocarbons, hydrogen has numerous advantages, such as shorter quenching distance, higher diffusion coefficient, and catalytic auto ignition at room temperature (Changwei and Shuofeng, 2009;Choi et al, 2008;Deutschmann et al, 1996;Wang et al, 2012;Zamashchikov and Tikhomolov, 2011;Zhang et al, 2007;Zhou et al, 2009). Yu et al (1986) indicated that hydrogen addition to methane results in higher flame propagation speed.…”

Section: Introductionmentioning

confidence: 99%

Effect of Catalyst Length and Hydrogen Addition on the Combustion Characteristics ofn-Butane in a Catalytic Swiss-Roll Combustor

Zhong

Yang

2015

Combustion Science and Technology

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The effect of catalyst length and hydrogen addition on the combustion characteristics of n-butane in a catalytic Swiss-roll combustor was studied experimentally. The results show that the 4.5-mm ceramic with Pt catalyst slightly outperforms the 3.0-and 6.0-mm ceramics. However, changing only the catalyst length does not expand the lower flammable limits to lean fuel. Further experiments on the combustor with the 4.5-mm ceramic show that the addition of hydrogen to flammable mixtures can expand the lower flammable limits of such mixtures to lower than 0.5. Analyses on exhaust gas and stable combustion temperature indicate that hydrogen supplies heat through complete combustion and enhances the n-butane conversion ratio. A high amount of hydrogen is favorable for flammable range expansion. Moreover, a higher amount of hydrogen can further reduce the lower limits.

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“…Many experimental and numerical investigations which have been conducted are concentrated on the effects of some crucial options such as micro-tube/channel geometry Kim and Maruta, 2006;, heat loss (Hua et al, 2005;, thermal and radical quenching , fluid flow characteristic and equivalence ratio (Hua et al, 2005;Zhang et al, 2007), and pre-heating of fresh entrance reactive mixture (Hua et al, 2005;Ju and Choi, 2003;Leach and Cadou, 2005;Norton and Vlachos, 2003;Raimondeau et al, 2002) on combustion phenomena in micro-combustors. As results of many investigations, it can be inferred that the micro-combustor…”

Section: Introductionmentioning

confidence: 99%

Effect of Wall Thermal Conductivity on Hydrogen-Assisted Catalytic Ignition Characteristics of Propane-Air at Micro-Scales in Different Feeding Modes

Chen¹,

Gao²,

Xu³

2015

Frontiers in Heat and Mass Transfer

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Effect of wall thermal conductivity on hydrogen self-ignition and hydrogen-assisted ignition of propane-air mixtures in different feeding modes from ambient cold-start conditions were investigated numerically with chemical kinetic model in Pt/γ-Al2O3 catalytic micro-combustors. For the steady and transient state, effect of wall thermal conductivity on self-ignition characteristics of lean hydrogen-air mixtures was presented, and hydrogenassisted combustion of propane-air mixtures was investigated numerically in the co-feed mode and the sequential feed mode. The computational results indicate the large thermal inertia of the micro-combustor solid structure leads to slow temperature dynamics, and transient response is dominated by the thermal inertia. The heat localization in poorly conducting walls leads to fast ignition and shorter steady state time. In general, the concentration of hydrogen required for propane ignition increased with increasing wall thermal conductivity, decreasing inlet velocity, and decreasing inlet equivalence ratio of propane-air mixtures. In the co-feed mode, the combustion characteristics of hydrogen-assisted propane qualitatively resemble the selectively preheating initial portion of the combustion chamber wall. In the sequential feed mode, the time taken to reach steady state, the hydrogen cut-off time, the propane ignition time and the cumulative propane emissions increased with increasing wall thermal conductivity; the ignition characteristics are similar to partially preheating the initial segment for low and moderate wall thermal conductivity values (0.5 and 20 W/m· K); however, the ignition characteristics are close to completely heating the micro-combustor wall for high wall thermal conductivity values (200 W/m· K).

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Effects of hydrogen addition on methane catalytic combustion in a microtube

Cited by 69 publications

References 15 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

Effect of Catalyst Length and Hydrogen Addition on the Combustion Characteristics ofn-Butane in a Catalytic Swiss-Roll Combustor

Effect of Wall Thermal Conductivity on Hydrogen-Assisted Catalytic Ignition Characteristics of Propane-Air at Micro-Scales in Different Feeding Modes

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