On the reaction mechanism of CO{sub 2} reforming of methane over a bed of coal char
- Curtin University of Technology, Perth, WA (Australia). Centre for Fuels and Energy
CO{sub 2} reforming of methane was studied over a bed of coal char in a fixed bed reactor at temperatures between 1073 and 1223 K and atmospheric pressure with a feed composition of CH{sub 4}/CO{sub 2}/N{sub 2} in the ratio of 1:1:8. Experimental results showed that the char was an effective catalyst for the production of syngas with a maximum H{sub 2}/CO ratio of one. It was also found that high H{sub 2}/CO ratios were favoured by low pressures and moderate to high temperatures. These results are supported by thermodynamic calculations. A mechanism of seven overall reactions was studied and three catalytic reactions of CH{sub 4} decomposition, char gasification and the Boudouard reaction was identified as being of major importance. The first reaction produces carbon and H{sub 2}, the second consumes carbon, and the third (the Boudouard reaction) converts CO{sub 2} to CO while consuming carbon. Equilibrium calculations and experimental results showed that any water present reacts to form H{sub 2} and carbon oxides in the range of temperatures and pressures studied. Carbon deposition over the char bed is the major cause of deactivation. The rate of carbon formation depends on the kinetic balance between the surface reaction of the adsorbed hydrocarbons with oxygen containing species and the further dissociation of the hydrocarbon. 23 refs., 13 figs., 3 tabs.
- OSTI ID:
- 20905873
- Journal Information:
- Proceedings of the Combustion Institute, Vol. 31, Issue 2; Conference: 31. international symposium on combustion, Heidelberg (Germany), 5-11 Aug 2006; Other Information: dkzhang@che.curtin.edu.au; ISSN 1540-7489
- Country of Publication:
- United States
- Language:
- English
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