The goal of this project was to study the reactivity of thin pyrolitic carbon films on quartz, formed from propylene, methane and butadiene, using the methane conversion reaction as a test. The reactivity was compared to that of quartz. The rate of dissociation of methane on the carbon surface was as much as forty times greater than on quartz. The actual rate increase depended on the precursor of the carbon film. When the reproducibility of the carbon films was tested, the rate was observed to decrease with consecutive experiments. Subsequent analysis showed that small amounts of carbon were deposited during the course of each reaction. Since small amounts of carbon caused inhibition, but carbon films caused catalysis, the rate of formation of ethane, a measure of the rate of dissociation of methane, was determined as a function of the amount of carbon. The rate was also determined as a function of methane reactant pressure and temperature. All the results indicated that the methane was dissociated on the carbon surface to form methyl and hydrogen radicals. The increase in formation of these radicals led to the increased rate. The subsequent mechanism was similar to the homogeneous mechanism of methane decomposition. In order to confirm this result, the rate was determined in a reaction vessel with a different surface to volume ratio. The surface mechanism was confirmed. The carbon film was characterized using different techniques. The hydrogen content of the films was determined and related to the reactivity of the carbon formed from different precursors. The film was studied by electron microscopy, XRD, FTIR and mass spectrometry. An overall mechanism was developed for the methane decomposition reaction in the presence of carbon which was extended over the different temperature and pressure conditions studied. Finally, a new technique of synthesizing a catalyst containing carbon and iron, and results obtained in the study of water vapour gasification and methane conversion in the presence of this catalyst are discussed.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/9910 |
| Date | January 1994 |
| Creators | Venkateswaran, Rashmi. |
| Contributors | Back, M., |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Detected Language | English |
| Type | Thesis |
| Format | 201 p. |
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