Direct oxidation of methane to methanol /
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1992.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | For direct oxidation of methane to methanol, a commercial process has not been developed. Therefore, this study is to gain an increased understanding of the reactions occurring in methane oxidation, to investigate potential catalysts and to develop kinetic models for the reactions. For homogeneous and heterogeneous reactions, 2 - 4% of oxygen and 96 - 98% of methane were used as a feed at 50 atmospheres. The selectivity of methanol was 30 - 55% for homogeneous and heterogeneous reactions. Experimental results and the pseudo kinetic model for homogeneous reaction show that carbon monoxide is produced from methane oxidation and further oxidation of methanol. The proposed pseudo kinetic model for homogeneous reaction and free radical kinetic model accurately predict the methane conversion and product selectivities. Experimental results and the kinetic models suggest that the methanol oxidation to carbon monoxide increases with increasing oxygen concentration. Pyrex bead with surface area to volume of 9420 cm^-1 were found to significantly inhibit homogeneous oxidation of methane. As the surface to volume ratio decreased the inhibition of the reactions decreased. At surface area to volume ratio of 8.7 cm^-1 which corresponds to the empty tube the effect of reactor wall appeared to be negligible. When experiments were conducted at residence times and temperatures such that the oxygen conversion was 100%, the methanol selectivity did not vary significantly except at temperature greater than 700 K, i.e. once oxygen was consumed the reaction products were essentially stable for temperatures less than 700 K. In an empty reactor, i.e. no beads or catalysts 100% oxygen conversion was calculated to occur at residence times greater than 8 seconds. The conversion of methane and the selectivity of each product for different mixed oxide catalysts are essentially the same at 100% oxygen conversion. The results suggest that homogeneous oxidation in the void volume of catalyst bed occurs to a significant extent relative to the heterogeneous reaction. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Chemical Engineering." |
| Physical Description: | xx, 177 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |