The catalytic decomposition of methane offers an interesting route to obtain a stream of pure COx-free hydrogen and carbon materials in the solid phase with potential applications to improve the viability of the process. In this work, we have studied the kinetics of this process using a silica-supported nickel catalyst in a packed bed reactor. In order to ensure the intrinsic kinetic regime, the effects of external and mass transfer on the overall kinetics were examined at relevant reaction conditions. The external mass transfer was found to affect the kinetics at 500 ⁰C and a space velocity of 80 h–1. The internal mass transfer was found to not limit the kinetics when a catalyst particle size in the range of 1000-2000 µm was used. Within the intrinsic kinetic regime, we found that the reaction order with respect to methane is in the range of 0.77-0.94, the activation energy is 110 kJ mol–1 and the rate determining step is the dissociation of the first C-H bond. In addition, the kinetics of the catalyst deactivation follows a first-order behavior with respect to the activity of the catalyst, with an activation energy of 125 kJ mol–1. At the end of the study, a mathematical model for the best-fit model was found using MATLAB. With the whole set of data, the best fit is obtained with a Langmuir-Hinshelwood type rate law.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/675596 |
| Date | 12 1900 |
| Creators | Babkoor, Mohammed |
| Contributors | Castaño, Pedro, Physical Science and Engineering (PSE) Division, Ruiz-Martinez, Javier, Mishra, Himanshu |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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