Dissertation
How the Exothermicity of the Fischer–Tropsch Reaction Is Driving R&D: Examples for Self-Sustained Thermokinetic Oscillations and Long-Term Steady-State Operational Control
Washington State University
Doctor of Philosophy (PhD), Washington State University
2023
DOI:
https://doi.org/10.7273/000005319
Abstract
The Fischer–Tropsch reaction is an exothermic process that converts synthesis gas into liquid hydrocarbons, playing a crucial role in sustainable fuel production. The exothermic nature of the Fischer–Tropsch reaction presents both opportunities and challenges, as it can induce oscillations in reaction rate and selectivity, offering prospects for investigating unresolved reaction mechanisms. However, it can also lead to thermal challenges that impact catalyst efficiency and stability. In this study, we investigate the exothermic nature of the Fischer–Tropsch reaction by exploring self-sustained thermokinetic oscillations in a gradient-free ambient pressure reactor and the long-term stability of the reaction in a high-pressure reactor. Our methods include exploring the oscillatory behavior of two cobalt-based catalysts, Co1Cu1Ce1 and Co2Ce1, and developing a highly productive and robust core@shell HeatPath SiC@Co/Re/Al2O3 catalyst. We demonstrate that the experimentally observed oscillations can be effectively modeled using a kinetic scheme, which incorporates the CO insertion mechanism, the thermal activation of C-O bond breaking, and periodic temperature forcing. Notably, different catalyst compositions exhibit distinct oscillatory behavior during the reaction. The core@shell HeatPath SiC@Co/Re/Al2O3 catalyst demonstrates exceptional long-term stability and high-temperature operation, with low CH4 selectivity and high long-chain hydrocarbon yield. These properties are attributed to the heat dissipation capabilities of the SiC pellets. Our findings contribute to a deeper understanding of the complex reaction mechanisms involved in the Fischer–Tropsch synthesis reaction and support the development of more efficient and selective catalysts for sustainable fuel production.
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Details
- Title
- How the Exothermicity of the Fischer–Tropsch Reaction Is Driving R&D
- Creators
- Rui Zhang
- Contributors
- Norbert Kruse (Advisor)Yong Wang (Advisor)Steven R Saunders (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- School of Chemical Engineering and Bioengineering
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 176
- Identifiers
- 99901031341101842
- Language
- English
- Resource Type
- Dissertation