Dissertation
Single-Step Conversion of Ethanol to Butadiene or N-Butene-Rich Olefins Over Metal Supported on ZrO2/SiO2 Catalysts With Tailored Metal and Lewis Acid Sites
Washington State University
Doctor of Philosophy (PhD), Washington State University
2022
DOI:
https://doi.org/10.7273/000005262
Abstract
Ethanol is a promising platform chemical for renewable production of a wide range of distillate fuels and chemicals. Continuing advancements in production efficiency and feedstock diversification will contribute to surplus ethanol production past the ‘blend wall’, generating competitively priced feedstock for conversion to compounds traditionally derived from oil. While this provides an opportunity for producers of ethanol to expand their product offerings, robust processes for ethanol conversion to fuels and chemicals are currently deficient. This dissertation involves the development of a multifunctional catalyst system composed of metal-supported ZrO2/SiO2 with tailored metal and Lewis acid sites for producing either butadiene or n-butenes from ethanol with outstanding activity, selectivity, and stability. Butadiene is a valuable precursor in the petrochemical industry used to produce many synthetic rubber materials. Producing butadiene from ethanol is beneficial as ethylene manufacturers, the main production source for butadiene, now produce less butadiene as a co-product due to a shift to lighter steam cracker feedstocks. Butenes are a high-volume commodity chemical useful in the production of distillate range fuels. Direct conversion of ethanol to n-butene-rich olefins is a significant improvement of the current state-of-the-art alcohol-to-jet process as it involves one less unit operation. Ag dispersion and alkali dopant effects on the Ag/ZrO2/SBA-16 system were investigated to effectively limit dehydration side-product formation, optimizing butadiene productivity. Ag was found to have a promotional effect on the intermediate Meerwein-Ponndorf-Verley reduction step of the ethanol to butadiene mechanism. It was found that a product slate rich in linear butenes could be formed (rather than butadiene) over the Ag/ZrO2/SBA-16 system when operated at pressure and under H2 instead of N2. A mechanistic study using operando NMR clarified the reaction mechanism, indicating that butene was primarily formed through the reduction of butadiene. An extensive deactivation study was also performed to identify key methods of deactivation over the catalyst during the formation of butenes. This work enables an understanding of structure-activity relationships for the catalytic system needed to make the renewable production of butadiene or n-butenes-rich olefins from ethanol possible.
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Details
- Title
- Single-Step Conversion of Ethanol to Butadiene or N-Butene-Rich Olefins Over Metal Supported on ZrO2/SiO2 Catalysts With Tailored Metal and Lewis Acid Sites
- Creators
- Austin David Winkelman
- Contributors
- Yong Wang (Advisor)Steven Saunders (Committee Member)Hongfei Lin (Committee Member)Zheming Wang (Committee Member)Vanessa Dagle (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 413
- Identifiers
- 99901019938601842
- Language
- English
- Resource Type
- Dissertation