Abstract
In this study we investigated the conversion of aqueous methyl-ethyl-ketone (MEK) to olefin fuel precursors over ZnxZryOz mixed oxide catalysts. Experiments were carried out in water as MEK is intended to be produced from the dehydration of 2,3-butanediol in fermentation broth which is highly diluted in water. We demonstrated that ZnxZryOz catalysts are highly effective for converting aqueous MEK to C4-C5 olefins. High selectivity to olefins equal to 85% was reached at 92% per pass conversion when under H2 atmosphere. Catalyst stability was demonstrated for 60 hours' time on stream, highlighting the potential for upgrading 2,3-butanediol contained in fermentation broth without the need for energy-intensive water separation. Increased concentration of MEK in the aqueous feed results in increased activity towards olefin production. However, water inhibits catalyst deactivation from coking. A mechanistic investigation revealed the impact of the reaction environment (inert or reducing atmosphere) on the reaction pathways. In an inert environment, the mechanism involves consecutive aldol condensation of MEK and 3-pentanone intermediate. Under reducing conditions two reaction pathways compete with each other as MEK hydrogenation to butenes occurs concurrently with the aldol condensation/decomposition.
Original language | American English |
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Pages (from-to) | 3393-3400 |
Number of pages | 8 |
Journal | ChemCatChem |
Volume | 11 |
Issue number | 15 |
DOIs | |
State | Published - 7 Aug 2019 |
Bibliographical note
Publisher Copyright:© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
NREL Publication Number
- NREL/JA-5100-73271
Keywords
- 2,3-butanediol
- aqueous
- bio-fuels
- methyl-ethyl-ketone
- olefins