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Navarro-Fuentes F, Keane MA, Ni XW. Continuous Hydrogenation of Alkynol in a Continuous Oscillatory Baffled Reactor. Org Process Res Dev 2021. [DOI: 10.1021/acs.oprd.0c00458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Francisca Navarro-Fuentes
- EPSRC Centre for Continuous Manufacturing and Crystallization (CMAC), Centre for Oscillatory Baffled Applications (COBRA), School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Mark Andrew Keane
- EPSRC Centre for Continuous Manufacturing and Crystallization (CMAC), Centre for Oscillatory Baffled Applications (COBRA), School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Xiong-Wei Ni
- EPSRC Centre for Continuous Manufacturing and Crystallization (CMAC), Centre for Oscillatory Baffled Applications (COBRA), School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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Abstract
AbstractThree-phase catalysis, for example, hydrogenation, is a special branch of chemical reactions involving a hydrogen reactant (gas) and a solvent (liquid) in the presence of a metal porous catalyst (solid) to produce a liquid product. Currently, many reactors are being used for three-phase catalysis from packed bed to slurry vessel; the uniqueness for this type of reaction in countless processes is the requirement of transferring gas into liquid, as yet there is not a unified system of quantifying and comparing reactor performances. This article reviews current methodologies in carrying out such heterogeneous catalysis in different reactors and focuses on how to enhance reactor performance from gas transfer perspectives. This article also suggests that the mass transfer rate over energy dissipation may represent a fairer method for comparison of reactor performance accounting for different types/designs of reactors and catalyst structures as well as operating conditions.
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Affiliation(s)
- Xiong-Wei Ni
- School of Engineering and Physical Sciences, Division of Chemical Engineering, Heriot–Watt University, Edinburgh, United Kingdom
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The Hydrodynamics and Mixing Performance in a Moving Baffle Oscillatory Baffled Reactor through Computational Fluid Dynamics (CFD). Processes (Basel) 2020. [DOI: 10.3390/pr8101236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Oscillatory baffled reactors (OBRs) have attracted much attention from researchers and industries alike due to their proven advantages in mixing, scale-up, and cost-effectiveness over conventional stirred tank reactors (STRs). This study quantitatively investigated how different mixing indices describe the mixing performance of a moving baffle OBR using computational fluid dynamics (CFD). In addition, the hydrodynamic behavior of the reactor was studied, considering parameters such as the Q-criterion, shear strain rate, and velocity vector. A modification of the Q-criterion showed advantages over the original Q-criterion in determination of the vortices’ locations. The dynamic mesh tool was utilized to simulate the moving baffles through ANSYS/Fluent. The mixing indices studied were the velocity ratio, turbulent length scale, turbulent time scale, mixing time, and axial dispersion coefficient. We found that the oscillation amplitude had the most significant impact on these indices. In contrast, the oscillatory Reynolds number did not necessarily describe the mixing intensity of a system. Of the tested indices, the axial dispersion coefficient showed advantages over the other indices for quantifying the mixing performance of a moving baffle OBR.
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Abstract
AbstractOscillatory flow reactors (OFRs) superimpose an oscillatory flow to the net movement through a flow reactor. OFRs have been engineered to enable improved mixing, excellent heat- and mass transfer and good plug flow character under a broad range of operating conditions. Such features render these reactors appealing, since they are suitable for reactions that require long residence times, improved mass transfer (such as in biphasic liquid-liquid systems) or to homogeneously suspend solid particles. Various OFR configurations, offering specific features, have been developed over the past two decades, with significant progress still being made. This review outlines the principles and recent advances in OFR technology and overviews the synthetic applications of OFRs for liquid-liquid and solid-liquid biphasic systems.
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Abstract
Alkenols are commercially important chemicals employed in the pharmaceutical and agro-food industries. The conventional production route via liquid phase (batch) alkynol hydrogenation suffers from the requirement for separation/purification unit operations to extract the target product. We have examined, for the first time, the continuous gas phase hydrogenation (P = 1 atm; T = 373 K) of primary (3-butyn-1-ol), secondary (3-butyn-2-ol) and tertiary (2-methyl-3-butyn-2-ol) C4 alkynols using a 1.2% wt. Pd/Al2O3 catalyst. Post-TPR, the catalyst exhibited a narrow distribution of Pdδ- (based on XPS) nanoparticles in the size range 1-6 nm (mean size = 3 nm from STEM). Hydrogenation of the primary and secondary alkynols was observed to occur in a stepwise fashion (-C≡C- → -C=C- → -C-C-) while alkanol formation via direct -C≡C- → -C-C- bond transformation was in evidence in the conversion of 2-methyl-3-butyn-2-ol. Ketone formation via double bond migration was promoted to a greater extent in the transformation of secondary (vs. primary) alkynol. Hydrogenation rate increased in the order primary < secondary < tertiary. The selectivity and reactivity trends are accounted for in terms of electronic effects.
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Navarro‐Fuentes F, Keane M, Ni X. The effects of modes of hydrogen input and reactor configuration on reaction rate and H
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efficiency in the catalytic hydrogenation of alkynol to alkenol. CAN J CHEM ENG 2019. [DOI: 10.1002/cjce.23615] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Francisca Navarro‐Fuentes
- EPSRC Centre for Continuous Manufacturing and Crystallization (CMAC), Centre for Oscillatory Baffled Applications (COBRA), School of Engineering and Physical SciencesHeriot‐Watt University Edinburgh UK
| | - Mark Keane
- EPSRC Centre for Continuous Manufacturing and Crystallization (CMAC), Centre for Oscillatory Baffled Applications (COBRA), School of Engineering and Physical SciencesHeriot‐Watt University Edinburgh UK
| | - Xiong‐Wei Ni
- EPSRC Centre for Continuous Manufacturing and Crystallization (CMAC), Centre for Oscillatory Baffled Applications (COBRA), School of Engineering and Physical SciencesHeriot‐Watt University Edinburgh UK
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Jimeno G, Lee YC, Ni XW. Smoothed particle hydrodynamics – A new approach for modeling flow in oscillatory baffled reactors. Comput Chem Eng 2019. [DOI: 10.1016/j.compchemeng.2019.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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