NMR imaging of low pressure, gas-phase transport in packed beds using hyperpolarized xenon-129

Pavlovskaya, Galina; Six, Joseph S.; Meersman, Thomas; Gopinathan, Navin; Rigby, Sean P.

Abstract

© 2015 American Institute of Chemical Engineers. Gas-phase magnetic resonance imaging (MRI) has been used to investigate heterogeneity in mass transport in a packed bed of commercial, alumina, catalyst supports. Hyperpolarized 129Xe MRI enables study of transient diffusion for microscopic porous systems using xenon chemical shift to selectively image gas within the pores, and, thence, permits study of low-density, gas-phase mass-transport, such that diffusion can be studied in the Knudsen regime, and not just the molecular regime, which is the limitation with other current techniques. Knudsen-regime diffusion is common in many industrial, catalytic processes. Significantly, larger spatial variability in mass transport rates across the packed bed was found compared to techniques using only molecular diffusion. It has thus been found that that these heterogeneities arise over length-scales much larger than ∼100 μm.

• Journal Article Type: Article
• Acceptance Date: Jun 27, 2015
• Online Publication Date: Jul 14, 2015
• Publication Date: Jan 1, 2015
• Deposit Date: Feb 5, 2016
• Publicly Available Date: Feb 5, 2016
• Journal: AIChE Journal
• Print ISSN: 0001-1541
• Electronic ISSN: 1547-5905
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 61
• Issue: 11
• Pages: 4013-4019
• DOI: https://doi.org/10.1002/aic.14929
• Keywords: gas-phase magnetic resonance imaging, hyperpolarized xenon, Knudsen diffusion, catalyst support
• Public URL: https://nottingham-repository.worktribe.com/output/981406
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1002/aic.14929/abstract
• Additional Information: This is the peer reviewed version of the following article: Pavlovskaya, G., Six, Joseph S., Meersman, T., Gopinathan, N., Rigby, S. (2015) NMR Imaging of low pressure, gas-phase transport in packed beds using hyperpolarized xenon-129. AIChE Journal 61(11) 4013-4016, which has been published in final form at http://dx.doi.org/10.1002/aic.14929. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.