MRI: Operando measurements of temperature, hydrodynamics and local reaction rate in a heterogeneous catalytic reactor

Gladden, Lynn F.; Abegão, Fernando J.R.; Dunckley, Christopher P.; Holland, Daniel J.; Sankey, Mark H.; Sederman, Andrew J.

doi:10.1016/j.cattod.2009.10.012

Cited by 41 publications

(25 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the alternative case of temporally alternating measurements of gas distribution and temperature, one could perform the temperature measurements by volume selective spectroscopy measurement as demonstrated by Gladden et al [27] in well defined voxels, allowing optimized shim values, i.e. better local B0 homogeneity.…”

Section: Temperature Measurementsmentioning

confidence: 98%

“…Furthermore, a method using the temperature dependence of chemical shift difference between the two signals of ethylene glycol, well known from high resolution NMR spectroscopy [26], was adapted for temperature measurements within an NMR compatible reactor [27]. Even gas phase reactions were investigated by using hyperpolarization or remote detection techniques [28][29][30].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

NMR imaging of gas phase hydrogenation in a packed bed flow reactor

Ulpts

Dreher

Klink

et al. 2015

Applied Catalysis A: General

View full text Add to dashboard Cite

Section: Temperature Measurementsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

NMR imaging of gas phase hydrogenation in a packed bed flow reactor

Ulpts

Dreher

Klink

et al. 2015

Applied Catalysis A: General

View full text Add to dashboard Cite

“…However, recently there has been a move toward studying reactions at conditions of industrial relevance Koptyug, Khomichev, Lysova, & Sagdeev, 2008). 13 C NMR has been used to explore changes in selectivity and conversion in trickle bed reactors operating at up to 5 barg and 120 C (Akpa, Mantle, Sederman, & Gladden, 2005;Gladden et al, 2010;Sederman, Mantle, Dunckley, Huang, & Gladden, 2005). Koptyug et al have developed NMR thermometry techniques to permit the quantification of the temperature of catalyst pellets during reaction (Koptyug et al, 2008;Koptyug, Sagdeev, Gerkema, Van As, Sagdeev, 2005;Lysova, Kulikov, Parmon, Sagdeev, & Koptyug, 2012).…”

Section: Reaction Studiesmentioning

confidence: 98%

“…MRI measurements of trickle bed reactors have proven beneficial owing to the high spatial and temporal resolution that can be achieved (Anadon, Sederman, & Gladden, 2006;Gladden et al, 2010;Gladden, Lim, Mantle, Sederman, & Stitt, 2003;Sederman & Gladden, 2001. MRI can extract the distribution of gas and liquid within the three-dimensional structure of the packing.…”

Section: Hydrodynamic Studiesmentioning

confidence: 99%

Applications of tomography in bubble column and trickle bed reactors

Holland

2015

Industrial Tomography

View full text Add to dashboard Cite

“…This method is based on the pairwise addition of parahydrogen (p-H 2 ) instead of normal hydrogen (hydrogen at thermal equilibrium, n-H 2 ) in a hydrogenation reaction, i. e. when two hydrogen atoms from the same H 2 molecule are added to the same substrate molecule with breaking of magnetic symmetry, leading to the overpopulation of spin states and consequently to hyperpolarization. [55] This can be explained by the low spin density of gases compared to liquids, inhomogeneity of the magnetic field inside reactors caused by solid catalyst beads [6,8,56] and the fast diffusion of gases. [37] With homogeneous catalysts, there is a general problem of catalyst separation from the hyperpolarized product, although they still can be used for the production of HP gases, [38,39] small molecules, [40,41] including bioactive ones, [42][43][44] and examination of reactive intermediates.…”

mentioning

confidence: 99%

Robust In Situ Magnetic Resonance Imaging of Heterogeneous Catalytic Hydrogenation with and without Hyperpolarization

Kovtunov

Lebedev²,

Svyatova

et al. 2019

ChemCatChem

View full text Add to dashboard Cite

Magnetic resonance imaging (MRI) is a powerful technique to characterize reactors during operating catalytic processes. However, MRI studies of heterogeneous catalytic reactions are particularly challenging because the low spin density of reacting and product fluids (for gas phase reactions) as well as magnetic field inhomogeneity, caused by the presence of a solid catalyst inside a reactor, exacerbate already low intrinsic sensitivity of this method. While hyperpolarization techniques such as parahydrogen induced polarization (PHIP) can substantially increase the NMR signal intensity, this general strategy to enable MR imaging of working heterogeneous catalysts to date remains underexplored. Here, we present a new type of model catalytic reactors for MRI that allow the characterization of a heterogeneous hydrogenation reaction aided by the PHIP signal enhancement, but also suitable for the imaging of regular nonpolarized gases. These catalytic systems permit exploring the complex interplay between chemistry and fluid-dynamics that are typically encountered in practical systems, but mostly absent in simple batch reactors. High stability of the model reactors at catalytic conditions and their fabrication simplicity make this approach compelling for in situ studies of heterogeneous catalytic processes by MRI.Catalytic processes (e. g., hydrogenation, reforming, oxidation, etc.) are at the cornerstone of chemical and petrochemical industry [1] and, to make these processes more sustainable, control over reaction selectivity, conversion rates, mass and heat transport inside the working reactor (that is under operando conditions) is required. Magnetic resonance imaging (MRI) is a tool applicable to operando studies that provide information for example about the distribution of liquids in the catalyst pellet during hydrogenation of α-methylstyrene [2] or heptene, [3] the coke profiles within a catalyst pellet, [4] the flow of water [5] or propane [6] through a packed bed, the structure of a porous medium and the water flow during the deposition of fines, [7] or the velocities of particles in a fluidized bed. [8][9][10] MRI of reactors utilizing gases are not as developed as studies of liquids because the spin density in the gas phase is ca. 3 orders of magnitude lower relative to the condensed phase, which significantly limits the deployment of MRI for studying gases. [11] Nevertheless, a recent report showed that the distribution of the reactants and products inside a monolith type reactor can be measured even in the gas phase during ethylene hydrogenation reaction using two different catalyst supports, thereby revealing an effect of the support on the mass and heat transport. [12] Overall, to date, there are only a handful of MRI studies of the gas phase reactions with regular non-hyperpolarized gases. [13,14] The limitation of low NMR sensitivity spurs the implementation of hyperpolarization techniques, which can potentially increase the intensity of NMR signals by up to several orders of magnitude, including spin-ex...

show abstract

MRI: Operando measurements of temperature, hydrodynamics and local reaction rate in a heterogeneous catalytic reactor

Cited by 41 publications

References 24 publications

NMR imaging of gas phase hydrogenation in a packed bed flow reactor

NMR imaging of gas phase hydrogenation in a packed bed flow reactor

Applications of tomography in bubble column and trickle bed reactors

Robust In Situ Magnetic Resonance Imaging of Heterogeneous Catalytic Hydrogenation with and without Hyperpolarization

Contact Info

Product

Resources

About