Elucidating the ionic liquid distribution in monolithic SILP hydroformylation catalysts by magnetic resonance imaging

Marinkovic, Jakob Maximilian; Benders, Stefan; García-Suárez, Eduardo J.; Weiß, Alexander; Gundlach, Carsten; Haumann, Marco; Küppers, Markus; Blümich, Bernhard; Fehrmann, Rasmus; Riisager, Anders

doi:10.1039/c9ra09515b

Cited by 13 publications

(11 citation statements)

References 40 publications

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“…An identical SILP Rh‐catalyst system has been immobilized by wet‐impregnation on porous SiC monoliths and applied in gas‐phase hydroformylation of 1‐butene over 20 h time‐on‐stream, where a steady‐state conversion close to 80 % was obtained. Remarkably, the system showed 98 % selectivity for n ‐pentanal, which demonstrated the formation of active Rh‐biphephos complexes, while aldol‐condensation side products were formed only around 2–3 % [98] …”

Section: Reusable Hydroformylation Catalystsmentioning

confidence: 99%

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Reusable Catalysts for Hydroformylation‐Based Reactions

2021

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Catalytic hydroformylation is an important reaction, widely studied by academics and applied in the chemical industry, and it is a paradigmatic example of a chemical reaction that is aligned with most of the Green Chemistry principles. In the last years, the global requirement for more sustainable chemical processes has boosted the development of more active, selective, and reusable hydroformylation catalysts. In this review, we highlight the most recent advances regarding the creation and expansion of reusable catalysts for hydroformylation and sequential processes that use hydroformylation as central reaction. The most relevant strategies for immobilization of hydroformylation catalysts are discussed, along with a critical analysis of their application in synthesis, based on catalytic activity, selectivity, and reusability.

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Section: Reusable Hydroformylation Catalystsmentioning

confidence: 99%

“…Remarkably, the system showed 98 % selectivity for n-pentanal, which demonstrated the formation of active Rh-biphephos complexes, while aldol-condensation side products were formed only around 2-3 %. [98]…”

Section: Metal Complexes and Metals Onto Solid Supportsmentioning

confidence: 99%

Reusable Catalysts for Hydroformylation‐Based Reactions

2021

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“…Membrane wetting is mostly addressed for membrane contactors [30], membrane distillation [27,31,32], microsieves [33], and monoliths [34]. However, literature states that microfiltration and ultrafiltration membrane performance is significantly influenced by its wetting state [35][36][37][38].…”

Section: Background On Wettingmentioning

confidence: 99%

In-situ investigation of wetting patterns in polymeric multibore membranes via magnetic resonance imaging

Wypysek

Kalde

Pradellok

et al. 2021

Journal of Membrane Science

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Wetting of the membrane to displace air or conditioning liquids is important to exploit the complex porosity of a filtration membrane. This study reveals the details of wetting in multibore membrane based filtration modules. Using magnetic resonance imaging (MRI), we quantify the fluid distribution patterns during initial membrane wetting in dead-end permeation mode. The spatio-temporal evolution of aqueous copper sulfate solution wetting the membrane fibers was investigated as a function of the applied flux, packing density, and position along the membrane module length. Three initial wetting conditions were examined: delivery-state membranes, ethanol-washed and dried (air-filled) membranes, and ethanol-filled membranes. Significant changes in wetting patterns were observed due to interfacial and polymer swelling effects. This in-situ investigation reveals a slow wetting progression over six hours and more to obtain complete wetting, even at high fluxes of 200 LMH. However, an increased flux leads to faster wetting kinetics as the evolving wetting patterns are flux dependent. Packing density of the multibore fibers additionally impacts the wetting kinetics by shifting the prevalent pressure conditions. Although in dead-end mode, the wetting progression is non-uniform along the membrane module length. In addition to this parameter study, different pre-wetting agents' effect on the displacement behavior was investigated in depth. This study helps to understand (a) complex wetting phenomena inside multibore membranes in dead-end filtration, (b) the membranes' interaction with their surroundings due to neighboring membranes, and (c) the effect of the used fluid system for displacement on the resulting wetting patterns.

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“…[23] For this technique, however, the authors dried the membranes before the measurement. In contrast, magnetic resonance imaging (MRI) can study internal flux and pathways and fouling phenomena of multibore membranes in-situ and non-invasively [17,[24][25][26].…”

Section: Introductionmentioning

confidence: 99%

How does porosity heterogeneity affect the transport properties of multibore filtration membranes?

Wypysek

Rall

Neef

et al. 2021

Journal of Membrane Science

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The prediction of pressure and flow distributions inside porous membranes is important if the geometry deviates from singlebore tubular geometries. This task remains challenging, especially when considering local porosity variations caused by lumenand shell-side membrane skins and macro-and micro-void structures, all of them present in multibore membranes.This study analyzes pure water forward and reverse permeation and backwashing phenomena for a polymeric multibore membrane with spatially-varying porosity and permeability properties using computational fluid dynamics simulations. The heterogeneity of porosity distribution is experimentally characterized by scanning electron microscopy scans and reconstructed cuboids of X-ray micro-computed tomography scans. The reconstructed cuboids are used to determine porosity, pore size distribution, and intrinsic permeability in the membrane's porous structure in all spatial directions. These position-dependent properties are then applied to porous media flow simulations of the whole membrane domain with different properties for separation layer, support structure, and outside skin layer. Various cases mimicking the pure water permeation, fouling, and backwashing behavior of the membrane are simulated and compared to previously obtained MRI measurements. This work reveals (a) anisotropic permeability values and isoporosity in all directions and (b) differing contributions of each lumen channel to the total membrane performance, depending on the membrane-skin's properties. This study encourages to pertain the quest of understanding the interaction of spatially distributed membrane properties and the overall membrane module performance of multibore membranes.

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Elucidating the ionic liquid distribution in monolithic SILP hydroformylation catalysts by magnetic resonance imaging

Abstract: The action of the liquid catalyst phase in monolithic silicon carbide supported ionic liquid-phase (SILP) Rh-catalysts provide important insight toward industrial upscaling for gas-phase hydroformylation.

Cited by 13 publications

References 40 publications

Reusable Catalysts for Hydroformylation‐Based Reactions

Reusable Catalysts for Hydroformylation‐Based Reactions

In-situ investigation of wetting patterns in polymeric multibore membranes via magnetic resonance imaging

How does porosity heterogeneity affect the transport properties of multibore filtration membranes?

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