Positioning of the reaction zone for gas–liquid reactions in catalytic membrane reactor by coupling results of mass transport and chemical reaction study

Berčič, Gorazd; Pintar, Albin; Levec, Janez

doi:10.1016/j.cattod.2005.06.008

Cited by 12 publications

(2 citation statements)

References 13 publications

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“…One method of improving the gas/liquid/solid contact could be to use contactor type catalytic membrane reactors (CMR) [9,10,11] as interfacial contactors with an organic compound solution and air (or oxygen) separately fed from both sides of the catalytic membrane. The gas overpressure can shift the gas-liquid interface location into the membrane wall, which is closer to the catalytic zone, thus realizing several advantages: the oxygen concentration in contact with the catalyst layer is maximized, the desorption of pollutants into the gaseous phase is favored, the catalyst exposure to leaching is reduced, substantial flexibility for operative conditions is available and scale-up issues are facilitated.…”

Section: Introductionmentioning

confidence: 99%

Catalysts with Cerium in a Membrane Reactor for the Removal of Formaldehyde Pollutant from Water Effluents

et al. 2016

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Abstract:We report the synthesis of cerium oxide, cobalt oxide, mixed cerium, and cobalt oxides and a Ce-Co/Al 2 O 3 membrane, which are employed as catalysts for the catalytic wet oxidation (CWO) reaction process and the removal of formaldehyde from industrial effluents. Formaldehyde is present in numerous waste streams from the chemical industry in a concentration low enough to make its recovery not economically justified but high enough to create an environmental hazard. Common biological degradation methods do not work for formaldehyde, a highly toxic but refractory, low biodegradability substance. The CWO reaction is a recent, promising alternative that also permits much lower temperature and pressure conditions than other oxidation processes, resulting in economic benefits. The CWO reaction employing Ce-and Co-containing catalysts was carried out inside a slurry batch reactor and a membrane reactor. Experimental results are reported. Next, a mixed Ce-Co oxide film was supported on an γ-alumina membrane used in a catalytic membrane reactor to compare formaldehyde removal between both types of systems. Catalytic materials with cerium and with a relatively large amount of cerium favored the transformation of formaldehyde. Cerium was present as cerianite in the catalytic materials, as indicated by X-ray diffraction patterns.

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Section: Introductionmentioning

confidence: 99%

Catalysts with Cerium in a Membrane Reactor for the Removal of Formaldehyde Pollutant from Water Effluents

et al. 2016

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“…The resulting catalytic reaction zone is usually 8270 mm thick [30]. Liquid reactants come into direct contact with the gaseous reactants in the catalytic regions of the membrane reactors [29,30].…”

Section: Introductionmentioning

confidence: 99%

Modeling of gas–liquid reactions in porous membrane microreactors

Jani¹,

Aran²,

Weßling³

et al. 2012

Journal of Membrane Science

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Increased gas solubility in nanoliquids: Improved performance in interfacial catalytic membrane contactors

Pera‐Titus¹,

Miachon²,

Dalmon³

2008

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).The kinetics of gas-liquid catalytic reactions can be strongly promoted when these are performed in interfacial catalytic membrane reactors instead of other three-phase reactors such as slurry stirrers or trickle beds. The well-defined gas-liquid-catalyst contact in this system avoiding diffusional limitations is usually argued as the main reason for such enhancement. In this work, using nitrobenzene hydrogenation as a model reaction, we propose that this increased catalytic performance might also be attributed, at least partially, to increased gas solubilities in mesoconfined solvents (or simply ''nanoliquids'') in interfacial contactors overcoming the values predicted by Henry's Law. To support this hypothesis, we provide experimental evidence of a dramatic increase of H 2 solubility in confined ethanol using mesoporous c-Al 2 O 3 as confining solid. Gas-liquid solubilities can be enhanced up to five times over the corresponding bulk values for nanoliquid sizes lower than 15 nm as long as the gas-liquid interface is confined in a mesoporous array. In such a situation, the volume of the gasliquid interface is no longer negligible compared to the total volume of the confined liquid, and the high surface excess concentrations of the gas adsorbed on the liquid surface make solubility grow up dramatically. According to these measurements, we discuss how nanoliquids might form in catalytic membrane contactors, which gas-liquid configuration in the reactor appears to be more appropriate, and how the structure of the mesoporous catalytic layer contributes to their increased gas solubilization performance.

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Positioning of the reaction zone for gas–liquid reactions in catalytic membrane reactor by coupling results of mass transport and chemical reaction study

Cited by 12 publications

References 13 publications

Catalysts with Cerium in a Membrane Reactor for the Removal of Formaldehyde Pollutant from Water Effluents

Catalysts with Cerium in a Membrane Reactor for the Removal of Formaldehyde Pollutant from Water Effluents

Modeling of gas–liquid reactions in porous membrane microreactors

Increased gas solubility in nanoliquids: Improved performance in interfacial catalytic membrane contactors

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