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Continuous multitubular millireactor with a Cu thin film for microwave-assisted fine-chemical synthesis / Narendra G. Patil in Industrial & engineering chemistry research, Vol. 51 N° 44 (Novembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 44 (Novembre 2012) . - pp. 14344–14354 Titre : Continuous multitubular millireactor with a Cu thin film for microwave-assisted fine-chemical synthesis Type de document : texte imprimé Auteurs : Narendra G. Patil, Auteur ; Faysal Benaskar, Auteur ; Evgeny V. Rebrov, Auteur Année de publication : 2013 Article en page(s) : pp. 14344–14354 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Multitubular  millireactor Résumé : The productivity of microwave-assisted continuous specialty chemical synthesis has been brought to a commercially interesting scale of 1 kg/day. To that end, a counter-current multitubular millireactor/heat exchanger (MTMR) assembly has been developed with the reactant flow through millitubular reactors, while the coolant flows in the shell side. The efficiency of microwave absorption under continuous operation in a single mode microwave cavity has been improved with the deposition of a thin (350 ± 40 nm) Cu film on the inner walls of the reactor tubes. This design ultimately resulted in an enhanced product (1,3-diphenyl-2-propynyl piperidine) yield of a multicomponent reaction (of piperidine, benzaldehyde, and phenylacetylene). The Cu film also improved the uniformity of microwave energy absorption in the reactor tubes along the radial direction. A near-isothermal operation was achieved by cooling with a counter-current flow of a microwave transparent coolant in the outer shell of the MTMR. A production rate of 333 ± 11 kgprod/(kgcat·h) was achieved in a single microwave cavity at 373 ± 5 K and at a total reactant flow rate of 1.66 × 10–9 m3/s. The average production rate of 1,3-diphenyl-2-propynyl piperidine in the MTMR assembly (six parallel tubes in a shell and tube reactor/heat exchanger) was 93% of the production rate in a single tube due to a slightly uneven flow and temperature distribution. Kinetically determined mean Cu film temperature was 477 ± 10 K. Although the reactor tubes were placed at an equal distance from axial symmetry (six parallel tubes in a hexagonal arrangement), a maximum temperature deviation of 8.0 ± 0.5 K was observed over the reactor tubes. The parallelization approach was demonstrated to be successful for scale up of continuously operated microwave reactors. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300754z [article] Continuous multitubular millireactor with a Cu thin film for microwave-assisted fine-chemical synthesis [texte imprimé] / Narendra G. Patil, Auteur ; Faysal Benaskar, Auteur ; Evgeny V. Rebrov, Auteur . - 2013 . - pp. 14344–14354. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 44 (Novembre 2012) . - pp. 14344–14354 Mots-clés : Multitubular  millireactor Résumé : The productivity of microwave-assisted continuous specialty chemical synthesis has been brought to a commercially interesting scale of 1 kg/day. To that end, a counter-current multitubular millireactor/heat exchanger (MTMR) assembly has been developed with the reactant flow through millitubular reactors, while the coolant flows in the shell side. The efficiency of microwave absorption under continuous operation in a single mode microwave cavity has been improved with the deposition of a thin (350 ± 40 nm) Cu film on the inner walls of the reactor tubes. This design ultimately resulted in an enhanced product (1,3-diphenyl-2-propynyl piperidine) yield of a multicomponent reaction (of piperidine, benzaldehyde, and phenylacetylene). The Cu film also improved the uniformity of microwave energy absorption in the reactor tubes along the radial direction. A near-isothermal operation was achieved by cooling with a counter-current flow of a microwave transparent coolant in the outer shell of the MTMR. A production rate of 333 ± 11 kgprod/(kgcat·h) was achieved in a single microwave cavity at 373 ± 5 K and at a total reactant flow rate of 1.66 × 10–9 m3/s. The average production rate of 1,3-diphenyl-2-propynyl piperidine in the MTMR assembly (six parallel tubes in a shell and tube reactor/heat exchanger) was 93% of the production rate in a single tube due to a slightly uneven flow and temperature distribution. Kinetically determined mean Cu film temperature was 477 ± 10 K. Although the reactor tubes were placed at an equal distance from axial symmetry (six parallel tubes in a hexagonal arrangement), a maximum temperature deviation of 8.0 ± 0.5 K was observed over the reactor tubes. The parallelization approach was demonstrated to be successful for scale up of continuously operated microwave reactors. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300754z

Enhancement of the liquid - side mass transfer in a falling film catalytic microreactor by in - channel mixing structures / Evgeny V. Rebrov in Industrial & engineering chemistry research, Vol. 51 N° 26 (Juillet 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp. 8719–8725 Titre : Enhancement of the liquid - side mass transfer in a falling film catalytic microreactor by in - channel mixing structures Type de document : texte imprimé Auteurs : Evgeny V. Rebrov, Auteur ; Thijs Duisters, Auteur ; Patrick Lob, Auteur Année de publication : 2012 Article en page(s) : pp. 8719–8725 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mass  transfer  Microreactor Résumé : Catalytic octanal oxidation with oxygen was performed at 100 °C and the total pressure of 5 and 10 bar in a falling film microreactor with varying reaction plates bearing different in-channel mixing structures. The liquid flow rate was changed in the range of 3.3–17.5 mL/min. The liquid-sided mass transfer over grooved or finned structured plates was enhanced by factors of 1.12 and 1.20, respectively, compared to that on a standard plate with 16 microchannels with dimensions of 1200 μm × 400 μm. The liquid flow rate over the structured plates could be increased by 60%–80% without any loss of octanal conversion. A two-dimensional convection and diffusion model adopted from Al-Rawashdeh et al. [Chem. Eng. Sci. 2008, 63, 5149] was formulated to simulate the reactor behavior, and its predictions describe the experimental results in terms of octanal conversion with an accuracy of 4.3% when the actual temperature distribution in the reactor plate is taken into account. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301058h [article] Enhancement of the liquid - side mass transfer in a falling film catalytic microreactor by in - channel mixing structures [texte imprimé] / Evgeny V. Rebrov, Auteur ; Thijs Duisters, Auteur ; Patrick Lob, Auteur . - 2012 . - pp. 8719–8725. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp. 8719–8725 Mots-clés : Mass  transfer  Microreactor Résumé : Catalytic octanal oxidation with oxygen was performed at 100 °C and the total pressure of 5 and 10 bar in a falling film microreactor with varying reaction plates bearing different in-channel mixing structures. The liquid flow rate was changed in the range of 3.3–17.5 mL/min. The liquid-sided mass transfer over grooved or finned structured plates was enhanced by factors of 1.12 and 1.20, respectively, compared to that on a standard plate with 16 microchannels with dimensions of 1200 μm × 400 μm. The liquid flow rate over the structured plates could be increased by 60%–80% without any loss of octanal conversion. A two-dimensional convection and diffusion model adopted from Al-Rawashdeh et al. [Chem. Eng. Sci. 2008, 63, 5149] was formulated to simulate the reactor behavior, and its predictions describe the experimental results in terms of octanal conversion with an accuracy of 4.3% when the actual temperature distribution in the reactor plate is taken into account. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301058h

Liquid – liquid flow in a capillary microreactor / Jovan Jovanovic in Industrial & engineering chemistry research, Vol. 51 N° 2 (Janvier 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1015-1026 Titre : Liquid – liquid flow in a capillary microreactor : Hydrodynamic flow patterns and extraction performance Type de document : texte imprimé Auteurs : Jovan Jovanovic, Auteur ; Evgeny V. Rebrov, Auteur ; T. A. (Xander) Nijhuis, Auteur Année de publication : 2012 Article en page(s) : pp. 1015-1026 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flow  field  Hydrodynamics  Microreactor  Liquid  liquid  flow Résumé : The capillary microreactor, with four stable operating flow patterns and a throughput range from grams per hour to kilograms per hour, presents an attractive alternative to chip-based and microstructured reactors for laboratory- and pilot-scale applications. In this article, results for the extraction of 2-butanol from toluene under different flow patterns in a water/toluene flow in long capillary microreactors are presented. The effects of the capillary length (0.4―2.2 m), flow rate (0.1-12 mL/min), and aqueous-to-organic volumetric flow ratio (0.25―9) on the slug, bubbly, parallel, and annular flow hydrodynamics were investigated. Weber-number-dependent flow maps were composed for capillary lengths of 0.4 and 2 m that were used to interpret the flow pattern formation in terms of surface tension and inertia forces. When the capillary length was decreased from 2 to 0.4 m, a transition from annular to parallel flow was observed. The capillary length had little influence on slug and bubbly flows. The flow patterns were evaluated in terms of stability, surface-to-volume ratio, throughput, and extraction efficiency. Slug and bubbly flow operations yielded 100% thermodynamic extraction efficiency, and increasing the aqueous-to-organic volumetric ratio to 9 allowed for 99% 2-butanol extraction. The parallel and annular flow operating windows were limited by the capillary length, thus yielding maximum 2-butanol extractions of 30% and 47% for parallel and annular flows, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476434 [article] Liquid – liquid flow in a capillary microreactor : Hydrodynamic flow patterns and extraction performance [texte imprimé] / Jovan Jovanovic, Auteur ; Evgeny V. Rebrov, Auteur ; T. A. (Xander) Nijhuis, Auteur . - 2012 . - pp. 1015-1026. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1015-1026 Mots-clés : Flow  field  Hydrodynamics  Microreactor  Liquid  liquid  flow Résumé : The capillary microreactor, with four stable operating flow patterns and a throughput range from grams per hour to kilograms per hour, presents an attractive alternative to chip-based and microstructured reactors for laboratory- and pilot-scale applications. In this article, results for the extraction of 2-butanol from toluene under different flow patterns in a water/toluene flow in long capillary microreactors are presented. The effects of the capillary length (0.4―2.2 m), flow rate (0.1-12 mL/min), and aqueous-to-organic volumetric flow ratio (0.25―9) on the slug, bubbly, parallel, and annular flow hydrodynamics were investigated. Weber-number-dependent flow maps were composed for capillary lengths of 0.4 and 2 m that were used to interpret the flow pattern formation in terms of surface tension and inertia forces. When the capillary length was decreased from 2 to 0.4 m, a transition from annular to parallel flow was observed. The capillary length had little influence on slug and bubbly flows. The flow patterns were evaluated in terms of stability, surface-to-volume ratio, throughput, and extraction efficiency. Slug and bubbly flow operations yielded 100% thermodynamic extraction efficiency, and increasing the aqueous-to-organic volumetric ratio to 9 allowed for 99% 2-butanol extraction. The parallel and annular flow operating windows were limited by the capillary length, thus yielding maximum 2-butanol extractions of 30% and 47% for parallel and annular flows, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476434

Phase-transfer catalysis in segmented flow in a microchannel / Jovan Jovanović in Industrial & engineering chemistry research, Vol. 49 N° 6 (Mars 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 6 (Mars 2010) . - pp. 2681–2687 Titre : Phase-transfer catalysis in segmented flow in a microchannel : fluidic control of selectivity and productivity Type de document : texte imprimé Auteurs : Jovan Jovanović, Auteur ; Evgeny V. Rebrov, Auteur ; T. A. (Xander) Nijhuis, Auteur Année de publication : 2010 Article en page(s) : pp. 2681–2687 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Catalysis  in  Segmented  Flow  Microchannel  Fluidic  Selectivity  Productivity Résumé : Precise control over the interfacial area of aqueous and organic slugs in segmented flow in a microchannel reactor provides an attractive means to optimize the yield and productivity of a phase-transfer-catalyzed reaction. Herein, we report the selective alkylation of phenylacetonitrile to the monoalkylated product in a microchannel of 250-μm internal diameter operated in a continuous and solvent-free manner in the slug-flow regime. The conversion of phenylacetonitrile increased from 40% to 99% as a result of a 97% larger slug surface-to-volume ratio when the volumetric aqueous-to-organic phase flow ratio was raised from 1.0 to 6.1 at the same residence time. The larger surface-to-volume ratio significantly promoted catalyst phase transfer but decreased selectivity because of the simultaneous increase of the rate of the consecutive reaction to the dialkylated product. There exists an optimum flow ratio with a maximum productivity. Conversion and selectivity in the microchannel reactor were both found to be significantly larger than in a stirred reactor. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9017918 [article] Phase-transfer catalysis in segmented flow in a microchannel : fluidic control of selectivity and productivity [texte imprimé] / Jovan Jovanović, Auteur ; Evgeny V. Rebrov, Auteur ; T. A. (Xander) Nijhuis, Auteur . - 2010 . - pp. 2681–2687. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 6 (Mars 2010) . - pp. 2681–2687 Mots-clés : Catalysis  in  Segmented  Flow  Microchannel  Fluidic  Selectivity  Productivity Résumé : Precise control over the interfacial area of aqueous and organic slugs in segmented flow in a microchannel reactor provides an attractive means to optimize the yield and productivity of a phase-transfer-catalyzed reaction. Herein, we report the selective alkylation of phenylacetonitrile to the monoalkylated product in a microchannel of 250-μm internal diameter operated in a continuous and solvent-free manner in the slug-flow regime. The conversion of phenylacetonitrile increased from 40% to 99% as a result of a 97% larger slug surface-to-volume ratio when the volumetric aqueous-to-organic phase flow ratio was raised from 1.0 to 6.1 at the same residence time. The larger surface-to-volume ratio significantly promoted catalyst phase transfer but decreased selectivity because of the simultaneous increase of the rate of the consecutive reaction to the dialkylated product. There exists an optimum flow ratio with a maximum productivity. Conversion and selectivity in the microchannel reactor were both found to be significantly larger than in a stirred reactor. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9017918