scholarly journals Improving Productivity of Multiphase Flow Aerobic Oxidation Using a Tube-in-Tube Membrane Contactor

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 95 ◽  
Author(s):  
Michael Burkholder ◽  
Stanley Gilliland ◽  
Adam Luxon ◽  
Christina Tang ◽  
B. Gupton
Keyword(s):  
Flow Reactor ◽  
Aerobic Oxidation ◽  
Flow Chemistry ◽  
Packed Bed ◽  
Space Time ◽  
Catalytic Reactions ◽  
Packed Bed Reactor ◽  
Membrane Contactor ◽  
Flow Reactors ◽  
Space Time Yield

The application of flow reactors in multiphase catalytic reactions represents a promising approach for enhancing the efficiency of this important class of chemical reactions. We developed a simple approach to improve the reactor productivity of multiphase catalytic reactions performed using a flow chemistry unit with a packed bed reactor. Specifically, a tube-in-tube membrane contactor (sparger) integrated in-line with the flow reactor has been successfully applied to the aerobic oxidation of benzyl alcohol to benzaldehyde utilizing a heterogeneous palladium catalyst in the packed bed. We examined the effect of sparger hydrodynamics on reactor productivity quantified by space time yield (STY). Implementation of the sparger, versus segmented flow achieved with the built in gas dosing module (1) increased reactor productivity 4-fold quantified by space time yield while maintaining high selectivity and (2) improved process safety as demonstrated by lower effective operating pressures.

scholarly journals Self-Immobilizing Biocatalysts Maximize Space–Time Yields in Flow Reactors

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 164 ◽  
Author(s):  
Theo Peschke ◽  
Patrick Bitterwolf ◽  
Silla Hansen ◽  
Jannis Gasmi ◽  
Kersten Rabe ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Lactobacillus Brevis ◽  
Packed Bed ◽  
Cascade Reactions ◽  
Space Time ◽  
Flow Reactors ◽  
Great Utility ◽  
Platform Comparison ◽  
Cross Platform ◽  
Coated Surfaces

Maximizing space–time yields (STY) of biocatalytic flow processes is essential for the establishment of a circular biobased economy. We present a comparative study in which different biocatalytic flow reactor concepts were tested with the same enzyme, the (R)-selective alcohol dehydrogenase from Lactobacillus brevis (LbADH), that was used for stereoselective reduction of 5-nitrononane-2,8-dione. The LbADH contained a genetically encoded streptavidin (STV)-binding peptide to enable self-immobilization on STV-coated surfaces. The purified enzyme was immobilized by physisorption or chemisorption as monolayers on the flow channel walls, on magnetic microbeads in a packed-bed format, or as self-assembled all-enzyme hydrogels. Moreover, a multilayer biofilm with cytosolic-expressed LbADH served as a whole-cell biocatalyst. To enable cross-platform comparison, STY values were determined for the various reactor modules. While mono- and multilayer coatings of the reactor surface led to STY < 10, higher productivity was achieved with packed-bed reactors (STY ≈ 100) and the densely packed hydrogels (STY > 450). The latter modules could be operated for prolonged times (>6 days). Given that our approach should be transferable to other enzymes, we anticipate that compartmentalized microfluidic reaction modules equipped with self-immobilizing biocatalysts would be of great utility for numerous biocatalytic and even chemo-enzymatic cascade reactions under continuous flow conditions.

scholarly journals Catalysis-in-a-Box: Robotic Screening of Catalytic Materials in the Time of COVID-19

2020 ◽  
Author(s):  
Gaurav Kumar ◽  
Hannah Bossert ◽  
Daniel McDonald ◽  
Anargyros Chatzidmitriou ◽  
M. Alexander Ardagh ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Low Cost ◽  
Packed Bed ◽  
Reaction Rates ◽  
Laboratory Scale ◽  
Materials Testing ◽  
Kinetic Measurements ◽  
Flow Reactors ◽  
Activation Barriers ◽  
Micro Flow

<p></p><p>The emergence of a viral pandemic has motivated the transition away from traditional, labor-intensive materials testing techniques to new automated approaches without compromising on data quality and at costs viable for academic laboratories. Reported here is the design and implementation of an autonomous micro-flow reactor for catalyst evaluation condensing conventional laboratory-scale analogues within a single gas chromatograph (GC), enabling the control of relevant parameters including reactor temperature and reactant partial pressures directly from the GC. Inquiries into the hydrodynamic behavior, temperature control, and heat/mass transfer were sought to evaluate the efficacy of the micro-flow reactor for kinetic measurements. As a catalyst material screening example, a combination of four Brønsted acid catalyzed probe reactions, namely the dehydration of ethanol, 2-propanol, 1-butanol, and the dehydra-decyclization of 2-methyltetrahydrofuran on a solid acid HZSM-5 (Si/Al 140), were carried out in the temperature range 403-543 K for the measurement of apparent reaction kinetics. Product selectivities, proton-normalized reaction rates, and apparent activation barriers were in agreement with measurements performed on conventional packed bed flow reactors. Furthermore, the developed micro-flow reactor was demonstrated to be about ten-fold cheaper to fabricate than commercial automated laboratory-scale reactor setups and is intended to be used for kinetic investigations in vapor-phase catalytic chemistries, with the key benefits including automation, low cost, and limited experimental equipment instrumentation.</p><p></p>

scholarly journals Development of a flat membrane microchannel packed-bed reactor for scalable aerobic oxidation of benzyl alcohol in flow

2019 ◽  
Vol 377 ◽  
pp. 120086 ◽  
Author(s):  
Gaowei Wu ◽  
Enhong Cao ◽  
Peter Ellis ◽  
Achilleas Constantinou ◽  
Simon Kuhn ◽  
...  
Keyword(s):  
Benzyl Alcohol ◽  
Aerobic Oxidation ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Oxidation Of Benzyl Alcohol ◽  
Flat Membrane

scholarly journals Ozone-Mediated Amine Oxidation and Beyond: A Solvent Free, Flow-Chemistry Approach

2021 ◽  
Author(s):  
Eric Skrotzki ◽  
Jaya Kishore Vandavasi ◽  
Stephen Newman
Keyword(s):  
Organic Molecules ◽  
Flow Chemistry ◽  
Packed Bed ◽  
High Reactivity ◽  
Solvent Free ◽  
Packed Bed Reactor ◽  
Primary Amines ◽  
Amine Oxidation ◽  
Synthetic Utility ◽  
Free Oxidation

Ozone is a powerful oxidant, most commonly used for oxidation of alkenes to carbonyls. The synthetic utility of other ozone-mediated reactions is hindered by its high reactivity and propensity to over-oxidize organic molecules, including most solvents. This challenge can largely be mitigated by adsorbing both substrate and ozone onto silica gel, providing a solvent-free oxidation method. In this manuscript, a flow-based packed bed reactor approach is described that provides exceptional control of reaction temperature and time of this reaction to achieve improved control and chemoselectivity over this challenging reaction. A powerful method to oxidize primary amines into nitroalkanes is achieved. Examples of pyridine, C–H bond, and arene oxidations are also demonstrated, confirming the system is generalizable to diverse ozone-mediated processes.<br>

A Novel Reactor Configuration for Industrial Methanol Production From the Synthesis Gas

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Payam Parvasi ◽  
Seyyed Mohammad Jokar
Keyword(s):  
Methanol Synthesis ◽  
Radial Flow ◽  
Cooling Water ◽  
Packed Bed ◽  
Optimization Methods ◽  
Packed Bed Reactor ◽  
Flow Reactors ◽  
Methanol Production ◽  
Reactor Models ◽  
The Cost

In this work, the methanol synthesis on a commercial industrial catalyst in a novel cylindrical radial flow packed-bed reactor is investigated. The adiabatic and nonadiabatic cylindrical radial flow reactors were proposed and modeled in this research. The proposed configuration has been compared with conventional reactor for methanol production. It leads to higher methanol production and lower pressure drop, with the same catalyst consumption. Furthermore, the results show that the nonadiabatic radial flow packed-bed reactor has a higher methanol content compared with the adiabatic one. The improvement in methanol production was studied by optimizing the essential parameters such as inlet temperatures of the feed and cooling water as well as the number of cooling tubes. The nonlinearity and complexity of the reactor models make the traditional optimization methods ineffective and improbable. Therefore, the process was optimized by genetic algorithm (GA) method, which is one of the most powerful methods. The optimum values for the number of cooling tubes, feed and cooling water temperatures were 308, 507.6 K, and 522.43 K, respectively. The optimization results showed that a new reactor design could be proposed to reduce the cost of methanol synthesis.

scholarly journals Synthesis of Furfuryl Alcohol from Furfural: A Comparison between Batch and Continuous Flow Reactors

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1002 ◽  
Author(s):  
Maïté Audemar ◽  
Yantao Wang ◽  
Deyang Zhao ◽  
Sébastien Royer ◽  
François Jérôme ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Furfuryl Alcohol ◽  
Flow Reactor ◽  
Negative Impact ◽  
Batch Process ◽  
Metal Catalyst ◽  
Flow Reactors ◽  
Continuous Flow Reactors ◽  
Space Time Yield ◽  
The Stability

Furfural is a platform molecule obtained from hemicellulose. Among the products that can be produced from furfural, furfuryl alcohol is one of the most extensively studied. It is synthesized at an industrial scale in the presence of CuCr catalyst, but this process suffers from an environmental negative impact. Here, we demonstrate that a non-noble metal catalyst (Co/SiO2) was active (100% conversion of furfural) and selective (100% selectivity to furfuryl alcohol) in the hydrogenation of furfural to furfuryl alcohol at 150 °C under 20 bar of hydrogen. This catalyst was recyclable up to 3 cycles, and then the activity decreased. Thus, a comparison between batch and continuous flow reactors shows that changing the reactor type helps to increase the stability of the catalyst and the space-time yield. This study shows that using a continuous flow reactor can be a solution to the catalyst suffering from a lack of stability in the batch process.

Catalysis-in-a-Box: A Micro-flow Catalytic Reactor Integrated within a Gas Chromatograph for Automated Kinetic Measurements

2019 ◽  
Author(s):  
Gaurav Kumar ◽  
Hannah Bossert ◽  
Daniel McDonald ◽  
Anargyros Chatzidmitriou ◽  
M. Alexander Ardagh ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Packed Bed ◽  
Reaction Rates ◽  
Gas Chromatograph ◽  
Kinetic Measurements ◽  
Flow Reactors ◽  
Activation Barriers ◽  
Partial Pressures ◽  
Micro Flow ◽  
Kinetic Investigations

<p>The design and implementation of an autonomous micro-flow-reactor condensing conventional laboratory-scale analogues within a single gas chromatograph (GC) is reported, enabling the control of relevant parameters including reactor temperature and reactant partial pressures directly from the GC. Inquiries into the hydrodynamic behavior, temperature control, and heat/mass transfer were sought to evaluate the efficacy of the micro-flow-reactor for kinetic measurements. A combination of four Brønsted acid catalyzed probe reactions, namely the dehydration of ethanol, 2-propanol, 1-butanol, and the dehydra-decyclization of 2-methyltetrahydrofuran on a solid acid HZSM-5 (Si/Al 140), were carried out in the temperature range 403-543 K for the measurement of apparent reaction kinetics. Product selectivities, proton-normalized reaction rates, and apparent activation barriers were found to be in agreement with measurements performed in conventional packed bed flow reactors. The developed micro-flow-reactor is therefore intended to be used for kinetic investigations in vapor-phase catalytic chemistries, with the key benefits including automation and limited experimental equipment instrumentation.</p>

Immobilized Whole Cells as Effective Catalysts for Chiral Alcohol Production

2009 ◽  
Vol 62 (9) ◽  
pp. 1034 ◽  
Author(s):  
Jeck Fei Ng ◽  
Stephan Jaenicke
Keyword(s):  
Flow Reactor ◽  
Batch Reactor ◽  
Enantiomeric Excess ◽  
Lactobacillus Brevis ◽  
Packed Bed ◽  
Alginate Beads ◽  
Packed Bed Reactor ◽  
Process Conditions ◽  
Alcohol Production ◽  
Whole Cells

Recombinant Escherichia coli overexpressing the gene LbADH, which encodes for an alcohol dehydrogenase from Lactobacillus brevis, was successfully transformed and cultured. The cells are able to catalyze the reduction of pro-chiral ketones, e.g. ethyl acetoacetate into R-(–)ethyl hydroxybutyrate (EHB) with high conversion and enantiomeric excess >99%. Immobilizing the whole cells in alginate beads leads to a catalyst with improved stability and ease of handling while maintaining the high activity of the free cells. The whole-cell catalyst was tested in a stirred batch reactor (CSTR) and in a continuously operated packed-bed reactor. An Mg2+ concentration of 2 mM was crucial for maintaining the activity of the biocatalyst. After a partial optimization of the process conditions, a productivity of 1.4 gEHB gwcw–1 h–1 could be maintained in a continuous flow reactor over a prolonged period of time.

scholarly journals Co-immobilized Alcohol Dehydrogenase and Glucose Dehydrogenase with Resin Extraction for Continuous Production of Chiral Diaryl Alcohol

2021 ◽  
Author(s):  
Jieyu Zhou ◽  
Yanfei Wu ◽  
Qingye Zhang ◽  
Guochao Xu ◽  
YE NI
Keyword(s):  
Alcohol Dehydrogenase ◽  
Selective Adsorption ◽  
Glucose Dehydrogenase ◽  
Continuous Production ◽  
Porous Ceramic ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Affinity Tag ◽  
Composite Beads ◽  
Space Time Yield

Abstract Ni2+-functionalized porous ceramic/agarose composite beads (Ni-NTA Cerose) can be used as carrier materials to immobilize enzymes harboring a metal affinity tag. Here, a 6×His-tag fusion alcohol dehydrogenase Mu-S5 and glucose dehydrogenase from Bacillus megaterium (BmGDH) were co-immobilized on Ni-NTA Cerose to construct a packed bed reactor (PBR) for the continuous synthesis of the chiral intermediate (S)-(4-chlorophenyl)-(pyridin-2-yl) methanol [(S)-CPMA]. NADPH recycling and in situ product adsorption was achieved simultaneously by assembling a D101 macroporous resin column after the PBR. Using an optimum enzyme activity ration of 2:1 (Mu-S5: BmGDH) and hydroxypropyl-β-cyclodextrin as co-solvent, a space-time yield of 1,560 g/(L·d) could be achieved in the first three days at a flow rate of 5 mL/min and substrate concentration of 10 mM. With simplified selective adsorption and extraction procedures, (S)-CPMA was obtained in 84% isolated yield.

scholarly journals Catalytic hydrogenation of N-4-nitrophenyl nicotinamide in a micro-packed bed reactor

2018 ◽  
Vol 20 (4) ◽  
pp. 886-893 ◽  
Author(s):  
Cuixian Yang ◽  
Andrew R. Teixeira ◽  
Yanxiang Shi ◽  
Stephen C. Born ◽  
Hongkun Lin ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Flow Chemistry ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Micro Flow ◽  
Pharmaceutical Production

Recent advancements in micro-flow technologies and a drive toward more efficient, greener and safer processes have led to a renaissance in flow-chemistry for pharmaceutical production.

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