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Doering M, Trinkies LL, Kieninger J, Kraut M, Rupitsch SJ, Dittmeyer R, Urban GA, Weltin A. In Situ Performance Monitoring of Electrochemical Oxygen and Hydrogen Peroxide Sensors in an Additively Manufactured Modular Microreactor. ACS OMEGA 2024; 9:19700-19711. [PMID: 38708269 PMCID: PMC11064172 DOI: 10.1021/acsomega.4c02210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 03/21/2024] [Accepted: 03/27/2024] [Indexed: 05/07/2024]
Abstract
Miniaturized and microstructured reactors in process engineering are essential for a more decentralized, flexible, sustainable, and resilient chemical production. Modern, additive manufacturing methods for metals enable complex reactor-geometries, increased functionality, and faster design iterations, a clear advantage over classical subtractive machining and polymer-based approaches. Integrated microsensors allow online, in situ process monitoring to optimize processes like the direct synthesis of hydrogen peroxide. We developed a modular tube-in-tube membrane reactor fabricated from stainless steel via 3D printing by laser powder bed fusion of metals (PBF-LB/M). The reactor concept enables the spatially separated dosage and resaturation of two gaseous reactants across a membrane into a liquid process medium. Uniquely, we integrated platinum-based electrochemical sensors for the online detection of analytes to reveal the dynamics inside the reactor. An advanced chronoamperometric protocol combined the simultaneous concentration measurement of hydrogen peroxide and oxygen with monitoring of the sensor performance and self-calibration in long-term use. We demonstrated the highly linear and sensitive monitoring of hydrogen peroxide and dissolved oxygen entering the liquid phase through the membrane. Our measurements delivered important real-time insights into the dynamics of the concentrations in the reactor, highlighting the power of electrochemical sensors applied in process engineering. We demonstrated the stable continuous measurement over 1 week and estimated the sensor lifetime for months in the acidic process medium. Our approach combines electrochemical sensors for process monitoring with advanced, additively manufactured stainless steel membrane microreactors, supporting the power of sensor-equipped microreactors as contributors to the paradigm change in process engineering and toward a greener chemistry.
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Affiliation(s)
- Moritz Doering
- Laboratory
for Sensors, IMTEK − Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
- Laboratory
for Electrical Instrumentation and Embedded Systems, IMTEK −
Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Laura L. Trinkies
- Institute
of Micro Process Engineering (IMVT), Karlsruhe
Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Jochen Kieninger
- Laboratory
for Sensors, IMTEK − Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
- Laboratory
for Electrical Instrumentation and Embedded Systems, IMTEK −
Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Manfred Kraut
- Institute
of Micro Process Engineering (IMVT), Karlsruhe
Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Stefan J. Rupitsch
- Laboratory
for Electrical Instrumentation and Embedded Systems, IMTEK −
Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Roland Dittmeyer
- Institute
of Micro Process Engineering (IMVT), Karlsruhe
Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Gerald A. Urban
- Laboratory
for Sensors, IMTEK − Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Andreas Weltin
- Laboratory
for Sensors, IMTEK − Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
- Laboratory
for Electrical Instrumentation and Embedded Systems, IMTEK −
Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
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Al-Sulaimi S, Kushwah R, Abdullah Alsibani M, El Jery A, Aldrdery M, Ashraf GA. Emerging Developments in Separation Techniques and Analysis of Chiral Pharmaceuticals. Molecules 2023; 28:6175. [PMID: 37687004 PMCID: PMC10489017 DOI: 10.3390/molecules28176175] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/05/2023] [Accepted: 08/14/2023] [Indexed: 09/10/2023] Open
Abstract
Chiral separation, the process of isolating enantiomers from a racemic mixture, holds paramount importance in diverse scientific disciplines. Using chiral separation methods like chromatography and electrophoresis, enantiomers can be isolated and characterized. This study emphasizes the significance of chiral separation in drug development, quality control, environmental analysis, and chemical synthesis, facilitating improved therapeutic outcomes, regulatory compliance, and enhanced industrial processes. Capillary electrophoresis (CE) has emerged as a powerful technique for the analysis of chiral drugs. This review also highlights the significance of CE in chiral drug analysis, emphasizing its high separation efficiency, rapid analysis times, and compatibility with other detection techniques. High-performance liquid chromatography (HPLC) has become a vital technique for chiral drugs analysis. Through the utilization of a chiral stationary phase, HPLC separates enantiomers based on their differential interactions, allowing for the quantification of individual enantiomeric concentrations. This study also emphasizes the significance of HPLC in chiral drug analysis, highlighting its excellent resolution, sensitivity, and applicability. The resolution and enantiomeric analysis of nonsteroidal anti-inflammatory drugs (NSAIDs) hold great importance due to their chiral nature and potential variations in pharmacological effects. Several studies have emphasized the significance of resolving and analyzing the enantiomers of NSAIDs. Enantiomeric analysis provides critical insights into the pharmacokinetics, pharmacodynamics, and potential interactions of NSAIDs, aiding in drug design, optimization, and personalized medicine for improved therapeutic outcomes and patient safety. Microfluidics systems have revolutionized chiral separation, offering miniaturization, precise fluid control, and high throughput. Integration of microscale channels and techniques provides a promising platform for on-chip chiral analysis in pharmaceuticals and analytical chemistry. Their applications in techniques such as high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC) offer improved resolution and faster analysis times, making them valuable tools for enantiomeric analysis in pharmaceutical, environmental, and biomedical research.
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Affiliation(s)
- Sulaiman Al-Sulaimi
- Department of Biological Science and Chemistry, University of Nizwa, Nizwa 611, Oman; (S.A.-S.); (R.K.); (M.A.A.)
| | - Reveka Kushwah
- Department of Biological Science and Chemistry, University of Nizwa, Nizwa 611, Oman; (S.A.-S.); (R.K.); (M.A.A.)
| | - Mohammed Abdullah Alsibani
- Department of Biological Science and Chemistry, University of Nizwa, Nizwa 611, Oman; (S.A.-S.); (R.K.); (M.A.A.)
| | - Atef El Jery
- Department of Chemical Engineering, College of Engineering, King Khalid University, Abha 61411, Saudi Arabia
| | - Moutaz Aldrdery
- Department of Chemical Engineering, College of Engineering, King Khalid University, Abha 61411, Saudi Arabia
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Zhang C, Huang M, Yin J, Lou F, Chen X, Zhang J. Green and practical TEMPO-functionalized activated carbon as a durable catalyst for continuous aerobic oxidation of alcohols. J Catal 2022. [DOI: 10.1016/j.jcat.2022.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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4
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Siddiquee MN, Hossain MM, Nazemifard N. Liquid Phase Oxidation of Hydrocarbons to High-Value Chemicals in Microfluidic Reactors - Prospects and Challenges. CHEM REC 2022; 22:e202200022. [PMID: 35502847 DOI: 10.1002/tcr.202200022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/28/2022] [Indexed: 11/05/2022]
Abstract
Liquid phase oxidation (LPO) of hydrocarbon is an industrially important process to produce petrochemicals and pharmaceuticals. It follows a free radical path having initiation, propagation and termination. The initiation step is slow while the propagation and termination steps are fast. The main challenge of such process is to control product selectivity at an appreciable conversion level. With the advancement of microfluidic reactor technology, it is possible to control the free radical steps. The present contribution critically reviewed the reaction engineering aspects of LPO of hydrocarbon, the influence of microfluidic reactor design and operation on reaction mechanism, conversion and product selectivity. It also outlines the challenges associated with microfluidic reactor operation, and prospects to apply the understanding from microfluidic reactors in few sectors. The understanding from the free radical oxidation process can also be applied to any other free radical processes.
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Affiliation(s)
- Muhammad N Siddiquee
- Department of Chemical Engineering, King Fahd University of Petroleum & Minerals (KFUPM), KFUPM Box 5050, Dhahran, 31261, Saudi Arabia.,Interdisciplinary Research Center for Refining & Advanced Chemicals (IRC-RAC), King Fahd University of Petroleum & Minerals (KFUPM), KFUPM Box 5050, Dhahran, 31261, Saudi Arabia
| | - Mohammad M Hossain
- Department of Chemical Engineering, King Fahd University of Petroleum & Minerals (KFUPM), KFUPM Box 5050, Dhahran, 31261, Saudi Arabia.,Interdisciplinary Research Center for Refining & Advanced Chemicals (IRC-RAC), King Fahd University of Petroleum & Minerals (KFUPM), KFUPM Box 5050, Dhahran, 31261, Saudi Arabia
| | - Neda Nazemifard
- Department of Chemical Engineering, University of Alberta, 9211-116th Street, Edmonton, AB, T6G 1H9, Canada
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Fariba Beigmoradi, Hadi Beitollahi. MXene/La3+ Doped ZnO/Hb Nanocomposite Modified Glassy Carbon Electrode as Novel Voltammetric Sensor for Determination of Hydrogen Peroxide. SURFACE ENGINEERING AND APPLIED ELECTROCHEMISTRY 2021. [DOI: 10.3103/s106837552106003x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Hunt G, Karimi N, Mehdizadeh A. Intensification of ultra-lean catalytic combustion of methane in microreactors by boundary layer interruptions – A computational study. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2021.116730] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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7
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Exothermic reactions on the heterogeneous catalysts: Features of research and implementation. Chem Eng Res Des 2021. [DOI: 10.1016/j.cherd.2021.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Urban S, Deschner BJ, Trinkies LL, Kieninger J, Kraut M, Dittmeyer R, Urban GA, Weltin A. In Situ Mapping of H 2, O 2, and H 2O 2 in Microreactors: A Parallel, Selective Multianalyte Detection Method. ACS Sens 2021; 6:1583-1594. [PMID: 33481585 DOI: 10.1021/acssensors.0c02509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Determining local concentrations of the analytes in state-of-the-art microreactors is essential for the development of optimized and safe processes. However, the selective, parallel monitoring of all relevant reactants and products in a multianalyte environment is challenging. Electrochemical microsensors can provide unique information on the reaction kinetics and overall performance of the hydrogen peroxide synthesis process in microreactors, thanks to their high spatial and temporal resolution and their ability to measure in situ, in contrast to other techniques. We present a chronoamperometric approach which allows the selective detection of the dissolved gases hydrogen and oxygen and their reaction product hydrogen peroxide on the same platinum microelectrode in an aqueous electrolyte. The method enables us to obtain the concentration of each analyte using three specific potentials and to subtract interfering currents from the mixed signal. While hydrogen can be detected independently, no potentials can be found for a direct, selective measurement of oxygen and hydrogen peroxide. Instead, it was found that for combined signals, the individual contribution of all analytes superimposes linearly additive. We showed that the concentrations determined from the subtracted signals correlate very well with results obtained without interfering analytes present. For the first time, this approach allowed the mapping of the distribution of the analytes hydrogen, oxygen, and hydrogen peroxide inside a multiphase membrane microreactor, paving the way for online process control.
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Affiliation(s)
- Sebastian Urban
- Laboratory for Sensors, IMTEK−Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Benedikt J. Deschner
- Institute for Micro Process Engineering (IMVT), Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Laura L. Trinkies
- Institute for Micro Process Engineering (IMVT), Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Jochen Kieninger
- Laboratory for Sensors, IMTEK−Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Manfred Kraut
- Institute for Micro Process Engineering (IMVT), Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Roland Dittmeyer
- Institute for Micro Process Engineering (IMVT), Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Gerald A. Urban
- Laboratory for Sensors, IMTEK−Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Andreas Weltin
- Laboratory for Sensors, IMTEK−Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
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Microsensor Electrodes for 3D Inline Process Monitoring in Multiphase Microreactors. SENSORS 2020; 20:s20174876. [PMID: 32872213 PMCID: PMC7506731 DOI: 10.3390/s20174876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/19/2020] [Accepted: 08/26/2020] [Indexed: 01/01/2023]
Abstract
We present an electrochemical microsensor for the monitoring of hydrogen peroxide direct synthesis in a membrane microreactor environment by measuring the hydrogen peroxide and oxygen concentrations. In prior work, for the first time, we performed in situ measurements with electrochemical microsensors in a microreactor setup. However, the sensors used were only able to measure at the bottom of the microchannel. Therefore, only a limited assessment of the gas distribution and concentration change over the reaction channel dimensions was possible because the dissolved gases entered the reactor through a membrane at the top of the channel. In this work, we developed a new fabrication process to allow the sensor wires, with electrodes at the tip, to protrude from the sensor housing into the reactor channel. This enables measurements not only at the channel bottom, but also along the vertical axis within the channel, between the channel wall and membrane. The new sensor design was integrated into a multiphase microreactor and calibrated for oxygen and hydrogen peroxide measurements. The importance of measurements in three dimensions was demonstrated by the detection of strongly increased gas concentrations towards the membrane, in contrast to measurements at the channel bottom. These findings allow a better understanding of the analyte distribution and diffusion processes in the microreactor channel as the basis for process control of the synthesis reaction.
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Design, Fundamental Principles of Fabrication and Applications of Microreactors. Processes (Basel) 2020. [DOI: 10.3390/pr8080891] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This study highlights the development of small-scale reactors, in the form of microstructures with microchannel networking. Microreactors have achieved an impressive reputation, regarding chemical synthesis ability and their applications in the engineering, pharmaceutical, and biological fields. This review elaborates on the fabrication, construction, and schematic fundamentals in the design of the microreactors and microchannels. The materials used in the fabrication or construction of the microreactors include silicon, polymer, and glass. A general review of the application of microreactors in medical, biological, and engineering fields is carried out and significant improvements in these areas are reported. Finally, we highlight the flow patterns, mixing, and scaling-up of multiphase microreactor developments, with emphasis on the more significant industrial applications.
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Chen J, Song W, Xu D. Compact Steam-Methane Reforming for the Production of Hydrogen in Continuous Flow Microreactor Systems. ACS OMEGA 2019; 4:15600-15614. [PMID: 31572861 PMCID: PMC6761760 DOI: 10.1021/acsomega.9b02063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
The implementation of fuel cell deployment requires efficient conversion of fuels into hydrogen in a distributed energy system. Fortunately, continuous flow and microreactor technology provide unique opportunities for the portable production of hydrogen. This study focuses on determining the operation space for a thermally integrated methane reforming system, thereby providing a theoretical basis for the design and optimization of such systems. The steam-methane reforming over rhodium coupled with methane combustion over platinum in a thermally integrated microchannel reactor arranged with rectangular-shaped protuberances was studied numerically in order to improve its operability and stability. Computational fluid dynamic simulations were carried out with detailed reaction mechanisms to identify conditions for the maximum hydrogen yield and the highest output power. Various operating lines were presented, and various performance metrics were evaluated accordingly. The results indicated that the efficient production of hydrogen is made possible through improving transport performance for highly active catalysts. The flow disturbance elements designed for the reactor are of great benefit to intensification of the reforming process. There exists a trade-off between fuel utilization and output power. Autothermal operation advantages from improved transport performance in small physical dimensions were demonstrated for the system, but careful thermal management is always necessary to ensure its efficient and stable operation. The thermal conductivity of the wall separating the exothermic and endothermic reactions plays a significant role in determining the performance of the system. Highly active catalysts are required to intensify the overall reforming process and to achieve efficient thermal management. Adjustment of fluid velocities can serve as a convenient means to achieve efficient operation of the system.
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Hommes A, Heeres HJ, Yue J. Catalytic Transformation of Biomass Derivatives to Value‐Added Chemicals and Fuels in Continuous Flow Microreactors. ChemCatChem 2019. [DOI: 10.1002/cctc.201900807] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Arne Hommes
- Department of Chemical Engineering Engineering and Technology Institute GroningenUniversity of Groningen Nijenborgh 4 Groningen 9747 AG The Netherlands
| | - Hero Jan Heeres
- Department of Chemical Engineering Engineering and Technology Institute GroningenUniversity of Groningen Nijenborgh 4 Groningen 9747 AG The Netherlands
| | - Jun Yue
- Department of Chemical Engineering Engineering and Technology Institute GroningenUniversity of Groningen Nijenborgh 4 Groningen 9747 AG The Netherlands
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13
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Dai X, Zhou W, Yang S, Sun F, Qian J, He M, Chen Q. Microchannel process for phenol production via the cleavage of cumene hydroperoxide. Chem Eng Sci 2019. [DOI: 10.1016/j.ces.2019.01.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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Brandner JJ. In-Situ Measurements in Microscale Gas Flows-Conventional Sensors or Something Else? MICROMACHINES 2019; 10:E292. [PMID: 31035685 PMCID: PMC6562918 DOI: 10.3390/mi10050292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/24/2019] [Accepted: 04/26/2019] [Indexed: 12/03/2022]
Abstract
Within the last few decades miniaturization has a driving force in almost all areas of technology, leading to a tremendous intensification of systems and processes. Information technology provides now data density several orders of magnitude higher than a few years ago, and the smartphone technology includes, as well the simple ability to communicate with others, features like internet, video and music streaming, but also implementation of the global positioning system, environment sensors or measurement systems for individual health. So-called wearables are everywhere, from the physio-parameter sensing wrist smart watch up to the measurement of heart rates by underwear. This trend holds also for gas flow applications, where complex flow arrangements and measurement systems formerly designed for a macro scale have been transferred into miniaturized versions. Thus, those systems took advantage of the increased surface to volume ratio as well as of the improved heat and mass transfer behavior of miniaturized equipment. In accordance, disadvantages like gas flow mal-distribution on parallelized mini- or micro tubes or channels as well as increased pressure losses due to the minimized hydraulic diameters and an increased roughness-to-dimension ratio have to be taken into account. Furthermore, major problems are arising for measurement and control to be implemented for in-situ and/or in-operando measurements. Currently, correlated measurements are widely discussed to obtain a more comprehensive view to a process by using a broad variety of measurement techniques complementing each other. Techniques for correlated measurements may include commonly used techniques like thermocouples or pressure sensors as well as more complex systems like gas chromatography, mass spectrometry, infrared or ultraviolet spectroscopy and many others. Some of these techniques can be miniaturized, some of them cannot yet. Those should, nevertheless, be able to conduct measurements at the same location and the same time, preferably in-situ and in-operando. Therefore, combinations of measurement instruments might be necessary, which will provide complementary techniques for accessing local process information. A recently more intensively discussed additional possibility is the application of nuclear magnetic resonance (NMR) systems, which might be useful in combination with other, more conventional measurement techniques. NMR is currently undergoing a tremendous change from large-scale to benchtop measurement systems, and it will most likely be further miniaturized. NMR allows a multitude of different measurements, which are normally covered by several instruments. Additionally, NMR can be combined very well with other measurement equipment to perform correlative in-situ and in-operando measurements. Such combinations of several instruments would allow us to retrieve an "information cloud" of a process. This paper will present a view of some common measurement techniques and the difficulties of applying them on one hand in a miniaturized scale, and on the other hand in a correlative mode. Basic suggestions to achieve the above-mentioned objective by a combination of different methods including NMR will be given.
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Affiliation(s)
- Juergen J Brandner
- Staff Position Microstructures and Process Sensors (MPS), Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
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Sofack Kreutzer J, Vanoye L, Guicheret B, Philippe R, Metay E, Duclos MC, Lemaire M, De Bellefon C, Fongarland P, Favre-Réguillon A. Continuous flow aerobic alcohol oxidation using a heterogeneous Ru 0 catalyst. REACT CHEM ENG 2019. [DOI: 10.1039/c8re00212f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Stable Ru0 on γ-Al2O3 has been used for the selective aerobic oxidation of benzyl alcohol in flow.
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Rossetti I. Continuous flow (micro-)reactors for heterogeneously catalyzed reactions: Main design and modelling issues. Catal Today 2018. [DOI: 10.1016/j.cattod.2017.09.040] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Yue J. Multiphase flow processing in microreactors combined with heterogeneous catalysis for efficient and sustainable chemical synthesis. Catal Today 2018. [DOI: 10.1016/j.cattod.2017.09.041] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Miura H, Bon V, Senkovska I, Ehrling S, Watanabe S, Ohba M, Kaskel S. Tuning the gate-opening pressure and particle size distribution of the switchable metal-organic framework DUT-8(Ni) by controlled nucleation in a micromixer. Dalton Trans 2018; 46:14002-14011. [PMID: 28976513 DOI: 10.1039/c7dt02809a] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Controlled nucleation in a micromixer and further crystal growth were used to synthesize Ni2(2,6-ndc)2dabco (2,6-ndc - 2,6-naphthalenedicarboxylate, dabco - 1,4-diazabicyclo[2.2.2]octane), also termed DUT-8(Ni) (DUT = Dresden University of Technology), with narrow particle size distribution in a range of a few nm to several μm. The crystal size was found to significantly affect the switching characteristics, in particular the gate opening pressure in nitrogen adsorption isotherms at 77 K for this highly porous and flexible network. Below a critical size of about 500 nm, a type Ia isotherm typical of rigid MOFs is observed, while above approximately 1000 nm a pronounced gating behaviour is detected, starting at p/p0 = 0.2. With increasing crystal size this transition gate becomes steeper indicating a more uniform distribution of activation energies within the crystal ensemble. At an intermediate size (500-1000 nm), the DUT-8(Ni) crystals close during activation but cannot be reopened by nitrogen at 77 K possibly indicating monodomain switching.
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Affiliation(s)
- Hiroki Miura
- Department of Inorganic Chemistry, Technische Universität Dresden, Bergstrasse 66, D-01062 Dresden, Germany.
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Hofmann S, Turek T. Process Intensification of n
-Butane Oxidation to Maleic Anhydride in a Millistructured Reactor. Chem Eng Technol 2017. [DOI: 10.1002/ceat.201700093] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sebastian Hofmann
- Clausthal University of Technology; Institute of Chemical and Electrochemical Process Engineering; Leibnizstraße 17 38678 Clausthal-Zellerfeld Germany
| | - Thomas Turek
- Clausthal University of Technology; Institute of Chemical and Electrochemical Process Engineering; Leibnizstraße 17 38678 Clausthal-Zellerfeld Germany
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Vessally E, Ghasemisarabbadeih M, Ekhteyari Z, Hosseinzadeh-Khanmiri R, Ghorbani-Kalhor E, Ejlali L. Platinum nanoparticles supported on polymeric ionic liquid functionalized magnetic silica: effective and reusable heterogeneous catalysts for the selective oxidation of alcohols in water. RSC Adv 2016. [DOI: 10.1039/c6ra16851e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In this manuscript, we demonstrate that functionalized magnetic silica nanoparticles are efficient and recyclable catalysts for the selective, aerobic oxidation of various primary and secondary alcohols.
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Affiliation(s)
| | | | | | | | | | - Ladan Ejlali
- Department of Chemistry
- Islamic Azad University
- Tabriz
- Iran
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