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Author | van ‘t Veer, K.; Reniers, F.; Bogaerts, A. | ||||
Title | Zero-dimensional modeling of unpacked and packed bed dielectric barrier discharges: the role of vibrational kinetics in ammonia synthesis | Type | A1 Journal article | ||
Year | 2020 | Publication | Plasma Sources Science & Technology | Abbreviated Journal | Plasma Sources Sci T |
Volume | 29 | Issue | 4 | Pages | 045020 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | We present a zero-dimensional plasma kinetics model, including both surface and gas phase kinetics, to determine the role of vibrationally excited states in plasma-catalytic ammonia synthesis. We defined a new method to systematically capture the conditions of dielectric barrier discharges (DBDs), including those found in packed bed DBDs. We included the spatial and temporal nature of such discharges by special consideration of the number of micro-discharges in the model. We introduce a parameter that assigns only a part of the plasma power to the microdischarges, to scale the model conditions from filamentary to uniform plasma. Because of the spatial and temporal behaviour of the micro-discharges, not all micro-discharges occurring in the plasma reactor during a certain gas residence time are affecting the molecules. The fraction of power considered in the model ranges from 0.005 %, for filamentary plasma, to 100 %, for uniform plasma. If vibrational excitation is included in the plasma chemistry, these different conditions, however, yield an ammonia density that is only varying within one order of magnitude. At only 0.05 % of the power put into the uniform plasma component, a model neglecting vibrational excitation clearly does not result in adequate amounts of ammonia. Thus, our new model, which accounts for the concept in which not all the power is deposited by the micro-discharges, but some part may also be distributed in between them, suggests that vibrational kinetic processes are really important in (packed bed) DBDs. Indeed, vibrational excitation takes place in both the uniform plasma between the micro-discharges and in the strong micro-discharges, and is responsible for an increased N2 dissociation rate. This is shown here for plasma-catalytic ammonia synthesis, but might also be valid for other gas conversion applications. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000570241500001 | Publication Date | 2020-04-09 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1361-6595 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.8 | Times cited | Open Access | ||
Notes | This research was supported by the Excellence of Science FWO-FNRS project (FWO grant ID GoF9618n, EOS ID 30505023). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. The authors would also like to thank Dr. Fatme Jardali for the discussions on plasma kinetic modelling and Dr. Jungmi Hong and Dr. Anthony B. Murphy for their aid in the calculation of the diffusion coefficients. | Approved | Most recent IF: 3.8; 2020 IF: 3.302 | ||
Call Number | PLASMANT @ plasmant @c:irua:168097 | Serial | 6359 | ||
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Author | van ‘t Veer, K.; van Alphen, S.; Remy, A.; Gorbanev, Y.; De Geyter, N.; Snyders, R.; Reniers, F.; Bogaerts, A. | ||||
Title | Spatially and temporally non-uniform plasmas: microdischarges from the perspective of molecules in a packed bed plasma reactor | Type | A1 Journal article | ||
Year | 2021 | Publication | Journal Of Physics D-Applied Physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 54 | Issue | 17 | Pages | 174002 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Dielectric barrier discharges (DBDs) typically operate in the filamentary regime and thus exhibit great spatial and temporal non-uniformity. In order to optimize DBDs for various applications, such as in plasma catalysis, more fundamental insight is needed. Here, we consider how the millions of microdischarges, characteristic for a DBD, influence individual gas molecules. We use a Monte Carlo approach to determine the number of microdischarges to which a single molecule would be exposed, by means of particle tracing simulations through a full-scale packed bed DBD reactor, as well as an empty DBD reactor. We find that the fraction of microdischarges to which the molecules are exposed can be approximated as the microdischarge volume over the entire reactor gas volume. The use of this concept provides good agreement between a plasma-catalytic kinetics model and experiments for plasma-catalytic NH3 synthesis. We also show that the concept of the fraction of microdischarges indicates the efficiency by which the plasma power is transferred to the gas molecules. This generalised concept is also applicable for other spatially and temporally non-uniform plasmas. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000618776000001 | Publication Date | 2021-04-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-3727 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.588 | Times cited | Open Access | OpenAccess | |
Notes | Excellence of Science FWO-FNRS project, FWO grant ID GoF9618n ; Flemish Government, project P2C (HBC.2019.0108) ; H2020 European Research Council, grant agreement No 810182 – SCOPE ERC Synergy pr ; This research was supported by the Excellence of Science FWO-FNRS project (FWO Grant ID GoF9618n, EOS ID 30505023), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No 810182—SCOPE ERC Synergy project) and by the Flemish Government through the Moonshot cSBO project P2C (HBC. 2019.0108). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. The authors would also like to thank Hamid Ahmadi Eshtehardi for discussions on the plasma-kinetic DBD model and Yannick Engelmann for discussions on the surface kinetics model. | Approved | Most recent IF: 2.588 | ||
Call Number | PLASMANT @ plasmant @c:irua:175878 | Serial | 6674 | ||
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Author | Rouwenhorst, K.H.R.; Engelmann, Y.; van ‘t Veer, K.; Postma, R.S.; Bogaerts, A.; Lefferts, L. | ||||
Title | Plasma-driven catalysis: green ammonia synthesis with intermittent electricity | Type | A1 Journal article | ||
Year | 2020 | Publication | Green Chemistry | Abbreviated Journal | Green Chem |
Volume | 22 | Issue | 19 | Pages | 6258-6287 |
Keywords | A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Movement Antwerp (MOVANT) | ||||
Abstract | Ammonia is one of the most produced chemicals, mainly synthesized from fossil fuels for fertilizer applications. Furthermore, ammonia may be one of the energy carriers of the future, when it is produced from renewable electricity. This has spurred research on alternative technologies for green ammonia production. Research on plasma-driven ammonia synthesis has recently gained traction in academic literature. In the current review, we summarize the literature on plasma-driven ammonia synthesis. We distinguish between mechanisms for ammonia synthesis in the presence of a plasma, with and without a catalyst, for different plasma conditions. Strategies for catalyst design are discussed, as well as the current understanding regarding the potential plasma-catalyst synergies as function of the plasma conditions and their implications on energy efficiency. Finally, we discuss the limitations in currently reported models and experiments, as an outlook for research opportunities for further unravelling the complexities of plasma-catalytic ammonia synthesis, in order to bridge the gap between the currently reported models and experimental results. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000575015700002 | Publication Date | 2020-09-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1463-9262 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.8 | Times cited | 4 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 9.8; 2020 IF: 9.125 | ||
Call Number | PLASMANT @ plasmant @c:irua:172671 | Serial | 6430 | ||
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Author | Eshtehardi, H.A.; Van ‘t Veer, K.; Delplancke, M.-P.; Reniers, F.; Bogaerts, A. | ||||
Title | Postplasma Catalytic Model for NO Production: Revealing the Underlying Mechanisms to Improve the Process Efficiency | Type | A1 Journal article | ||
Year | 2023 | Publication | ACS Sustainable Chemistry and Engineering | Abbreviated Journal | |
Volume | 11 | Issue | 5 | Pages | 1720-1733 |
Keywords | A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Plasma catalysis is emerging for plasma-assisted gas conversion processes. However, the underlying mechanisms of plasma catalysis are poorly understood. In this work, we present a 1D heterogeneous catalysis model with axial dispersion (i.e., accounting for back-mixing and molecular diffusion of fluid elements in the process stream in the axial direction), for plasma-catalytic NO production from N2/O2 mixtures. We investigate the concentration and reaction rates of each species formed as a function of time and position across the catalyst, in order to determine the underlying mechanisms. To obtain insights into how the performance of the process can be further improved, we also study how changes in the postplasma gas flow composition entering the catalyst bed and in the operation conditions of the catalytic stage affect the performance of NO production. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000926412800001 | Publication Date | 2023-02-06 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2168-0485 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.4 | Times cited | Open Access | OpenAccess | |
Notes | This research was supported by the Excellence of Science FWO-FNRS project (FWO grant ID GoF9618n, EOS ID 30505023) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 810182 − SCOPE ERC Synergy project). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. | Approved | Most recent IF: 8.4; 2023 IF: 5.951 | ||
Call Number | PLASMANT @ plasmant @c:irua:195377 | Serial | 7257 | ||
Permanent link to this record | |||||
Author | Eshtehardi, H.A.; Van ‘t Veer, K.; Delplancke, M.-P.; Reniers, F.; Bogaerts, A. | ||||
Title | Postplasma Catalytic Model for NO Production: Revealing the Underlying Mechanisms to Improve the Process Efficiency | Type | A1 Journal article | ||
Year | 2023 | Publication | ACS Sustainable Chemistry and Engineering | Abbreviated Journal | |
Volume | 11 | Issue | 5 | Pages | 1720-1733 |
Keywords | A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Plasma catalysis is emerging for plasma-assisted gas conversion processes. However, the underlying mechanisms of plasma catalysis are poorly understood. In this work, we present a 1D heterogeneous catalysis model with axial dispersion (i.e., accounting for back-mixing and molecular diffusion of fluid elements in the process stream in the axial direction), for plasma-catalytic NO production from N2/O2 mixtures. We investigate the concentration and reaction rates of each species formed as a function of time and position across the catalyst, in order to determine the underlying mechanisms. To obtain insights into how the performance of the process can be further improved, we also study how changes in the postplasma gas flow composition entering the catalyst bed and in the operation conditions of the catalytic stage affect the performance of NO production. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000926412800001 | Publication Date | 2023-02-06 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2168-0485 | ISBN | Additional Links | UA library record; WoS full record | |
Impact Factor | 8.4 | Times cited | Open Access | OpenAccess | |
Notes | Fonds Wetenschappelijk Onderzoek, 30505023 GoF9618n ; Fonds De La Recherche Scientifique – FNRS, 30505023 GoF9618n ; H2020 European Research Council, 810182 ; | Approved | Most recent IF: 8.4; 2023 IF: 5.951 | ||
Call Number | PLASMANT @ plasmant @c:irua:195377 | Serial | 7258 | ||
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Author | van ‘t Veer, K.; Engelmann, Y.; Reniers, F.; Bogaerts, A. | ||||
Title | Plasma-Catalytic Ammonia Synthesis in a DBD Plasma: Role of Microdischarges and Their Afterglows | Type | A1 Journal article | ||
Year | 2020 | Publication | Journal Of Physical Chemistry C | Abbreviated Journal | J Phys Chem C |
Volume | 124 | Issue | 42 | Pages | 22871-22883 |
Keywords | A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Movement Antwerp (MOVANT) | ||||
Abstract | Plasma-catalytic ammonia synthesis is receiving ever increasing attention, especially in packed bed dielectric barrier discharge (DBD) reactors. The latter typically operate in the filamentary regime when used for gas conversion applications. While DBDs are in principle well understood and already applied in the industry, the incorporation of packing materials and catalytic surfaces considerably adds to the complexity of the plasma physics and chemistry governing the ammonia formation. We employ a plasma kinetics model to gain insights into the ammonia formation mechanisms, paying special attention to the role of filamentary microdischarges and their afterglows. During the microdischarges, the synthesized ammonia is actually decomposed, but the radicals created upon electron impact dissociation of N2 and H2 and the subsequent catalytic reactions cause a net ammonia gain in the afterglows of the microdischarges. Under our plasma conditions, electron impact dissociation of N2 in the gas phase followed by the adsorption of N atoms is identified as a rate-limiting step, instead of dissociative adsorption of N2 on the catalyst surface. Both elementary Eley−Rideal and Langmuir−Hinshelwood reaction steps can be found important in plasma-catalytic NH3 synthesis. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000585970300002 | Publication Date | 2020-10-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1932-7447 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.7 | Times cited | Open Access | OpenAccess | |
Notes | Fonds Wetenschappelijk Onderzoek, 30505023 GoF9618n ; Fonds De La Recherche Scientifique – FNRS, 30505023 GoF9618n ; H2020 European Research Council, 810182 ;This research was supported by the Excellence of Science FWOFNRS project (FWO grant ID GoF9618n, EOS ID 30505023) and by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no 810182-SCOPE ERC Synergy project). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. The authors would also like to thank Järi Van den Hoek and Dr. Yury Gorbanev for providing the experimentally measured electrical characteristics and Dr. Fatme Jardali for creating the TOC graphics. | Approved | Most recent IF: 3.7; 2020 IF: 4.536 | ||
Call Number | PLASMANT @ plasmant @c:irua:173587 | Serial | 6428 | ||
Permanent link to this record |