NANOlab Center of Excellence literature database -- Query Results

	NANOlab Center of Excellence literature database Home \| Show All \| Simple Search \| Advanced Search	Login Quick Search: Field: contains: ...
	1–6 of 6 records found matching your query (RSS \| history):

Select All Deselect All

<< 1 >>

List View

Citations

Details

	Records
	Author	Vermeiren, V.; Bogaerts, A.
	Title	Plasma-Based CO₂Conversion: To Quench or Not to Quench?			Type	A1 Journal article
	Year	2020	Publication	Journal Of Physical Chemistry C	Abbreviated Journal	J Phys Chem C
	Volume	124	Issue	34	Pages	18401-18415
	Keywords	A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Plasma technology is gaining increasing interest for CO2 conversion. The gas temperature in (and after) the plasma reactor largely aﬀects the performance. Therefore, we examine the eﬀect of cooling/quenching, during and after the plasma, on the CO2 conversion and energy eﬃciency, for typical “warm” plasmas, by means of chemical kinetics modeling. For plasmas at low speciﬁc energy input (SEI ∼ 0.5 eV/molecule), it is best to quench at the plasma end, while for high-SEI plasmas (SEI ∼ 4 eV/molecule), quenching at maximum conversion is better. For low-SEI plasmas, quenching can even increase the conversion beyond the dissociation in the plasma, known as superideal quenching. To better understand the eﬀects of quenching at diﬀerent plasma conditions, we study the dissociation and recombination rates, as well as the vibrational distribution functions (VDFs) of CO2, CO, and O2. When a high vibrational−translational (VT) nonequilibrium exists at the moment of quenching, the dissociation and recombination reaction rates both increase. Depending on the conversion degree at the moment of quenching, this can lead to a net increase or decrease of CO2 conversion. In general, however, and certainly for equilibrium plasmas at high temperature, quenching after the plasma helps prevent recombination reactions and clearly enhances the ﬁnal CO2 conversion. We also investigate the eﬀect of diﬀerent quenching cooling rates on the CO2 conversion and energy eﬃciency. Finally, we compare plasma-based conversion to purely thermal conversion. For warm plasmas with typical temperatures of 3000−4000 K, the conversion is roughly thermal.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000566481000003	Publication Date	2020-08-27
	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, G.0383.16N ; H2020 European Research Council, 810182 ; This research was supported by the FWO project (grant no. G.0383.16N) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (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: 3.7; 2020 IF: 4.536
	Call Number	PLASMANT @ plasmant @c:irua:172052			Serial	6407
Permanent link to this record



	Author	Van Alphen, S.; Vermeiren, V.; Butterworth, T.; van den Bekerom, D.C.M.; van Rooij, G.J.; Bogaerts, A.
	Title	Power Pulsing To Maximize Vibrational Excitation Efficiency in N₂Microwave Plasma: A Combined Experimental and Computational Study			Type	A1 Journal article
	Year	2020	Publication	Journal Of Physical Chemistry C	Abbreviated Journal	J Phys Chem C
	Volume	124	Issue	3	Pages	1765-1779
	Keywords	A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Plasma is gaining increasing interest for N2 ﬁxation, being a ﬂexible, electricity-driven alternative for the current conventional fossil fuel-based N2 ﬁxation processes. As the vibrational-induced dissociation of N2 is found to be an energy-eﬃcient pathway to acquire atomic N for the ﬁxation processes, plasmas that are in vibrational nonequilibrium seem promising for this application. However, an important challenge in using nonequilibrium plasmas lies in preventing vibrational−translational (VT) relaxation processes, in which vibrational energy crucial for N2 dissociation is lost to gas heating. We present here both experimental and modeling results for the vibrational and gas temperature in a microsecond-pulsed microwave (MW) N2 plasma, showing how power pulsing can suppress this unfavorable VT relaxation and achieve a maximal vibrational nonequilibrium. By means of our kinetic model, we demonstrate that pulsed plasmas take advantage of the long time scale on which VT processes occur, yielding a very pronounced nonequilibrium over the whole N2 vibrational ladder. Additionally, the eﬀect of pulse parameters like the pulse frequency and pulse width are investigated, demonstrating that the advantage of pulsing to inhibit VT relaxation diminishes for high pulse frequencies (around 7000 kHz) and long power pulses (above 400 μs). Nevertheless, all regimes studied here demonstrate a clear vibrational nonequilibrium while only requiring a limited power-on time, and thus, we may conclude that a pulsed plasma seems very interesting for energyeﬃcient vibrational excitation.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000509438600001	Publication Date	2020-01-23
	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
	Notes	Fonds Wetenschappelijk Onderzoek, 30505023 GoF9618n ; 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.			Approved	Most recent IF: 3.7; 2020 IF: 4.536
	Call Number	PLASMANT @ plasmant @c:irua:165586			Serial	5443
Permanent link to this record



	Author	Vermeiren, V.
	Title	Chemical kinetics modeling of non-equilibrium and thermal effects in vibrationally active CO2 plasmas			Type	Doctoral thesis
	Year	2020	Publication		Abbreviated Journal
	Volume		Issue		Pages	207 p.
	Keywords	Doctoral thesis; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos		Publication Date
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Additional Links	UA library record
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ admin @ c:irua:173385			Serial	6468
Permanent link to this record



	Author	Vermeiren, V.; Bogaerts, A.
	Title	Improving the Energy Efficiency of CO₂Conversion in Nonequilibrium Plasmas through Pulsing			Type	A1 Journal article
	Year	2019	Publication	The journal of physical chemistry: C : nanomaterials and interfaces	Abbreviated Journal	J Phys Chem C
	Volume	123	Issue	29	Pages	17650-17665
	Keywords	A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Nonequilibrium plasmas oﬀer a pathway for energy-eﬃcient CO2 conversion through vibrationally induced dissociation. However, the eﬃciency of this pathway is limited by a rise in gas temperature, which increases vibrational−translational (VT) relaxation and quenches the vibrational levels. Therefore, we investigate here the eﬀect of plasma pulsing on the VT nonequilibrium and on the CO2 conversion by means of a zerodimensional chemical kinetics model, with self-consistent gas temperature calculation. Speciﬁcally, we show that higher energy eﬃciencies can be reached by correctly tuning the plasma pulse and interpulse times. The ideal plasma pulse time corresponds to the time needed to reach the highest vibrational temperature. In addition, the highest energy eﬃciencies are obtained with long interpulse times, that is, ≥0.1 s, in which the gas temperature can entirely drop to room temperature. Furthermore, additional cooling of the reactor walls can give higher energy eﬃciencies at shorter interpulse times of 1 ms. Finally, our model shows that plasma pulsing can signiﬁcantly improve the energy eﬃciency at low reduced electric ﬁelds (50 and 100 Td, typical for microwave and gliding arc plasmas) and intermediate ionization degrees (5 × 10−7 and 10−6).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000477785000003	Publication Date	2019-07-25
	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	4.536	Times cited	1	Open Access
	Notes	Fonds Wetenschappelijk Onderzoek, G.0383.16N ; This research was supported by the FWO project (grant G.0383.16N). 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. We also like to thank N. Britun (ChIPS) for the interesting discussions.			Approved	Most recent IF: 4.536
	Call Number	PLASMANT @ plasmant @c:irua:161621			Serial	5289
Permanent link to this record



	Author	Vermeiren, V.; Bogaerts, A.
	Title	Supersonic Microwave Plasma: Potential and Limitations for Energy-Efficient CO₂Conversion			Type	A1 Journal Article
	Year	2018	Publication	Journal Of Physical Chemistry C	Abbreviated Journal	J Phys Chem C
	Volume	122	Issue	45	Pages	25869-25881
	Keywords	A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
	Abstract	Supersonic flows provide a high thermodynamic nonequilibrium, which is crucial for energy-efficient conversion of CO 2 in microwave plasmas and are therefore of great interest. However, the effect of the flow on the chemical reactions is poorly understood. In this work, we present a combined flow and plasma chemical kinetics model of a microwave CO 2 plasma in a Laval nozzle setup. The effects of the flow field on the different dissociation and recombination mechanisms, the vibrational distribution, and the vibrational transfer mechanism are discussed. In addition, the effect of experimental parameters, like position of power deposition, outlet pressure, and specific energy input, on the CO 2 conversion and energy efficiency is examined. The short residence time of the gas in the plasma region, the shockwave, and the maximum critical heat, and thus power, that can be added to the flow to avoid thermal choking are the main obstacles to reaching high energy efficiencies.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000451101400016	Publication Date	2018-11-15
	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	4.536	Times cited	5	Open Access	Not_Open_Access
	Notes	Fonds Wetenschappelijk Onderzoek, G.0383.16N ;			Approved	Most recent IF: 4.536
	Call Number	PLASMANT @ plasmant @c:irua:155412			Serial	5070
Permanent link to this record



	Author	Belov, I.; Vermeiren, V.; Paulussen, S.; Bogaerts, A.
	Title	Carbon dioxide dissociation in a microwave plasma reactor operating in a wide pressure range and different gas inlet configurations			Type	A1 Journal article
	Year	2018	Publication	Journal of CO2 utilization	Abbreviated Journal	J Co2 Util
	Volume	24	Issue		Pages	386-397
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Microwave (MW) plasmas represent a promising solution for efficient CO2 dissociation. MW discharges are also very versatile and can be sustained at various pressure and gas flow regimes. To identify the most favorable conditions for the further scale-up of the CO2 decomposition reaction, a MW plasma reactor operating in pure CO2 in a wide pressure range (200 mbar–1 bar) is studied. Three different gas flow configurations are explored: a direct, reverse and a vortex regime. The CO2 conversion and energy efficiency drop almost linearly with increasing pressure, regardless of the gas flow regime. The results obtained in the direct flow configuration underline the importance of post-discharge cooling, as the exhaust of the MW plasma reactor in this regime expanded into the vacuum chamber without additional quenching. As a result, this system yields exhaust temperatures of up to 1000 K, which explains the lowest conversion (∼3.5% at 200 mbar and 2% at 1 bar). A post-discharge cooling step is introduced for the reverse gas inlet regime and allows the highest conversion to be achieved (∼38% at 200 mbar and 6.2% at 1 bar, with energy efficiencies of 23% and 3.7%). Finally, a tangential gas inlet is utilized in the vortex configuration to generate a swirl flow pattern. This results in the generation of a stable discharge in a broader range of CO2 flows (15–30 SLM) and the highest energy efficiencies obtained in this study (∼25% at 300 mbar and ∼13% at 1 bar, at conversions of 21% and 12%). The experimental results are complemented with computational fluid dynamics simulations and with the analysis of the latest literature to identify the further research directions.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000428234500045	Publication Date	2018-03-15
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2212-9820	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.292	Times cited	8	Open Access	Not_Open_Access: Available from 16.03.2020
	Notes	The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7-PEOPLE-2013- ITN) under Grant Agreement№606889 (R			Approved	Most recent IF: 4.292
	Call Number	PLASMANT @ plasmant @c:irua:150874			Serial	4955
Permanent link to this record