NANOlab Center of Excellence literature database -- Query Results

“Sustainable gas conversion by gliding arc plasmas: a new modelling approach for reactor design improvement”. Van Alphen S, Jardali F, Creel J, Trenchev G, Snyders R, Bogaerts A, Sustainable energy &, fuels 5, 1786 (2021). http://doi.org/10.1039/D0SE01782E Abstract: Research in plasma reactor designs is developing rapidly as plasma technology is gaining increasing interest for sustainable gas conversion applications, like the conversion of greenhouse gases into value-added chemicals and renewable fuels, and fixation of N<sub>2</sub>from air into precursors of mineral fertilizer. As plasma is generated by electric power and can easily be switched on/off, these applications allows for efficient conversion and energy storage of intermittent renewable electricity. In this paper, we present a new comprehensive modelling approach for the design and development of gliding arc plasma reactors, which reveals the fluid dynamics, the arc behaviour and the plasma chemistry by solving a unique combination of five complementary models. This results in a complete description of the plasma process, which allows one to efficiently evaluate the performance of a reactor and indicate possible design improvements before actually building it. We demonstrate the capabilities of this method for an experimentally validated study of plasma-based NO<sub>x</sub>formation in a rotating gliding arc reactor, which is gaining increasing interest as a flexible, electricity-driven alternative for the Haber–Bosch process. The model demonstrates the importance of the vortex flow and the presence of a recirculation zone in the reactor, as well as the formation of hot spots in the plasma near the cathode pin and the anode wall that are responsible for most of the NO<sub>x</sub>formation. The model also reveals the underlying plasma chemistry and the vibrational non-equilibrium that exists due to the fast cooling during each arc rotation. Good agreement with experimental measurements on the studied reactor design proves the predictive capabilities of our modelling approach. Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) DOI: 10.1039/D0SE01782E Additional Links: UA library record; WoS full record; WoS citing articles show.php?record=6745
“Suppressing the formation of NO_xand N₂O in CO₂/N₂dielectric barrier discharge plasma by adding CH₄: scavenger chemistry at work”. Snoeckx R, Van Wesenbeeck K, Lenaerts S, Cha MS, Bogaerts A, Sustainable Energy &, Fuels 3, 1388 (2019). http://doi.org/10.1039/C8SE00584B Abstract: The need for carbon negative technologies led to the development of a wide array of novel CO<sub>2</sub>conversion techniques. Most of them either rely on high temperatures or generate highly reactive O species, which can lead to the undesirable formation of NO<sub>x</sub>and N<sub>2</sub>O when the CO<sub>2</sub>feeds contain N<sub>2</sub>. Here, we show that, for plasma-based CO<sub>2</sub>conversion, adding a hydrogen source, as a chemical oxygen scavenger, can suppress their formation,<italic>in situ</italic>. This allows the use of low-cost N<sub>2</sub>containing (industrial and direct air capture) feeds, rather than expensive purified CO<sub>2</sub>. To demonstrate this, we add CH<sub>4</sub>to a dielectric barrier discharge plasma used for converting impure CO<sub>2</sub>. We find that when adding a stoichiometric amount of CH<sub>4</sub>, 82% less NO<sub>2</sub>and 51% less NO are formed. An even higher reduction (96 and 63%) can be obtained when doubling this amount. However, in that case the excess radicals promote the formation of by-products, such as HCN, NH<sub>3</sub>and CH<sub>3</sub>OH. Thus, we believe that by using an appropriate amount of chemical scavengers, we can use impure CO<sub>2</sub>feeds, which would bring us closer to ‘real world’ conditions and implementation. Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Sustainable Energy, Air and Water Technology (DuEL) DOI: 10.1039/C8SE00584B Additional Links: UA library record; WoS full record; WoS citing articles show.php?record=5188

Abstract: Research in plasma reactor designs is developing rapidly as plasma technology is gaining increasing interest for sustainable gas conversion applications, like the conversion of greenhouse gases into value-added chemicals and renewable fuels, and fixation of N2from air into precursors of mineral fertilizer. As plasma is generated by electric power and can easily be switched on/off, these applications allows for efficient conversion and energy storage of intermittent renewable electricity. In this paper, we present a new comprehensive modelling approach for the design and development of gliding arc plasma reactors, which reveals the fluid dynamics, the arc behaviour and the plasma chemistry by solving a unique combination of five complementary models. This results in a complete description of the plasma process, which allows one to efficiently evaluate the performance of a reactor and indicate possible design improvements before actually building it. We demonstrate the capabilities of this method for an experimentally validated study of plasma-based NOxformation in a rotating gliding arc reactor, which is gaining increasing interest as a flexible, electricity-driven alternative for the Haber–Bosch process. The model demonstrates the importance of the vortex flow and the presence of a recirculation zone in the reactor, as well as the formation of hot spots in the plasma near the cathode pin and the anode wall that are responsible for most of the NOxformation. The model also reveals the underlying plasma chemistry and the vibrational non-equilibrium that exists due to the fast cooling during each arc rotation. Good agreement with experimental measurements on the studied reactor design proves the predictive capabilities of our modelling approach.

Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)

DOI: 10.1039/D0SE01782E

Additional Links: UA library record; WoS full record; WoS citing articles

show.php?record=6745

Abstract: The need for carbon negative technologies led to the development of a wide array of novel CO2conversion techniques. Most of them either rely on high temperatures or generate highly reactive O species, which can lead to the undesirable formation of NOxand N2O when the CO2feeds contain N2. Here, we show that, for plasma-based CO2conversion, adding a hydrogen source, as a chemical oxygen scavenger, can suppress their formation,<italic>in situ</italic>. This allows the use of low-cost N2containing (industrial and direct air capture) feeds, rather than expensive purified CO2. To demonstrate this, we add CH4to a dielectric barrier discharge plasma used for converting impure CO2. We find that when adding a stoichiometric amount of CH4, 82% less NO2and 51% less NO are formed. An even higher reduction (96 and 63%) can be obtained when doubling this amount. However, in that case the excess radicals promote the formation of by-products, such as HCN, NH3and CH3OH. Thus, we believe that by using an appropriate amount of chemical scavengers, we can use impure CO2feeds, which would bring us closer to ‘real world’ conditions and implementation.