Nonthermal plasma#Aerospace

In the context of food processing, a nonthermal plasma (NTP) or cold plasma is specifically an antimicrobial treatment being investigated for application to fruits, vegetables and meat products with fragile surfaces.{{cite web|url=http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=409114 |title=Decontamination of Fresh Production with Cold Plasma |accessdate=2006-07-28 |website=U.S. Department of Agriculture}}

These foods are either not adequately sanitized or are otherwise unsuitable for treatment with chemicals, heat or other conventional food processing tools. While the applications of nonthermal plasma were initially focused on microbiological disinfection,Laroussi, M. (1996). “Sterilization of Contaminated Matter by an Atmospheric Pressure Plasma”, IEEE Trans. Plasma Sci. 34, 1188 – 1191. newer applications such as enzyme inactivation, biomolecule oxidation, protein modification, prodrug activation, and pesticide dissipation are being actively researched.

{{cite journal|title=d-Glucose Oxidation by Cold Atmospheric Plasma-Induced Reactive Species |journal=ACS Omega|year=2022 |doi=10.1021/acsomega.2c02965 |last1=Ahmadi |first1=Mohsen |last2=Nasri |first2=Zahra |last3=von Woedtke |first3=Thomas |last4=Wende |first4=Kristian |volume=7 |issue=36 |pages=31983–31998 |pmid=36119990 |pmc=9475618 }}{{cite journal|title=Singlet-Oxygen-Induced Phospholipase A2 Inhibition: A Major Role for Interfacial Tryptophan Dioxidation |journal=Chemistry – A European Journal|year=2021 |doi=10.1002/chem.202102306 |last1=Nasri |first1=Zahra |last2=Memari |first2=Seyedali |last3=Wenske |first3=Sebastian |last4=Clemen |first4=Ramona |last5=Martens |first5=Ulrike |last6=Delcea |first6=Mihaela |last7=Bekeschus |first7=Sander |last8=Weltmann |first8=Klaus-Dieter |last9=Woedtke |first9=Thomas |last10=Wende |first10=Kristian |volume=27 |issue=59 |pages=14702–14710 |pmid=34375468 |pmc=8596696 }}{{cite book|chapter-url=https://ieeexplore.ieee.org/document/9813129 |accessdate=2022-07-01 |year=2022 |doi=10.1109/ICOPS45751.2022.9813129 |last1=Wende |first1=K. |last2=Nasri |first2=Z. |last3=Striesow |first3=J. |last4=Ravandeh |first4=M. |last5=Weltmann |first5=K.-D. |last6=Bekeschus |first6=S. |last7=Woedtke |first7=T. von |title=2022 IEEE International Conference on Plasma Science (ICOPS) |chapter=Is Biomolecule Oxidation by Plasma-Derived Reactive Species Restricted to the Gas-Liquid Interphase? |pages=1–2 |isbn=978-1-6654-7925-7 |s2cid=250318321 }}

{{cite journal|title=Flucytosine-based prodrug activation by cold physical plasma |journal= Archiv der Pharmazie|year=2022 |doi=10.1002/ardp.202200061 |last1=Ahmadi |first1=Mohsen |last2=Potlitz |first2=Felix |last3=Link |first3=Andreas |last4=von Woedtke |first4=Thomas |last5=Nasri |first5=Zahra |last6=Wende |first6=Kristian |volume=355 |issue=9 |pages=e2200061 |pmid=35621706 |s2cid=249095233 |doi-access=free }} Nonthermal plasma also sees increasing use in the sterilization of teeth{{cite web|url=http://www.rdmag.com/ShowPR.aspx?PUBCODE=014&ACCT=1400000101&ISSUE=0906&RELTYPE=PR&PRODCODE=00000000&PRODLETT=GD&CommonCount=0|title=Plasma rips away tenacious tooth bacteria|last=|first=|date=2009-06-11|website=|accessdate=2009-06-20}}{{cite web|url=http://uscnews.usc.edu/science_technology/cool_plasma_pack_heat_against_biofilms.html|title=Cool plasma packs heat against biofilm|author=Beth Dunham|date=June 5, 2009|accessdate=2009-06-20|archive-url=https://web.archive.org/web/20090618024004/http://uscnews.usc.edu/science_technology/cool_plasma_pack_heat_against_biofilms.html|archive-date=June 18, 2009|url-status=dead}} and hands,{{cite news|url=https://www.nytimes.com/2010/02/14/business/14novel.html?_r=1&ref=technology|title=Hospital-Clean Hands, Without All the Scrubbing|last=Eisenberg|first=Anne|date=2010-02-13|work=The New York Times|accessdate=2011-02-28}} in hand dryers{{cite web|url=https://www.bloomberg.com/research/markets/news/article.asp?docKey=600-201503270628M2______EUPR_____7117000004028e93_3600-1|title=American Dryer UK Set To Transform Hand Hygiene With Pioneering 'Germ Destroying'|date=2015-03-27|website=Bloomberg|archive-url=https://web.archive.org/web/20150403015257/http://www.bloomberg.com/research/markets/news/article.asp?docKey=600-201503270628M2______EUPR_____7117000004028e93_3600-1|archive-date=2015-04-03|url-status=dead}} as well as in self-decontaminating filters.{{cite conference|last=Kuznetsov|first=I.A.|author2=Saveliev, A.V.|author3=Rasipuram, S.|author4=Kuznetsov, A.V.|author5=Brown, A.|author6=Jasper, W.|year=2012|title=Development of Active Porous Medium Filters Based on Plasma Textiles|conference=Porous Media and Its Applications in Science, Engineering and Industry, AIP Conf. Proc. 1453|volume=1453|issue=1|pages=265–270|doi=10.1063/1.4711186|series=AIP Conference Proceedings|bibcode=2012AIPC.1453..265K}}

The term cold plasma has been recently used as a convenient descriptor to distinguish the one-atmosphere, near room temperature plasma discharges from other plasmas, operating at hundreds or thousands of degrees above ambient (see {{format link|Plasma (physics)#Temperature}}. Within the context of food processing the term "cold" can potentially engender misleading images of refrigeration requirements as a part of the plasma treatment. However, in practice this confusion has not been an issue. "Cold plasmas" may also loosely refer to weakly ionized gases (degree of ionization < 0.01%).

The nomenclature for nonthermal plasma found in the scientific literature is varied. In some cases, the plasma is referred to by the specific technology used to generate it ("gliding arc", "plasma pencil", "plasma needle", "plasma jet", "dielectric barrier discharge", "piezoelectric direct discharge plasma", etc.), while other names are more generally descriptive, based on the characteristics of the plasma generated ("one atmosphere uniform glow discharge plasma", "atmospheric plasma", "ambient pressure nonthermal discharges", "non-equilibrium atmospheric pressure plasmas", etc.). The two features which distinguish NTP from other mature, industrially applied plasma technologies, is that they are 1) nonthermal and 2) operate at or near atmospheric pressure.

{{main|Plasma medicine}}

An emerging field adds the capabilities of nonthermal plasma to dentistry and medicine. Cold plasma is used to treat chronic wounds.{{Cite journal |last1=Abu Rached |first1=Nessr |last2=Kley |first2=Susanne |last3=Storck |first3=Martin |last4=Meyer |first4=Thomas |last5=Stücker |first5=Markus |date=January 2023 |title=Cold Plasma Therapy in Chronic Wounds—A Multicenter, Randomized Controlled Clinical Trial (Plasma on Chronic Wounds for Epidermal Regeneration Study): Preliminary Results |journal=Journal of Clinical Medicine |language=en |volume=12 |issue=15 |pages=5121 |doi=10.3390/jcm12155121 |issn=2077-0383 |pmc=10419810 |pmid=37568525 |doi-access=free }}

{{main|Magnetohydrodynamic generator}}

{{see also|Electrothermal instability}}

Magnetohydrodynamic power generation, a direct energy conversion method from a hot gas in motion within a magnetic field was developed in the 1960s and 1970s with pulsed MHD generators known as shock tubes, using non-equilibrium plasmas seeded with alkali metal vapors (like caesium, to increase the limited electrical conductivity of gases) heated at a limited temperature of 2000 to 4000 kelvins (to protect walls from thermal erosion) but where electrons were heated at more than 10,000 kelvins.{{cite journal

|last1=Kerrebrock

|first1=Jack L.

|last2=Hoffman

|first2=Myron A.

|title=Non-Equilibrium Ionization Due to Electron Heating. Theory and Experiments

|date=June 1964

|journal=AIAA Journal

|volume=2

|issue=6

|pages=1072–1087

|doi=10.2514/3.2497

|url=http://ayuba.fr/pdf/kerrebrock1964.pdf

|bibcode=1964AIAAJ...2.1080H

|access-date=2018-04-10

|archive-date=2019-08-19

|archive-url=https://web.archive.org/web/20190819083451/http://ayuba.fr/pdf/kerrebrock1964.pdf

|url-status=dead

}}{{cite journal

|last1=Sherman

|first1=A.

|title=MHD Channel Flow with Non-Equilibrium lonization

|date=September 1966

|journal=The Physics of Fluids

|volume=9

|issue=9

|pages=1782–1787

|doi=10.1063/1.1761933

|url=http://ayuba.fr/pdf/sherman1966.pdf

|bibcode=1966PhFl....9.1782S

|access-date=2018-04-10

|archive-date=2018-04-12

|archive-url=https://web.archive.org/web/20180412082322/http://ayuba.fr/pdf/sherman1966.pdf

|url-status=dead

}}{{cite journal

|last1=Argyropoulos |first1=G. S.

|last2=Demetriades |first2=S. T.

|last3=Kentig |first3=A. P.

|title=Current Distribution in Non-Equilibrium J×B Devices

|date=1967

|journal=Journal of Applied Physics

|volume=38

|issue=13

|pages=5233–5239

|doi=10.1063/1.1709306

|url=http://ayuba.fr/pdf/argyropoulos1967

|format=PDF

|bibcode=1967JAP....38.5233A}}{{cite journal

|last1=Zauderer |first1=B.

|last2=Tate |first2= E.

|title=Electrical characteristics of a linear, nonequilibrium, MHD generator

|date=September 1968

|journal=AIAA Journal

|volume=6

|issue=9

|pages=1683–1694

|doi=10.2514/3.4846

|url=http://ayuba.fr/pdf/zauderer1968.pdf

|bibcode=1968AIAAJ...6.1685T

}}

A particular and unusual case of "inverse" nonthermal plasma is the very high temperature plasma produced by the Z machine, where ions are much hotter than electrons.{{cite journal

|last1=Haines |first1=M. G.

|last2=LePell |first2=P. D.

|last3=Coverdale |first3=C. A.|author3-link=Christine Coverdale

|last4=Jones |first4=B.

|last5=Deeney |first5=C.

|last6=Apruzese |first6=J. P.

|title=Ion Viscous Heating in a Magnetohydrodynamically Unstable Pinch at Over 2 × 10{{sup|9}} Kelvin

|date=23 February 2006

|journal=Physical Review Letters

|volume=96

|issue=7

|pages=075003

|url=http://ayuba.fr/pdf/haines2006.pdf

|doi=10.1103/PhysRevLett.96.075003

|pmid=16606100

|bibcode=2006PhRvL..96g5003H}}{{cite web|url=http://ayuba.fr/pdf/comments_on_haines_paper.pdf |last1=Petit |first1=J.-P. |title=The Z Machine: Over two billion degrees! Malcolm Haines' paper |accessdate=2018-04-07}}

{{main|Magnetohydrodynamic converter}}

{{see also|Paschen's law}}

Aerodynamic active flow control solutions involving technological nonthermal weakly ionized plasmas for subsonic, supersonic and hypersonic flight are being studied, as plasma actuators in the field of electrohydrodynamics, and as magnetohydrodynamic converters when magnetic fields are also involved.{{cite book |editor1-last=Molokov |editor1-first=Sergei S. |editor2-last=Moreau |editor2-first=R. |editor3-last= Moffatt |editor3-first=H. Keith |title=Magnetohydrodynamics: Historical Evolution and Trends |last1=Weier |first1=Tom |last2=Shatrov |first2=Victor |last3=Gerbeth |first3=Gunter |chapter=Flow Control and Propulsion in Poor Conductors |pages=295–312|publisher=Springer Science+Business Media |date=2007 |isbn=978-1-4020-4832-6 |doi=10.1007/978-1-4020-4833-3}}

Studies conducted in wind tunnels involve most of the time low atmospheric pressure similar to an altitude of 20–50 km, typical of hypersonic flight, where the electrical conductivity of air is higher, hence non-thermal weakly ionized plasmas can be easily produced with a fewer energy expense.{{citation needed|date=August 2023}}

Atmospheric pressure non-thermal plasma can be used to promote chemical reactions. Collisions between hot temperature electrons and cold gas molecules can lead to dissociation reactions and the subsequent formation of radicals. This kind of discharge exhibits reacting properties that are usually seen in high temperature discharge systems.{{cite journal|last1=Whitehead|first1=J Christopher|title=Plasma–catalysis: the known knowns, the known unknowns and the unknown unknowns|journal=Journal of Physics D: Applied Physics|date=22 June 2016|volume=49|issue=24|pages=243001|doi=10.1088/0022-3727/49/24/243001|bibcode=2016JPhD...49x3001W|s2cid=101887286 |url=https://www.research.manchester.ac.uk/portal/en/publications/plasmacatalysis(04b2ec5b-0229-4ba9-8b12-ac07c038905c).html }} Non-thermal plasma is also used in conjunction with a catalyst to further enhance the chemical conversion of reactants or to alter the products chemical composition.

Among the different application fields, there are ozone production{{cite journal|last1=Eliasson|first1=B|last2=Hirth|first2=M|last3=Kogelschatz|first3=U|title=Ozone synthesis from oxygen in dielectric barrier discharges|journal=Journal of Physics D: Applied Physics|date=14 November 1987|volume=20|issue=11|pages=1421–1437|doi=10.1088/0022-3727/20/11/010|bibcode=1987JPhD...20.1421E |s2cid=250811914}} at a commercial level; pollution abatement, both solid (PM, VOC) and gaseous (SOx, NOx);{{cite journal|last1=Chang|first1=Jen-Shih|title=Recent development of plasma pollution control technology: a critical review|journal=Science and Technology of Advanced Materials|date=December 2001|volume=2|issue=3–4|pages=571–576|doi=10.1016/S1468-6996(01)00139-5|bibcode=2001STAdM...2..571C |doi-access=free}} CO₂ conversion{{cite journal|last1=Ashford|first1=Bryony|last2=Tu|first2=Xin|title=Non-thermal plasma technology for the conversion of CO 2|journal=Current Opinion in Green and Sustainable Chemistry|date=February 2017|volume=3|pages=45–49|doi=10.1016/j.cogsc.2016.12.001}} in fuels (methanol, syngas) or value added chemicals; nitrogen fixation; methanol synthesis; liquid fuels synthesis from lighter hydrocarbons (e.g. methane),{{cite journal|last1=De Bie|first1=Christophe|last2=Verheyde|first2=Bert|last3=Martens|first3=Tom|last4=van Dijk|first4=Jan|last5=Paulussen|first5=Sabine|last6=Bogaerts|first6=Annemie|author6-link= Annemie Bogaerts |title=Fluid Modeling of the Conversion of Methane into Higher Hydrocarbons in an Atmospheric Pressure Dielectric Barrier Discharge|journal=Plasma Processes and Polymers|date=23 November 2011|volume=8|issue=11|pages=1033–1058|doi=10.1002/ppap.201100027}} hydrogen production via hydrocarbons reforming{{cite journal|last1=CHEN|first1=H|last2=LEE|first2=H|last3=CHEN|first3=S|last4=CHAO|first4=Y|last5=CHANG|first5=M|title=Review of plasma catalysis on hydrocarbon reforming for hydrogen production—Interaction, integration, and prospects|journal=Applied Catalysis B: Environmental|date=17 December 2008|volume=85|issue=1–2|pages=1–9|doi=10.1016/j.apcatb.2008.06.021}}

The coupling between the two different mechanisms can be done in two different ways: two-stage configuration, also called post-plasma catalysis (PPC) and one-stage configuration, also called in-plasma catalysis (IPC) or plasma enhanced catalysis (PEC).

In the first case the catalytic reactor is placed after the plasma chamber. This means that only the long-lived species can reach the catalyst surface and react, while short-lived radicals, ions and excited species decay in the first part of the reactor. As an example, the oxygen ground state atom O(3P) has a lifetime of about 14 μs{{cite journal |last1=Holzer |first1=F |title=Combination of non-thermal plasma and heterogeneous catalysis for oxidation of volatile organic compounds Part 1. Accessibility of the intra-particle volume |journal=Applied Catalysis B: Environmental |date=September 2002 |volume=38 |issue=3 |pages=163–181 |doi=10.1016/S0926-3373(02)00040-1}} in a dry air atmospheric pressure plasma. This means that only a small region of the catalyst is in contact with active radicals. In a such two-stage set-up, the main role of the plasma is to alter the gas composition fed to the catalytic reactor.{{cite journal |last1=Neyts |first1=E C |last2=Bogaerts |first2=A|author2-link= Annemie Bogaerts |title=Understanding plasma catalysis through modelling and simulation—a review |journal=Journal of Physics D: Applied Physics |date=4 June 2014 |volume=47 |issue=22 |pages=224010 |doi=10.1088/0022-3727/47/22/224010|bibcode=2014JPhD...47v4010N |s2cid=120159417 }} In a PEC system, synergistic effects are greater since short-lived excited species are formed near the catalyst surface.{{cite journal |last1=Harling |first1=Alice M. |last2=Glover |first2=David J. |last3=Whitehead |first3=J. Christopher |last4=Zhang |first4=Kui |title=The role of ozone in the plasma-catalytic destruction of environmental pollutants |journal=Applied Catalysis B: Environmental |date=July 2009 |volume=90 |issue=1–2 |pages=157–161 |doi=10.1016/j.apcatb.2009.03.005}} The way the catalyst is inserted in the PEC reactor influence the overall performance. It can be placed inside the reactor in different ways: in powder form (packed bed), deposited on foams, deposited on structured material (honeycomb), and coating of the reactor walls

Packed bed plasma-catalytic reactor are commonly used for fundamental studies and a scale-up to industrial applications is difficult since the pressure drop increase with the flow rate.

In a PEC system, the way the catalyst is positioned in relation to the plasma can affect the process in different ways. The catalyst can positively influence the plasma and vice versa resulting in an output that cannot be obtained using each process individually. The synergy that is established is ascribed to different cross effects.

{{cite journal|last1=Neyts|first1=E C|last2=Bogaerts|first2=A|author2-link= Annemie Bogaerts |title=Understanding plasma catalysis through modelling and simulation—a review|journal=Journal of Physics D: Applied Physics|date=4 June 2014|volume=47|issue=22|pages=224010|doi=10.1088/0022-3727/47/22/224010|bibcode=2014JPhD...47v4010N |s2cid=120159417 }}

{{cite journal|last1=Chen|first1=Hsin Liang|last2=Lee|first2=How Ming|last3=Chen|first3=Shiaw Huei|last4=Chang|first4=Moo Been|last5=Yu|first5=Sheng Jen|last6=Li|first6=Shou Nan|title=Removal of Volatile Organic Compounds by Single-Stage and Two-Stage Plasma Catalysis Systems: A Review of the Performance Enhancement Mechanisms, Current Status, and Suitable Applications|journal=Environmental Science & Technology|date=April 2009|volume=43|issue=7|pages=2216–2227|doi=10.1021/es802679b|pmid=19452866|bibcode=2009EnST...43.2216C }}

{{cite journal|last1=Van Durme|first1=Jim|last2=Dewulf|first2=Jo|last3=Leys|first3=Christophe|last4=Van Langenhove|first4=Herman|title=Combining non-thermal plasma with heterogeneous catalysis in waste gas treatment: A review|journal=Applied Catalysis B: Environmental|date=February 2008|volume=78|issue=3–4|pages=324–333|doi=10.1016/j.apcatb.2007.09.035|hdl=1854/LU-419124 |url=https://biblio.ugent.be/publication/419124|hdl-access=free}}

{{cite journal|last1=Vandenbroucke|first1=Arne M.|last2=Morent|first2=Rino|last3=De Geyter|first3=Nathalie|last4=Leys|first4=Christophe|title=Non-thermal plasmas for non-catalytic and catalytic VOC abatement|journal=Journal of Hazardous Materials|date=November 2011|volume=195|pages=30–54|doi=10.1016/j.jhazmat.2011.08.060|pmid=21924828 }}

• Plasma effects on catalyst:
• Change in the physiochemical properties. Plasma change the adsorption/desorption equilibrium on the catalyst surface leading to higher adsorption capabilities. An interpretation to this phenomenon is not yet clear.{{cite journal|last1=Blin-Simiand|first1=Nicole|last2=Tardiveau|first2=Pierre|last3=Risacher|first3=Aurore|last4=Jorand|first4=François|last5=Pasquiers|first5=Stéphane|title=Removal of 2-Heptanone by Dielectric Barrier Discharges – The Effect of a Catalyst Support|journal=Plasma Processes and Polymers|date=31 March 2005|volume=2|issue=3|pages=256–262|doi=10.1002/ppap.200400088}}
• Higher catalyst surface area. A catalyst exposed to a discharge can give rise to the formation of nanoparticles.{{cite journal|last1=Hong|first1=Jingping|last2=Chu|first2=Wei|last3=Chernavskii|first3=Petr A.|last4=Khodakov|first4=Andrei Y.|title=Cobalt species and cobalt-support interaction in glow discharge plasma-assisted Fischer–Tropsch catalysts|journal=Journal of Catalysis|date=7 July 2010|volume=273|issue=1|pages=9–17|doi=10.1016/j.jcat.2010.04.015}} The higher surface/volume ratio leads to better catalyst performances.
• Higher adsorption probability.
• Change in the catalyst oxidation state. Some metallic catalyst (e.g. Ni, Fe) are more active in their metallic form. The presence of a plasma discharge can induce a reduction of the catalyst metal oxides, improving the catalytic activity.
• Reduced coke formation. When dealing with hydrocarbons, coke formation leads to a progressive deactivation of the catalyst.{{Cite book|last1=Beuther|first1=H.|last2=Larson|first2=O.A.|last3=Perrotta|first3=A.J.|title=The Mechanism of Coke Formation on Catalysts|journal=Catalyst Deactivation|volume=6|date=1980|pages=271–282|doi=10.1016/s0167-2991(08)65236-2|series=Studies in Surface Science and Catalysis|isbn=9780444419200 }} The reduced coke formation in presence of plasma reduces the poisoning/deactivation rate and thus extending the life of a catalyst.
• Presence of new gas phase species. In a plasma discharge a wide range of new species is produced allowing the catalyst to be exposed to them. Ions, vibrationally and rotationally excited species do not affect the catalyst since they lose charge and the additional energy they possess when they reach a solid surface. Radicals, instead, show high sticking coefficients for chemisorption, increasing the catalytic activity.

• Catalyst effects on plasma:
• Local electric field enhancement. This aspect is mainly related to a packed-bed PEC configuration. The presence of a packing material inside an electric field generates local field enhancements due to the presence of asperities, solid material surface inhomogeneities, presence of pores and other physical aspects. This phenomenon is related to surface charge accumulation on the packing material surface and it is present even if a packed-bed is used without a catalyst. Despite this is a physical aspect, it also affects the chemistry since it alters the electron energy distribution in proximity of the asperities.
• Discharges formation inside pores. This aspect is strictly related to the previous one. Small void spaces inside a packing material affect the electric field strength. The enhancement can also lead to a change in the discharge characteristics, which can be different from the discharge condition of the bulk region (i.e. far from the solid material).{{cite journal|last1=Zhang|first1=Yu-Ru|last2=Van Laer|first2=Koen|last3=Neyts|first3=Erik C.|last4=Bogaerts|first4=Annemie|author4-link= Annemie Bogaerts |title=Can plasma be formed in catalyst pores? A modeling investigation|journal=Applied Catalysis B: Environmental|date=May 2016|volume=185|pages=56–67|doi=10.1016/j.apcatb.2015.12.009|hdl=10067/1298080151162165141|hdl-access=free}} The high intensity of the electric field can also lead to the production of different species that are not observed in the bulk.
• Change in the discharge type. Inserting a dielectric material in a discharge region leads to a shifting in the discharge type. From a filamentary regime a mixed filamentary/surface discharge is established. Ions, excited species and radicals are formed in a wider region if a surface discharge regime is present.{{cite journal|last1=Bednar|first1=Nikola|last2=Matović|first2=Jovan|last3=Stojanović|first3=Goran|title=Properties of surface dielectric barrier discharge plasma generator for fabrication of nanomaterials|journal=Journal of Electrostatics|date=December 2013|volume=71|issue=6|pages=1068–1075|doi=10.1016/j.elstat.2013.10.010}}

Catalyst effects on plasma are mostly related to the presence of a dielectric material inside the discharge region and do not necessarily require the presence of a catalyst.

• Anisothermal plasma
• Gliding Arc Plasmatron{{cite journal| pmid=28481058 | doi=10.1002/cssc.201700589 | volume=10 | title=Gliding Arc Plasmatron: Providing an Alternative Method for Carbon Dioxide Conversion | year=2017 | journal=ChemSusChem | pages=2642–2652 | last1 = Ramakers | first1 = M | last2 = Trenchev | first2 = G | last3 = Heijkers | first3 = S | last4 = Wang | first4 = W | last5 = Bogaerts | first5 = A| issue=12 | bibcode=2017ChSCh..10.2642R |author5-link= Annemie Bogaerts | hdl = 10067/1441840151162165141 | hdl-access = free }}

{{reflist}}

Category:Plasma types

Category:Food preservation