scholarly journals CO2 Conversion in a Microwave Plasma Reactor in the Presence of N2: Elucidating the Role of Vibrational Levels

2015 ◽  
Vol 119 (23) ◽  
pp. 12815-12828 ◽  
Author(s):  
Stijn Heijkers ◽  
Ramses Snoeckx ◽  
Tomáš Kozák ◽  
Tiago Silva ◽  
Thomas Godfroid ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Plasma Reactor ◽  
Co2 Conversion ◽  
Vibrational Levels

Role of RF Power and Gas Mixture in Some Optical and Photoluminescence Properties of Dual-Plasma a-C:H Films

1998 ◽  
Vol 508 ◽  
Author(s):  
T. Heitz ◽  
C. Godet ◽  
J.E. Bouree ◽  
B. Drevillon ◽  
V. Chu ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Plasma Reactor ◽  
Carbon Films ◽  
Polymer Chains ◽  
Visible Range ◽  
Cross Linking ◽  
Rf Power ◽  
Photoluminescence Properties ◽  
Hydrogenated Amorphous

AbstractElectronic properties of polymer-like hydrogenated amorphous carbon films, grown in a RF-assisted microwave plasma reactor, have been studied using optical absorption and photoluminescence spectroscopies. Using a Forouhi-Bloomer parametrization of π-π* transitions, two regimes are evidenced for increasing C atom density : a decrease of the optical gap Eππ* at constant (H/H+C) content attributed to sp2C clustering, followed by some H elimination with minor changes in Eππ* due to cross-linking of polymer chains. The photoluminescence efficiency in the visible range (peak at ≈ 2.3 eV) is found to decrease over four orders of magnitude at the onset of the cross-linking regime. This quenching is attributed to stress-induced non-radiative centers.

DBD plasma reactor for oxidative decomposition of Chlorobenzene

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
L. Sivachandiran ◽  
J. Karuppiah ◽  
Ch. Subrahmanyam
Keyword(s):  
Barrier Discharge ◽  
Copper Wire ◽  
Plasma Reactor ◽  
Aluminum Foil ◽  
Low Flow ◽  
Dbd Plasma ◽  
Silver Paste ◽  
Oxidative Decomposition ◽  
Gaseous Products

Abstract Oxidative decomposition of chlorobenzene diluted in air was carried out in a dielectric barrier discharge reactor. In order to understand the role of the ground electrode, various reactor configurations were tested. Among silver paste, copper wire and aluminum foil tested as the outer electrodes, typical results indicated the best performance of silver paste, probably due to uniform distribution of microdischarges. Likewise, low flow rates gave better conversion and selectivity to gaseous products.

scholarly journals CALCULATIONS OF ION TRAJECTORIES AT MAGNETOPLASMA SEPARATION AND EXPERIMENTS WITH POLYATOMIC GASES

2017 ◽  
Vol 57 (1) ◽  
pp. 71-77
Author(s):  
Vladimir Yuferov ◽  
Sergey Shariy ◽  
Tetiana Tkachova ◽  
Vyacheslav Katrechko ◽  
Alexander Svichkar ◽  
...  
Keyword(s):  
Discharge Current ◽  
Energy Input ◽  
Pulsed Discharge ◽  
Polyatomic Gases ◽  
Constant Energy ◽  
Mixture Separation ◽  
Low Emission ◽  
Vibrational Levels ◽  
Nonlinear Character

Calculated trajectories of ions with different masses, indicating the possibility of a mixture separation, are obtained. Comparative experiments for plasma of monatomic and polyatomic gases (Ar, N<sub>2</sub>, CO<sub>2</sub>), upon combination of pulsed discharge with a stationary one with incandescent cathode, are carried out. The oscillograms of discharge current and voltage at low emission currents and a constant energy input show that energy is spent on other processes different from ionization. With an increase of emission current, the nonlinear character of the discharge current and voltage, which may be indicative of the role of dissociation and vibrational levels in energy consumption, is observed. In addition, there is connection between the number of atoms in molecule and the values of maximum discharge current and the pressure of injected gas.

Energy coupling efficiency of a hydrogen microwave plasma reactor

2001 ◽  
Vol 89 (3) ◽  
pp. 1544 ◽  
Author(s):  
M. H. Gordon ◽  
X. Duten ◽  
K. Hassouni ◽  
A. Gicquel
Keyword(s):  
Microwave Plasma ◽  
Plasma Reactor ◽  
Coupling Efficiency ◽  
Energy Coupling

scholarly journals Design and characterization of an electromagnetic-resonant cavity microwave plasma reactor for atmospheric pressure carbon dioxide decomposition

2018 ◽  
Vol 16 (2) ◽  
pp. 1800153 ◽  
Author(s):  
Sina Mohsenian ◽  
Shyam Sheth ◽  
Saroj Bhatta ◽  
Dassou Nagassou ◽  
Daniel Sullivan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Resonant Cavity

Nanoparticles generated by combining hot wall and microwave plasma chemical vapor synthesis

MRS Advances ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 213-218
Author(s):  
Alexander Levish ◽  
Markus Winterer
Keyword(s):  
Iron Oxide ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Chemical Vapor ◽  
Process Window ◽  
Chemical Vapor Synthesis ◽  
Second Stage ◽  
Structure Surface ◽  
Oxide Phases ◽  
Precursor Decomposition

ABSTRACTControlling the oxidation state of iron and the crystal structure of iron containing compounds is the key to improved materials such as iron oxide nanoparticles for cancer treatment or heterogeneous catalysis. Iron oxides contain iron in different oxidation states and form different phases for one valence state (α-Fe3+2O2-3, β- Fe3+2O-32, etc.). Chemical vapor synthesis (CVS) allows the reproducible production of pure nanocrystals with narrow size distribution where particle formation and growth take place in the gas phase. Through the controlled variation of synthesis parameters CVS enables the synthesis of diverse iron oxide phases. In this study the energy for the CVS process is supplied by a hot wall furnace and a microwave plasma. The advantage of an plasma reactor as the first CVS stage is the fast and complete precursor decomposition at low temperatures. This results in a larger process window for the hot wall reactor in the second stage. The nanoparticles are examined regarding their structure, surface and valence by XRD and TEM.

scholarly journals Composition, Mixing State and Water Affinity of Meteoric Smoke Analogue Nanoparticles Produced in a Non-Thermal Microwave Plasma Source

2018 ◽  
Vol 232 (5-6) ◽  
pp. 635-648 ◽  
Author(s):  
Mario Nachbar ◽  
Denis Duft ◽  
Alexei Kiselev ◽  
Thomas Leisner
Keyword(s):  
Silicon Oxide ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Stoichiometric Composition ◽  
Plasma Source ◽  
Mixing State ◽  
Iron Oxide Particles ◽  
Pure Silicon ◽  
Meteoric Smoke ◽  
Water Affinity

Abstract The article reports on the composition, mixing state and water affinity of iron silicate particles which were produced in a non-thermal low-pressure microwave plasma reactor. The particles are intended to be used as meteoric smoke particle analogues. We used the organometallic precursors ferrocene (Fe(C5H5)2) and tetraethyl orthosilicate (TEOS, Si(OC2H5)4) in various mixing ratios to produce nanoparticles with radii between 1 nm and 4 nm. The nanoparticles were deposited on sample grids and their stoichiometric composition was analyzed in an electron microscope using energy dispersive X-ray spectroscopy (EDS). We show that the pure silicon oxide and iron oxide particles consist of SiO2 and Fe2O3, respectively. For Fe:(Fe+Si) ratios between 0.2 and 0.8 our reactor produces (in contrast to other particle sources) mixed iron silicates with a stoichiometric composition according to FexSi(1−x)O3 (0≤x≤1). This indicates that the particles are formed by polymerization of FeO3 and SiO3 and that rearrangement to the more stable silicates ferrosilite (FeSiO3) and fayalite (Fe2SiO4) does not occur at these conditions. To investigate the internal mixing state of the particles, the H2O surface desorption energy of the particles was measured. We found that the nanoparticles are internally mixed and that differential coating resulting in a core-shell structure does not occur.

Effect of N2 and Ar on CO2 conversion with segmented micro-plasma reactor

2021 ◽  
Author(s):  
Baowei Wang ◽  
Xiaoyan Li ◽  
Xiaoxi Wang ◽  
Huijuan Su ◽  
Bo Zhang
Keyword(s):  
Plasma Reactor ◽  
Co2 Conversion

scholarly journals Plasma Catalytic Conversion of CH4 to Alkanes, Olefins and H2 in a Packed Bed DBD Reactor

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 774
Author(s):  
Mohammadreza Taheraslani ◽  
Han Gardeniers
Keyword(s):  
Barrier Discharge ◽  
Plasma Reactor ◽  
Packed Bed ◽  
Reaction Pathways ◽  
Ambient Conditions ◽  
Alumina Catalyst ◽  
Dbd Plasma ◽  
Hydrogenation Reactions ◽  
Notable Increase

Methane is activated at ambient conditions in a dielectric barrier discharge (DBD) plasma reactor packed with Pd/γ-alumina catalyst containing different loadings of Pd (0.5, 1, 5 wt%). Results indicate that the presence of Pd on γ-alumina substantially abates the formation of deposits, leads to a notable increase in the production of alkanes and olefins and additionally improves the energy efficiency compared to those obtained for the non-packed reactor and the bare γ-alumina packed reactor. A low amount of Pd (0.5 and 1 wt%) favors achieving a higher production of olefins (mainly C2H4 and C3H6) and a higher yield of H2. Increasing Pd loading to 5 wt% promotes the interaction of H2 and olefins, which consequently intensifies the successive hydrogenation of unsaturated compounds, thus incurring a higher production of alkanes (mainly C2H6 and C3H8). The substantial abatement of the deposits is ascribed to the role of Palladium in moderating the strength of the electric and shifting the reaction pathways, in the way that hydrogenation reactions of deposits’ precursors become faster than their deposition on the catalyst.

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