scholarly journals Plasma Catalysis: A Review of the Interdisciplinary Challenges Faced : Realising the potential of plasma catalysis on a commercial scale

2020 ◽  
Vol 64 (2) ◽  
pp. 138-147 ◽  
Author(s):  
Peter Hinde ◽  
Vladimir Demidyuk ◽  
Alkis Gkelios ◽  
Carl Tipton
Keyword(s):  
Reaction Rate ◽  
Scientific Literature ◽  
Catalytic Properties ◽  
Energy Levels ◽  
Atmospheric Plasma ◽  
Plasma Catalysis ◽  
Process Stream ◽  
Process Gas ◽  
Commercial Scale ◽  
Commercial Applications

The work presented here introduces the topic of plasma catalysis through selected work in scientific literature and commercial applications, as well as identifying some of the key challenges faced when attempting to utilise non-thermal atmospheric plasma catalysis across multidisciplinary boundaries including those of physics, chemistry and electrical engineering. Plasma can be generated by different methods at many energy levels and can initiate chemical reactions; the main challenges are to selectively initiate desirable reactions either within a process stream or at the surface of a material. The material, which may have intrinsic catalytic properties, the nature of the process gas and the geometry of the reactor will influence the products formed. Previous work has shown that the mechanism for plasma-initiated reactions can be different to that occurring from more traditional thermally stimulated reactions, which opens up possibilities of using different catalytic materials to optimise the reaction rate and product speciation. In addition, the influence of a plasma at the surface of a material and the effects that can be introduced will be discussed.

scholarly journals Plasma catalysis: A solution for environmental problems

2010 ◽  
Vol 82 (6) ◽  
pp. 1329-1336 ◽  
Author(s):  
J. Christopher Whitehead
Keyword(s):  
Energy Efficiency ◽  
Temperature Dependence ◽  
Operating Temperature ◽  
Atmospheric Plasma ◽  
Plasma Catalysis ◽  
Waste Gas ◽  
Gas Streams ◽  
Waste Gas Streams ◽  
Air Streams ◽  
By Products

The combination of a nonthermal, atmospheric plasma with a catalyst is investigated as a means of destroying pollutants in waste gas streams. Using the examples of dichloromethane (DCM) and toluene in air streams, it is shown that the destruction of the pollutant can be increased whilst lowering the operating temperature, giving increasing energy efficiency. Unwanted by-products can also be reduced selectively by appropriate choice of catalyst and of the plasma–catalyst configuration. By studying the temperature dependence of plasma catalysis, some ideas can be obtained about the nature of the interaction between plasma and catalyst in the processing.

scholarly journals Styrene and Bioaerosol Removal from Waste Air with a Combined Biotrickling Filter and DBD–Plasma System

2020 ◽  
Vol 12 (21) ◽  
pp. 9240
Author(s):  
Steffen Helbich ◽  
Daniel Dobslaw ◽  
Andreas Schulz ◽  
Karl-Heinrich Engesser
Keyword(s):  
Energy Levels ◽  
Biotrickling Filter ◽  
Dbd Plasma ◽  
Combined System ◽  
Waste Gas ◽  
Process Gas ◽  
Volatile Organic ◽  
Waste Air ◽  
Specific Input Energy ◽  
Non Thermal Plasma

A combined system of a biotrickling filter and a non-thermal plasma (NTP) in a downstream airflow was operated for 1220 days for treatment of emissions of styrene and secondary emissions of germs formed in the biological process. The biotrickling filter was operated at variable inlet concentrations, empty bed residence times (EBRT), type and dosage of fertilizers, irrigation densities, and starvation periods, while dielectric barrier discharge and corona discharge were operated at different specific input energy levels to achieve optimal conditions. Under these conditions, efficiencies in the removal of volatile organic compounds (VOCs), germs and styrene of 96–98%, 1–4 log units and 24.7–50.1 g C m−3 h−1 were achieved, respectively. Fluid simulations of the NTP and a germ emission-based clocking of the discharge reveal further energy saving potentials of more than 90%. The aim of an energy-efficient elimination of VOCs through a biotrickling filter and of secondary germ emissions by a NTP stage in a downstream airflow for potential re-use of purified waste gas as process gas for industrial application was successfully accomplished.

Influence of atmospheric plasma spraying on the solar photoelectro-catalytic properties of TiO2 coatings

2016 ◽  
Vol 189 ◽  
pp. 151-159 ◽  
Author(s):  
Sergi Dosta ◽  
Marco Robotti ◽  
Sergi Garcia-Segura ◽  
Enric Brillas ◽  
Irene Garcia Cano ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Catalytic Properties ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Tio2 Coatings

scholarly journals Surface and Catalytic Properties of NiO–Fe2O3 Solids Supported on Al2O3

1996 ◽  
Vol 13 (5) ◽  
pp. 409-421 ◽  
Author(s):  
G.A. El-Shobaky ◽  
A.M. Ghozza ◽  
N.M. Deraz
Keyword(s):  
Rate Constant ◽  
Reaction Rate ◽  
Catalytic Properties ◽  
Unit Area ◽  
Surface Characteristics ◽  
Reaction Rate Constant ◽  
Oxidation Of Co ◽  
Catalytic Activities ◽  
Surface Areas ◽  
Specific Surface Areas

A series of NiO–Fe2O3 catalysts supported on γ-Al2O3 was prepared. The effect of the NiO and Fe2O3 contents and the precalcination temperature on the surface and catalytic properties of the various solids has been investigated. The surface characteristics, viz. SBET, Vp and r, were determined using N2 adsorption conducted at –196°C. The catalytic activities of the various solids were studied using the oxidation of CO by O2 at temperatures in the range between 150°C and 400°C. The prepared solids were preheated in air at various temperatures between 400°C and 1000°C. The results obtained revealed that the SBET values of the different solids decrease progressively on increasing the precalcination temperature above 400°C due to sintering. The specific surface areas were also found to decrease on increasing both the NiO and Fe2O3 contents. The catalytic activities, expressed as reaction rate constant (k) and reaction rate constant per unit area (k), were found to decrease on increasing the precalcination temperature in the range 400–1000°C. Furthermore, the amounts of NiO and Fe2O3 in the different solids modified their catalytic activities in different manners.

scholarly journals Effects of γ-Irradiation on the Surface and Catalytic Properties of Co3O4/MgO Systems Aged for One Year

2002 ◽  
Vol 20 (10) ◽  
pp. 1037-1049 ◽  
Author(s):  
G.A. El-Shobaky ◽  
S.A. El-Molla ◽  
S.A. Ismail
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Rate Constant ◽  
Reaction Rate ◽  
Catalytic Properties ◽  
Reaction Rate Constant ◽  
Unit Surface Area ◽  
Γ Irradiation ◽  
Γ Rays ◽  
One Year

The effects of γ-rays (20–160 Mrad) on the surface and catalytic properties of two Co3O4/MgO systems were investigated. The formulae of the investigated solids were 0.05Co3O4/MgO and 0.2Co3O4/MgO, respectively, both prepared by the impregnation method and calcined at 500°C. The irradiated samples were left for one year in sealed tubes before any measurements were undertaken. γ-Irradiation of the investigated solids resulted in a progressive decrease in the particle size of the Co3O4 and MgO phases. This treatment also led to a measurable increase in the specific surface area of the treated solids to an extent proportional to the γ-ray dosage. Treatment of the Co3O4/MgO system with different doses of γ-rays brought about a significant increase in the catalytic activity expressed both as the reaction rate constant and as the reaction rate constant per unit surface area. However, the curve relating to the catalytic activity and dosage of γ-rays showed maxima located at 40 and 80 Mrad for samples having the formula 0.05Co3O4/MgO and 0.2Co3O4/MgO, respectively. Furthermore, samples exposed to 160 Mrad showed a larger catalytic activity than the unirradiated samples. The results demonstrate the role of γ-rays in inhibiting the deterioration of the catalytic activity of the investigated systems as a function of aging time. The irradiation process did not modify the activation energy of the catalyzed reaction but altered the concentration of active centres on the surfaces of the solids without changing their energetic nature.

Beryllium, Beryllium Alloys and the Theoretical Principles Affecting Alloy Formation with Beryllium

1946 ◽  
Vol 50 (426) ◽  
pp. 390-415 ◽  
Author(s):  
G. V. Raynor
Keyword(s):  
Melting Point ◽  
Modulus Of Elasticity ◽  
Large Scale ◽  
Alloy Formation ◽  
High Melting ◽  
High Modulus ◽  
High Melting Point ◽  
Commercial Scale ◽  
Commercial Applications

Beryllium, though of increasing application in the metallurgical and electrical industries, must still be classed as a relatively uncommon element. This would appear to be chiefly because no large scale application of the metal has yet been made; most commercial applications involve the addition of small amounts of beryllium to other metals, notably copper.If a large scale use for beryllium were to be discovered, there would be little difficulty in the production of sufficient metal to fulfil a reasonable .demand. Its ores are widespread, but unfortunately are seldom found in heavy local concentrations. The processing of these ores is somewhat difficult on a commercial scale, but not prohibitively so. Extensive researches have been made on these problems, because of the incentive given by the exceptional “lightness” of beryllium, its high melting point and particularly, by its high modulus of elasticity.

scholarly journals Investigation of IrO2/Pt Electrocatalysts in Unitized Regenerative Fuel Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
V. Baglio ◽  
C. D'Urso ◽  
A. Di Blasi ◽  
R. Ornelas ◽  
L. G. Arriaga ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Reaction Rate ◽  
Catalytic Properties ◽  
Reduction Process ◽  
Water Electrolysis ◽  
Gas Diffusion ◽  
Diffusion Characteristics ◽  
Pt Electrocatalysts ◽  
Diffusion Properties

IrO2/Pt catalysts (at different concentrations) were synthesized by incipient wetness technique and characterized by XRD, XRF, and SEM. Water electrolysis/fuel cell performances were evaluated in a 5 cm2single cell under Unitized Regenerative Fuel Cell (URFC) configuration. The IrO2/Pt composition of 14/86 showed the highest performance for water electrolysis and the lowest one as fuel cell. It is derived that for fuel cell operation an excess of Pt favours the oxygen reduction process whereas IrO2promotes oxygen evolution. From the present results, it appears that the diffusion characteristics and the reaction rate in fuel cell mode are significantly lower than in the electrolyser mode. This requires the enhancement of the gas diffusion properties of the electrodes and the catalytic properties for cathode operation in fuel cells.

Electrochemical treatment of copper cyanide wastewaters using stainless steel electrodes

1998 ◽  
Vol 38 (6) ◽  
pp. 261-268 ◽  
Author(s):  
L. Szpyrkowicz ◽  
F. Zilio-Grandi ◽  
S.N. Kaul ◽  
S. Rigoni-Stern
Keyword(s):  
Stainless Steel ◽  
Reaction Rate ◽  
Catalytic Properties ◽  
Electrochemical Treatment ◽  
Pure Metal ◽  
Order Reaction ◽  
First Order ◽  
Order Of Magnitude ◽  
Steel Electrodes ◽  
Weak Concentration

A study was carried out to define the best conditions for the simultaneous electroxidation of cyanides and recovery of copper as a metallic deposition on the cathode from weak concentration rinse wastewaters, using plate stainless steel electrodes. A direct electroxidation process and an indirect electroxidation in a chloriderich medium were tested at pH from 10 to 13. The results show that the process of the direct electroxidation is feasible and economically convenient if conducted at pH 13. It was possible to reduce copper concentration from 470 mg−1 by 79% in 1.5 h, at an energy consumption of 17 kWh kg−1 and to recover 335.3 mg of Cu as pure metal, electrodeposited on the cathode. The CuO film formed simultaneously on the anode had catalytic properties for CN− electroidation. The efficiency of the destruction of cyanides was in the same order of magnitude, with kinetics being of first order with respect to cyanide concentration (first order reaction rate k = 0.007 min−1).

Influence of the Surface Roughness of Plasma-Sprayed YSZ on LSM Cathode Polarization in Solid Oxide Fuel Cells

2008 ◽  
Vol 373-374 ◽  
pp. 641-644 ◽  
Author(s):  
Min Gao ◽  
Cheng Xin Li ◽  
Ming De Wang ◽  
Hua Lei Wang ◽  
Chang Jiu Li
Keyword(s):  
Surface Roughness ◽  
Solid Oxide Fuel Cells ◽  
Reaction Rate ◽  
Sol Gel ◽  
Atmospheric Plasma ◽  
Cathode Reaction ◽  
Lanthanum Strontium Manganate ◽  
Sol Gel Process ◽  
Plasma Sprayed ◽  
Ysz Electrolyte

Under SOFCs operating condition, the cathode reaction rate is determined by triple phase boundary (TPB) areas which are associated with the geometry of the interface between the cathode and the electrolyte. In this paper, YSZ electrolyte was deposited by atmospheric plasma spraying (APS). A nano-scaled lanthanum strontium manganate (LSM) cathode was prepared by sol-gel process on APS YSZ with different surface roughness to aim at increasing the TPB. The polarization curves of LSM cathode were characterized by potentiostat. The influence of the roughness of APS YSZ on the polarization of LSM cathode was investigated. It was found that the overpotential of the LSM cathode is significantly reduced with the increase of YSZ surface roughness.

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