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This review presents an analysis of the existing concepts for the utilization of electric power for heating chemical reactors, primarily those designed for heterogeneous catalytic processes. The paper provides a brief outline of major electric heating methods in the context of chemical applications, mentions important examples of the industrial implementation of electric heating, and evaluates the prospects for industrial use of electric heating instead of conventional heating systems. [ABSTRACT FROM AUTHOR]

Quenched Co-based ribbon strips are widely used in the fields of magnetic amplifier, magnetic head material, magnetic shield, electric reactor, inductance core, sensor core, anti-theft system label, and so on. In this study, Co-based composite CoFeNiSiB ribbon strips with a micron width were fabricated by micro-electro-mechanical systems (MEMS) technology. The carbon and FeCoGa nanofilms were deposited for surface modification. The effect of carbon and FeCoGa nanofilm coatings on the crystal structure, surface morphology, magnetic properties, and magnetoimpedance (MI) effect of composite ribbon strips were systematically investigated. The results show that the surface roughness and coercivity of the composite ribbon strips are minimum at a thickness of the carbon coating of 60 nm. The maximum value of MI effect is 41% at 2 MHz, which is approximately 2.4 times greater than plain ribbon and 1.6 times greater than FeCoGa-coated composite ribbon strip. The addition of a carbon layer provides a conductive path for high frequency currents, which effectively reduces the characteristic frequency of the composite ribbon strip. The FeCoGa coating is able to close the flux path and reduce the coercivity, which, in turn, increases the transverse permeability and improves the MI effect. The findings indicate that a successful combination of carbon layer and magnetostrictive FeCoGa nanofilm layer can improve the MI effect and magnetic field sensitivity of the ribbon strips, demonstrating the potential of the composite strips for local and micro area field sensing applications. [ABSTRACT FROM AUTHOR]

The paper presents a method, implemented for the first time, for the thermal synthesis of hafnium carbide powder using a DC arc discharge initiated in the open-air atmosphere. Based on the results of the series of experiments, the dependences of the current strength of the power source and the time of thermal treatment on the phase composition of the resulting powder product were established. Required parameters have been determined to ensure the synthesis of a powder containing ~98 mass % of the cubic phase of hafnium carbide: heat treatment of the initial mixture containing the stoichiometric ratio of hafnium to carbon for 60 s at a current of 220 A. The size, shape, and substructure of particles of the synthesized carbide are characterized. The differential thermal analysis carried out in an oxidizing medium showed that the obtained hafnium carbide powder is oxidized most intensively at a temperature of ~700°C. [ABSTRACT FROM AUTHOR]

Copyright of Informatics Control Measurement in Economy & Environment Protection / Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska is the property of Lublin University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Methane pyrolysis in liquid metals is a worth-developing process for CO 2 -free hydrogen production. This study investigates methane pyrolysis in molten tin and highlights the impact of several parameters on methane conversion (X CH4) in a novel hybrid solar/electric bubbling reactor. Temperature (1200–1300 °C), total inlet gas flow rate (Q 0 = 0.25–0.5 NL/min), melt height (H im = 60-120-235 mm) and hybridization are addressed. Increasing the temperature from 1200 °C to 1300 °C (Q 0 = 0.25 NL/min and H im = 120 mm) improves X CH4 (32% vs. 69%). Increasing Q 0 from 0.25 to 0.5 NL/min (T = 1200 °C and H im = 120 mm) reduces X CH4 (19% vs. 9%). Doubling the melt height (H im from 60 to 120 mm) increases the residence time of bubbles, which increases X CH4 (7% vs. 19%). A customized sparger is also tested and shows little effect, probably because the holes are relatively large (1 mm diameter). An immersed bed of steel particles (0.2–0.4 mm diameter) instead shows improved results (X CH4 = 32%) at a relatively low temperature (1100 °C). Continuous reactor operation at 1300 °C without clogging is also confirmed. Analysis of carbon accumulated at melt surface during molten media methane pyrolysis reveals a tin-containing sheet-like structure. [Display omitted] • Solar methane pyrolysis in molten metal allows turquoise hydrogen production. • Continuous reactor operation was proved through a run of 4 h at 1300 °C. • The total amount of produced carbon floating on the liquid tin surface was recovered. • Hybrid heating led to 92% CH 4 conversion with 120 mm liquid height at 1200 °C. • Increasing heated height of molten tin enhanced bubbles residence time in the hot zone and CH 4 conversion. [ABSTRACT FROM AUTHOR]

One of the main features of microwave plasma reactors is the electric field structure in the resonant cavity, which must be both intense and uniform in front of the substrate. For this reason, transverse magnetic modes are often used, especially axisymmetric modes because they produce an axisymmetric plasma. Microwave plasma reactors can be differentiated according to the chosen mode, because this has a direct influence on the diamond film growth process, among other features such as the coupling technique and the used quartz window. Another attractive characteristic of said reactors is obtaining large activation areas of the plasma. In this paper, we propose a microwave plasma reactor based on the TM112 cylindrical mode, which is subject to a computational study. Unlike axisymmetric modes, which activate the plasma on the cavity axis, the TM112 cylindrical mode presents two activation plasma areas. The reactor was designed following the methodology described by Silva et al., and using the Plasma, Radiofrequency (RF), and Heat transfer modules of the software COMSOL Multiphysics. The obtained results are presented in two stages. The first one is related to the initial electric field distribution of the TM112 mode. Next, the generation of the hydrogen plasma was simulated from the interaction of H2 gas with the TM112 microwave field. The plasma activation process is described in detail from graphics of the time evolution of the electron density, hydrogen density, and their respective temperatures until a steady state is reached. Additionally, the influence of the pressure on the concentration and the temperature of both electrons and gas in a steady state is analyzed. The presented results can be useful for the design of plasma reactors for diamond deposition. [ABSTRACT FROM AUTHOR]

We studied the disperse characteristics of atmospheric aerosols and the degree of their contamination with heavy metals and organic substances. Aerosol samples were collected at a road intersection in one district of Kyiv at different heights from the asphalt surface in April and July 2019. The concentration of heavy metals (Сu, Cr, and Pb) on aerosol filters was determined using atomic absorption spectrometry with electrothermal atomization. The levels of copper and chromium ions increase by 20–40 times, while the level of lead increases by 100–150 times compared to the background value; the concentration of organic carbon increases by 2–5 times depending on the time of day and height from the asphalt surface. The aerosol mixture was processed in a pulsed corona electric discharge reactor, leading to the destruction of organic compounds, yielding over 80% purification of the aerosol mixture from pollutants, and improving the light transmission by 78–83%. Electric-discharge processing of aerosols can be used in industrial installations to decrease the gas contamination of workspace and clean air volumes from dust before they are released into the atmosphere. [ABSTRACT FROM AUTHOR]

Hybrid biological-inorganic (HBI) systems comprising inorganic water-splitting catalysts and aerobic hydrogen-oxidizing bacteria (HOB) have previously been used for CO 2 conversion. In order to identify new biocatalysts for CO 2 conversion, the present study used an HBI system to enrich HOB directly from environmental samples. Three sediment samples (from a brackish water pond, a beach, and a tide pool) and two activated sludge samples (from two separate sewage plants) were inoculated into HBI systems using a cobalt phosphorus (Co–P) alloy and cobalt phosphate (CoPi) as inorganic catalysts with a fixed voltage of 2.0 V. The gas composition of the reactor headspaces and electric current were monitored. An aliquot of the reactor medium was transferred to a new reactor when significant consumption of H 2 and CO 2 was detected. This process was repeated twice (with three reactors in operation for each sample) to enrich HOB. Increased biomass concomitant with increased H 2 and CO 2 consumption was observed in the third reactor, indicating enrichment of HOB. 16S rRNA gene amplicon sequencing demonstrated enrichment of sequences related to HOB (including bacteria from Mycobacterium , Hydrogenophaga , and Xanthobacter genera) over successive sub-cultures. Finally, four different HOB belonging to the Mycobacterium , Hydrogenophaga , Xanthobacter , and Acidovorax genera were isolated from reactor media, representing potential candidates as HBI system biocatalysts. [ABSTRACT FROM AUTHOR]

Methane pyrolysis is a transitional technology for environmentally benign hydrogen production with zero greenhouse gas emissions, especially when concentrated solar energy is the heating source for supplying high-temperature process heat. This study is focused on solar methane pyrolysis as an attractive decarbonization process to produce both hydrogen gas and solid carbon with zero CO2 emissions. Direct normal irradiance (DNI) variations arising from inherent solar resource variability (clouds, fog, day-night cycle, etc.) generally hinder continuity and stability of the solar process. Therefore, a novel hybrid solar/electric reactor was designed at PROMES-CNRS laboratory to cope with DNI variations. Such a design features electric heating when the DNI is low and can potentially boost the thermochemical performance of the process when coupled solar/electric heating is applied thanks to an enlarged heated zone. Computational fluid dynamics (CFD) simulations through ANSYS Fluent were performed to investigate the performance of this reactor under different operating conditions. More particularly, the influence of various process parameters including temperature, gas residence time, methane dilution, and hybridization on the methane conversion was assessed. The model combined fluid flow hydrodynamics and heat and mass transfer coupled with gas-phase pyrolysis reactions. Increasing the heating temperature was found to boost methane conversion (91% at 1473 K against ~100% at 1573 K for a coupled solar-electric heating). The increase of inlet gas flow rate Q0 lowered methane conversion since it affected the gas space-time (91% at Q0 = 0.42 NL/min vs. 67% at Q0 = 0.84 NL/min). A coupled heating also resulted in significantly better performance than with only electric heating, because it broadened the hot zone (91% vs. 75% methane conversion for coupled heating and only electric heating, respectively). The model was further validated with experimental results of methane pyrolysis. This study demonstrates the potential of the hybrid reactor for solar-driven methane pyrolysis as a promising route toward clean hydrogen and carbon production and further highlights the role of key parameters to improve the process performance. [ABSTRACT FROM AUTHOR]

• Key dimension parameters of the PMG were obtained and the simulation model of PMG was established. • Comprehensive research on the electromagnetic field and loss calculation were performed. • The cooling paths of the PMG were designed and the resulting temperature profiles were calculated. • Different cooling schemes were compared and the appropriate cooling advice was proposed. The closed Brayton cycle (CBC) system is a prime energy conversion technology to convert heat from the reactor to electric power for space missions due to its light weight, compact and stable operation. The CBC system incorporates a permanent magnet generator (PMG) mounted on the CBC shaft with the turbine and compressor. To ensure safe operation of the CBC system, a small fraction of the working fluid is used to provide the required cooling. In this study, four different cooling schemes used in CBC system are concluded and the key dimensions of the PMG are obtained through mechanical design theory and electromagnetic theory. Comprehensive research on the electromagnetic field and loss calculation is then performed. Furthermore, the cooling paths of the PMG are designed and the resulting temperature profiles are calculated. Finally, different cooling schemes are compared and the appropriate cooling advice is proposed. [ABSTRACT FROM AUTHOR]

This study developed a prototype of a wire-plate air bubbling plasma reactor that can be easily scaled up for wastewater treatment. The electrical characteristics, including the discharge current and average power consumed, of the developed reactor were deeply investigated at different operating parameters and solution conductivities. The performance of the reactor was examined on the basis of energy efficiency and methylene blue (MB) decoloration efficiency. Moreover, the removal of the total organic carbon and the changes of the physicochemical properties of solution, including pH, conductivity, and temperature, were evaluated. The analysis of current discharge and average power consumed showed that the discharge mode in the present reactor is a filamentary streamer. Interestingly, the solution conductivity had no effect on the average power consumed at low applied voltages, due to confinement of the discharge in a small area surrounding the discharge electrode in the gas phase. However, at relatively high voltages, the effect of conductivity on the average power consumed was noticeable, yet it had no effect on the decoloration efficiency at the same average power. The present reactor showed a high energy-efficiency value of 42 g/kWh at 50% decoloration of 30 mg/l MB solution, but it dropped to 14 g/kWh at 97% decoloration. A first-order kinetics model described well the decoloration reaction rates and the overall rate constant correlated linearly to the average power. [ABSTRACT FROM AUTHOR]

This work is aimed at developing a novel apparatus that combines inclined plate settler (IPS) and electrocoagulation (EC) to improve the emulsified oil removal efficiency with lower energy consumption. The combined process (IPS-EC) was optimized at various reactor configurations and electric field parameters of the EC process in dynamic oily wastewater treatment experiments. The results indicated that the effective removal of oil from wastewater was achieved due to the synergistic effect of EC and IPS at very low energy consumptions. The IPS could remove 74.1%±1.1% of the oil droplets from the oily wastewater. When an external pulsed direct current was applied to the metallic plates of IPS, the oil removal efficiency of IPS-EC increased to 97.0%±0.9% at a current density of 1 mA/cm2, pulsed frequency of 2000 Hz, and duty ratio of 0.9. Uniform pitting corrosion occurred on the aluminum electrode surface in a pulsed direct current waveform, which favors mitigation of electrode passivation. The energy consumption of IPS-EC was recorded as 0.66 kW.h per kilogram of oil, which is much lower than the conventional EC. The results provide a basis for the treatment of highly emulsified oily wastewater using the IPS-EC method. [ABSTRACT FROM AUTHOR]

Gasification is considered a promising option for harnessing energy potential from agricultural waste, such as rice husks. This paper presents a 10-kW rice husk fixed bed gasifier system. This system is an improved version of a prototype previously developed by our research group. Some of the optimized features added to the gasifier include the use of a circular air intake, an improved gas cleaning system, and electric motors that are regulated by a programmable logic controller. Keeping the gasifier system's operation stable is critical for producing high-quality synthetic gas (syngas). Therefore, performance evaluation of the presented gasifier system was conducted, and the resulting syngas outputs were analyzed. The evaluation also included an investigation into the performance of the motors, particularly those used for feeding and char removal, which are critical components of the system. The results showed that the improved gasifier system was stable with a proper feedstock. A discussion of the parameters affecting the composition of the synthetic gas is also presented. [ABSTRACT FROM AUTHOR]

Because reactors applied to electric vehicles are typically driven under a DC-biased current, a constant inductance property is required. When a high-performance DC-biased reactor is designed, the topology optimization (TO) is an effective design method owing to the high degree of structural change in the magnetic circuit. However, there exists no report regarding the TO method in the steady-state time domain with magnetic nonlinearity. In this paper, based on the time-domain adjoint variable method, a novel sensitivity analysis approach for the steady-state time domain with thorough consideration of the magnetic saturation is proposed. Through the proposed method, the TO of the iron core and winding structures in a pot-type reactor was carried out to enhance the DC-biased characteristics. Furthermore, the eddy current loss occurring on the aluminum plate installed outside the reactor was suppressed by the multi-objective TO. The interesting structure of a pot-type reactor that enhanced the DC-biased characteristics and reduced the eddy current loss on the outer conductor plate was also illustrated. [ABSTRACT FROM AUTHOR]

A novel supercritical water gasification (SCWG) system using hydrothermal flame as internal heat source (HSCWG) for oily sludge treatment was proposed to achieve rapid preheating and promote gasification rate. The proposed system was firstly simulated using Aspen Plus 11, and the simulation model was validated by comparison with experimental data. The exergy input, output, and destruction for the HSCWG are far smaller than those for the traditional SCWG system using hot water as heat source (TSCWG). The oxidation reactor and electric heater contribute to the maximum exergy destructions in the HSCWG and TSCWG, with the exergy distribution coefficients of 30.80 % and 37.16 %, respectively, indicating the preheating method is a key factor affecting the energy consumption and system efficiency. Lower exergy efficiencies are present at higher gasification temperatures, indicating more exergy destructions are present in the oxidation reactor and electric heater. Moreover, the net operating cost for the TSCWG increases significantly with increasing gasification temperature, which is far higher than that for the HSCWG. The HSCWG is more competitive for the treatment of oily sludge compared with the TSCWG. Fuel concentration adjustment is more efficient than fuel flow adjustment in the regulation of the gasification temperature. • A novel HSCWG was proposed to achieve rapid preheating and promote gasification rate. • SCWG of oily sludge for hydrogen-rich syngas production was simulated using Aspen Plus. • Preheating method is a key factor affecting energy consumption and system efficiency. • HSCWG is more efficient and economical for oily sludge treatment compared with TSCWG. • Adjusting fuel concentration is an efficient way for gasification temperature regulation. [ABSTRACT FROM AUTHOR]

• This study presents a comprehensive multi-physics FEM analysis of an air-core reactor within a solid-state fault current limiter, focusing on thermal, electromagnetic, and electrostatic aspects under both normal and fault conditions of the test system. • FEM model-electric circuit coupling is validated with a 380 V test prototype, and the current results of the high-voltage simulation are supported by PSCAD results to show simulation accuracy. • During the thermal studies, convection, radiation and convection mechanism applied to air-core reactor and results shows that thermal stability is maintained during the fault limiting mode. • Analysis revealed significant increases in electric field, magnetic flux density and forces acting on the air-core reactor's windings during the fault condition of the test system. • The solid-state FCL topology, incorporating the modeled air-core reactor, reduced the fault current by 85.32 % during the fault scenarios within high-voltage simulations. This study presents a comprehensive multi-physics modelling of an air-core reactor operating within a solid-state fault current limiter. By utilizing an air-core reactor in the solid-state fault current limiter, it is aimed to avoid magnetic saturation and assess a conventional fault current limiting device within a contemporary fault current limiter topology. Within the employed fault current limiter topology, the air-core reactor not only limits fault current during grid faults but also carries nearly the entire network current under normal operational conditions. Therefore, the performance of air-core reactor is investigated through thermal, electromagnetic and electrostatic aspects for normal and fault conditions. A 380 V test prototype is employed to validate the coupling of reactor model and electric circuit dynamics in the simulations. Furthermore, current results of high voltage simulations are supported by PSCAD results to reveal the results accuracy. During the operation of air-core reactor in normal and fault cases, the distribution of heat originating from eddy and resistive losses was examined through convection, radiation and conduction mechanisms. Moreover, the electric field intensities affecting the reactor are obtained for different operating conditions through electrostatic analysis, whereas the electromagnetic analysis reveals the magnetic flux densities and magnetic forces acting on the reactor. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plasma treatment without the use of vacuum equipment. • The mixture of various types of glass waste can be used in electric arc processing. • Silicon carbide was obtained from a mixture of glass waste of various origins. The paper presents the results of the experimental studies addressing the production of silicon carbide from glass waste by electric arc plasma processing. A feature of the method is the possibility of its implementation without the use of vacuum equipment. It is possible due to the effect of self-shielding of the reaction volume from atmospheric oxygen. This approach significantly simplifies the design of the electric arc reactor and its performance. After plasma processing of various types of glass waste (such as bottle glass, window glass, medical glass, quartz glass, parts of worn-out scientific and industrial equipment), silicon carbide based material was produced. Silicon carbide was obtained from a mixture of various glass waste at a current 200 A, where blend was first purified from unbound carbon and then was consolidated by spark plasma sintering at 1800 °C and 60 MPa pressure for 10 min. As a result, a ceramic bulk sample was fabricated from a mixture of glass waste of various origin. Such sample was characterized with hardness of 14.8 GPa, and attained density of 92.5 %. Despite a possible increase in the density due to impurities and inhomogeneities, the hardness of the fabricated sample is comparable to that of other silicon carbide based materials, including commercial ones. Since the hardness of the produced silicon carbide based material is comparable to that of commercial materials, the use of glass waste of various origin could be feasible for synthesis of silicon carbide based powders. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A layer of regolith with a 1.35% Al content was irradiated from the side of the reactor supporting plate with a microwave pulse with an intensity of 10–15 kW cm–2 (the wavelength is 4 mm) and a duration of 1.5 ms and 3.5 ms. An air rarefaction of ~76 Torr was created in the reactor. A gas discharge occurred when the ratio E0 /N0 = 1.03 × 10–15 V cm2 was exceeded (E0 is the electric field at the reactor axis, N0 is the concentration of molecules in air). The discharge above the regolith surface occurred only after microwave breakdown of the air with a delay of more than 200 μs. In this case, evaporation of regolith particles and their ejection into the reactor volume took place. It was found that an increase in the microwave pulse duration to 3.5 ms leads to long-term sparking of regolith particles. This can be explained by the energy release during the reaction 2Al + 3FeO → Al2O3 + 3Fe initiated by the evaporation of iron oxide under the combined action of microwave radiation and UV radiation from the gas discharge. [ABSTRACT FROM AUTHOR]

The noise and vibration of large oil-immersed reactor is usually controlled and reduced by using high-strength pretensioned steel rods to fasten iron cores. But the effect of uneven temperature increase in the reactor on the pretension relaxation of steel rods is rarely discussed in previous literatures. A combined fastening device of high-strength steel rod and disc spring is designed to conduct temperature experiment in this paper. And three-dimensional (3D) finite element model is developed to reproduce the experiment process. After the numerical simulation method is verified, finite element analysis of a real BKD-6700/20 oil-immersed reactor is performed. The prestress loss proportion of the high-strength pretensioned steel rods in the oil-immersed reactor under practical operating state is 17.91 % owing to its uneven temperature rise, which can result in significantly weakening of its vibration and noise reduction function. [ABSTRACT FROM AUTHOR]

Direct voltage fluctuations due to the presence of relatively large DC reactors (as an essential part of HVDC breakers), lack of inertia, and unwanted frequency fluctuations in the AC side of HVDC grids, have major consequences on the stability of HVAC/HVDC grids. The use of the DC Power System Stabilizer (DC‐PSS) can damp and eliminate voltage oscillations caused by the presence of the DC reactors. However, DC‐PSS cannot address the issues of inertia and unwanted frequency fluctuations. A method to improve inertia is proposed here that can operate well with the droop controller, and DC‐PSS does not interfere with power‐sharing and does not interact with any of these elements. Since the presence of a droop controller in HVAC/HVDC grids associates with power and direct voltage, the method proposed here can improve direct voltage fluctuations by eliminating severe power peaks. Moreover, this method does not change the voltage level of the entire system, so there is no need to change the set‐points of controllers. In addition, all parameters of the controllers are tuned by an intelligent algorithm, and the Participation factor (PF) scheme is used to find the proper placement of the proposed controller. [ABSTRACT FROM AUTHOR]

We clarify the difference between the SiH4 consumption efficiency η and the SiH4 depletion fraction D, as measured in the pumping line and the actual reactor of an industrial plasma-enhanced chemical vapor deposition system. In the absence of significant polysilane and powder formation, η is proportional to the film growth rate. Above a certain powder formation threshold, any additional amount of SiH4 consumed translates into increased powder formation rather than into a faster growing Si film. In order to discuss a zero-dimensional analytical model and a two-dimensional numerical model, we measure η as a function of the radio frequency (RF) power density coupled into the plasma, the total gas flow rate, the input SiH4 concentration, and the reactor pressure. The adjunction of a small trimethylboron flow rate increases η and reduces the formation of powder, while the adjunction of a small disilane flow rate decreases η and favors the formation of powder. Unlike η, D is a location-dependent quantity. It is related to the SiH4 concentration in the plasma cp, and to the phase of the growing Si film, whether the substrate is glass or a c-Si wafer. In order to investigate transient effects due to the RF matching, the precoating of reactor walls, or the introduction of a purifier in the gas line, we measure the gas residence time and acquire time-resolved SiH4 density measurements throughout the ignition and the termination of a plasma. [ABSTRACT FROM AUTHOR]

• Dy addition reduces Ni crystallite size and improve its dispersion on Ni/SiC-SiO 2. • 0.5 %Dy-10 %Ni/SiC-SiO 2 achieves 100 % CH 4 selectivity and 73.9 % CO 2 conversion at 350 °C. • Microwave heating outperforms electric, yielding higher CO 2 conversion. • Extreme SiC dilution hampers CO 2 conversion and CH 4 selectivity in both reactors. • Carbon formation in the microwave reactor quantified at only 0.0099 mg C /g cat /h. In this work, Dy-promoted Ni/SiC-SiO 2 catalysts with varied Dy loadings (0–1 %) were developed using the wet impregnation method and evaluated for their effectiveness in CO 2 methanation. The characterization results reveal that Dy addition can reduce the Ni crystallite size, enhance the dispersion of active phase and increase the catalyst's reducibility. Among the prepared catalysts, the 0.5 %Dy-10 %Ni/SiC-SiO 2 demonstrated the highest CH 4 selectivity (100 %) and CO 2 conversion (73.9 %) at 350 °C owing to its highest basic sites and H 2 chemisorption capacity. The performance of this Dy-promoted catalyst diluted with different amounts of SiC, which was employed as a microwave susceptor and high thermal conductive dilution material, was also investigated in both microwave and electric reactor. Microwave heating leads to higher CO 2 conversion compared to electric heating, regardless of reaction temperature and dilution factor due to selective heating and the random occurrence of hot spots, which are usually considered as micro-plasmas in the catalyst bed. However, further increase quantity of SiC decreased both CO 2 conversion and CH 4 selectivity regardless of heating method. This may be attributed to the appearance of extreme overheating and the absence of gentle overheating with increased amount of SiC in the microwave and electric reactors, respectively. The temperature-programmed oxidation results demonstrated that carbon deposition on the 0.5 %Dy-10 %Ni/SiC-SiO 2 catalyst during 30 h of reaction can be significantly suppressed by microwave. [ABSTRACT FROM AUTHOR]

A CH3F:O2 (50%:50%) inductively coupled discharge, sustained in a compact plasma reactor, was investigated as a function of power (20-400 W) and pressure (9-30 mTorr), using optical emission spectroscopy and Langmuir probe measurements. The electron density increased linearly with power but only weakly with pressure. The effective electron temperature was nearly independent of power and pressure. The gas temperature, obtained from the rotational structure of N2 (C → B) optical emission, increased from 400 to 900 K as a function of inductive mode power between 75 and 400 W at 10 mTorr. For constant feed gas flow, the absolute H, F, and O atom densities, estimated by optical emission rare gas actinometry, increased linearly with power. The absolute number density ratios H/Ar, F/Ar, and O/Ar, increased, decreased, and remained constant, respectively, with pressure. The H-atom density was estimated to be 5.4 × 1013 cm-3 at 400 W and 10 mTorr (gas temperature = 900 K), implying a high degree of dissociation of the CH3F feedstock gas. The F and O atom number densities were much lower (8.3 × 1012 cm-3 and 5.9 × 1012 cm-3, respectively) for the same conditions, suggesting that most of the fluorine and oxygen is contained in reaction products HF, CO, CO2, H2O, and OH. The relative number densities of HF, CO, and CO2 were observed to first rapidly increase with power, and then reach a plateau or decay slightly at higher power. Reaction mechanisms were proposed to explain the observed behavior of the number density of F and HF vs. power and pressure. [ABSTRACT FROM AUTHOR]

Summary: The cogasification experiments were carried out by an electric fixed‐bed gasifier to explore the cooperative gasification mechanisms of straw and kitchen waste. The effects of temperature, equivalence ratio as well as mixing ratio of straw and kitchen waste containing rice and trench oil on the gasification behaviors were investigated, combining the characterizations with SEM and FTIR. The results showed that the CH4 release volume fraction of single trench oil could up to 90%, as for the mixtures of straw, rice, and trench oil, the rapid reaction of oil could increase the gasification temperature, promote the bond fractures of CC and CH. Thereby those fractured matters could combine CO and H2 to generate CH4, which consequently improved the gas quality from straw gasification. As the equivalence ratio being 0.1 at 800°C, the actual calorific value of released gaseous from the mixture of straw, rice, and oil was at least 26% higher than the theoretical weighting value. When the mass ratio of straw, oil, and rice was 2:0.5:0.5, that superiority even reached 49.31%. Furthermore, in another fixed‐bed gasifier without external heating, the mixture of sun‐dried straw and actual kitchen waste containing much water could still achieve continuous gasification, and the experimental phenomena were similar to those above with the electric fixed‐bed gasifier. The real calorific value of the mixture of straw and kitchen waste was still higher than the theoretical weighting value. HIGHLIGHTS: Four main highlights of this manuscript are as follows: First, the cooperative gasification mechanisms of straw and kitchen waste were investigated with not only the electric heating reactor but also the self‐heating gasifier. Second, the cogasification could achieve much higher heat value than the weighting value from the single material gasification even without external heating. Third, the added kitchen waste increased the reaction temperature of gasification and promoted the breakage of function groups. Lastly, the mixture of preliminary dried straw and actual kitchen waste with more water could still achieve continuous gasification without external heating. [ABSTRACT FROM AUTHOR]

Albizia Chinensis is a plant easily found in Indonesia and other South East Asian countries. The sawdust from this plant is a lignocellulosic waste that can be potentially upgraded for the fuel purposes. This research investigated the potential of upgrading sawdust into a coal-like solid for fuel by a wet torrefaction process. In this project, a 1 L torrefaction reactor with an electric heater was employed to perform the carbonization of the Albizia chinensis sawdust. Wet torrefaction was performed in batch at temperatures of 190-230°C with holding times of 20oC, 30 and 60 min. The solid to water ratios of 1:3, 1:5 and 1:10 were used. The results showed that the chemical and physical properties of sawdust and hydrochar varied as a function of reaction temperature, holding time and solid load. The results also suggested that wet torrefaction could increase the fixed carbon in sawdust while the ash content and volatile matter decreased. The high heating value of hydrochar was 24.55 MJ/kg higher than raw sawdust, 18 MJ/kg. CO2 was predominantly detected in the gas phase, reaching the of >90% CO2. The liquid products were identified as sugar and organic acid compounds, which may be desirable feedstock for biochemical production. [ABSTRACT FROM AUTHOR]

Swine breeding generates liquid effluents contaminated by aggressive substances in the environment. The sector is associated with great effluent production that provides high loads of contaminants, strong colors and disagreeable smell. Effluent is characterized by water with high concentrations of organic carbon, nitrogen, phosphorus and fecal coliforms. These effluents are generally treated by conventional biological processes which are frequently inefficient. Current assay evaluates the efficiency of the electro-coagulation-flotation process (EFC) in the treatment of effluents generated by swine abattoirs to improve the system's operational parameters. For one year, samples were collected monthly at the entrance of the treatment station of abattoir effluents. Effluents underwent ECF lab assays with an electrochemical reactor coupled to aluminum electrode, with a variety of time exposure (0-60 min), current (1 - 5 A) and the reactor's electric capacity (0 - 24 V). Result show that the electrocoagulation-flotation process is efficient to remove contaminants in the crude effluent of the red line of swine abattoir. Mean efficiency in the removal of contaminants was significant. A mean 97% reduction in turbidity occurred; 94% in color; 89% in DQO; 90% in BOD; 88.5% in phosphorus; 88% in nitrogen; 58% in oils and fatty acids. [ABSTRACT FROM AUTHOR]

An auto-hydrogenotrophic bioelectrochemical system (BES) was set up to investigate the performance of removing nitrate (NO3−–N) and vanadate (V(V)) simultaneously. In this BES, hydrogen is produced during electrolytic reactions and the microorganisms on cathode biofilm can use it as the electron donor to reduce NO3−–N and V(V). This experiment confirmed that the removal efficiency of nitrate and vanadate could be improved by increasing the electric current and extending the hydraulic retention time (HRT) appropriately. The optimal electric current for the reactor was 200 mA with the optimum denitrification efficiency of 94.12%, vanadate removal efficiency of 77.55%. The optimal HRT was 12 h with the optimum denitrification efficiency of 94.40% and vanadate removal efficiency of 86.71%. However, by increasing the influent concentration of V(V), the removal efficiency of NO3−–N and V(V) were both reduced. These findings may help to reveal the biogeochemical fate of V(V) and nitrate in aquifers and develop technology that can simultaneously remove them from groundwater. [ABSTRACT FROM AUTHOR]

The influence of controlled phase shift between very high frequency (100 MHz) voltages applied to the powered electrodes on the plasma uniformity and etch rate was studied in a capacitive triode-type reactor. Radial profiles of plasma optical emission were measured as a function of the phase shift in process (C4F8/O2/Ar) plasma with the low frequency bias power both turned off and on. Radial profiles of KrF photoresist etch rate over a 300 mm wafer were obtained in the same conditions (with the bias power turned on). Besides, plasma density at the wafer center and edge was measured versus the phase shift in pure Ar plasma. It occurred that all measured characteristics strongly depend on the phase shift and correlate with each other. It has been shown that the phase-shift control can considerably improve both the plasma and etch-rate uniformity in very high-frequency capacitive reactors. [ABSTRACT FROM AUTHOR]

A theoretical equation has been derived in this paper for calculation of ozone generation by positive dc corona discharge in coaxial wire-cylinder reactors. The derived equation has been based on the theories of the positive dc coronas reported in the literature and extended to account the ozone destruction within the corona discharge plasma generated in the reactor. The equation has been investigated with experimental results for ozone generated in a coaxial wire-cylinder reactor under different discharge conditions. The reactor was stressed with a positive dc voltage and fed by dry air flowing with constant rates at atmospheric pressure and room temperature. The theoretical results calculated by the derived equation have shown good agreement with the experimental results over the whole range of the investigated parameters. Subsequently, the derived equation is valid to predict the ozone concentration generated in the investigated reactor under any discharge conditions. [ABSTRACT FROM AUTHOR]

This paper is aimed to investigating how the electrical power consumed in generating silent discharges is influenced by the width of the annular discharge gap in the reactor. The silent discharges have been generated in conventional tubular reactors forming annular discharge gaps of 1×10-3-, 2×10-3-, and 3×10-3-m width, with one dielectric barrier pasting on the ground electrodes of the reactors. The reactors were fed by dry air flowing with a constant rate at atmospheric pressure and room temperature, and stressed by an ac voltage. The discharge power consumed in generating silent discharges has been measured as a function of the voltage applied to the reactors up to a Vp of 20 000 V, and calculated by Manley’s equation under the same discharge conditions. The experimental and calculated results have shown that when the reactor has a discharge gap of 1×10-3- or 2×10-3-m width, Manley’s equation agrees only with the experimental results in range of the voltage of V0<=Vp<=Vc. In the higher range of the applied voltage of Vc<=Vp<=20 000 V, Manley’s equation has been modified to fit the experimental results. With the reactor that has a discharge gap of 3×10-3-m width, Manley’s equation agrees with the experimental results over the whole range of the voltage applied to the reactor. The results have been explained by recorded oscillograms showing the wave form of the ac voltage applied to the reactors and the corresponding discharge current. [ABSTRACT FROM AUTHOR]

It has previously been shown [Tuszewski et al., Plasma Sources Sci. Technol. 12, 396 (2003)] that inductive discharges in electronegative gases are subject to two types of instability: the source instability related to the E to H transition and a transport instability, occurring downstream when an expanding chamber is present. These two types of instability are observed in our “helicon” reactor operated without a static magnetic field in low-pressure Ar/SF6 mixtures. Temporally and spatially resolved measurements show that, in our experiment, the downstream instability is a periodic formation and propagation of a double layer. The double layer is born at the end of the source tube and propagates slowly to the end of the expansion region with a velocity of 150 m s-1. [ABSTRACT FROM AUTHOR]

A one-dimensional particle-in-cell/Monte Carlo model is used to investigate Ar/CF4/N2 discharges sustained in capacitively coupled dual frequency reactors, with special emphasis on the influence of the reactor parameters such as applied voltage amplitudes and frequencies of the two voltage sources. The presented calculation results include plasma density, ion current, average sheath potential and width, electron and ion average energies and energy distributions, and ionization rates. The simulations were carried out for high frequencies (HFs) of 27, 40, 60, and 100 MHz and a low frequency (LF) of 1 or 2 MHz, varying the LF voltage and keeping the HF voltage constant and vice versa. It is observed that the decoupling of the two sources is possible by increasing the applied HF to very high values (above 60 MHz) and it is not defined by the frequency ratio. Both voltage sources have influence on the plasma characteristics at a HF of 27 MHz and to some extent at 40 MHz. At HFs of 60 and 100 MHz, the plasma density and ion flux are determined only by the HF voltage source. The ion energy increases and the ion energy distribution function (IEDF) becomes broader with HF or LF voltage amplitude, when the other voltage is kept constant. The IEDF is broader with the increase of HF or the decrease of LF. [ABSTRACT FROM AUTHOR]

In large-area radio-frequency (rf) capacitive reactors, the redistribution of rf current to maintain current continuity near asymmetric sidewalls causes a perturbation in rf plasma potential to propagate along the resistive plasma between capacitive sheaths. The damping length of the perturbation can be determined by a telegraph equation. Experiments are described using a surface array of unbiased electrostatic probes in the ground electrode to verify the theoretical model of the telegraph effect in Howling et al. [J. Appl. Phys. 96, 5429 (2004)]. The measured spatial dependence of the plasma potential rf amplitude and circulating nonambipolar current agree well with two-dimensional numerical solutions of the telegraph equation. The rf plasma potential can be made uniform by using symmetric reactor sidewalls. [ABSTRACT FROM AUTHOR]

Presents a study on microcrystalline silicon thin-film transistors prepared by the layer-by-layer technique in a standard radio-frequency glow discharge reactor. Experiments; Results and discussion; Conclusions.

• Review of alternative methods to produce energy using poultry litter. • Use of an assignment model to allocate litter from poultry farms to electric reactors. • Solutions are obtained for single and multiple electric reactors. • Economic impact analysis show potential positive effects from building electric reactors. • An empirical model consists of real-world data from Louisiana, USA. Poultry litter has the potential to cause water quality problems if it is not applied properly to the land as a crop nutrient. Based on the data available from a survey of Louisiana poultry producers, we find that it is not cost effective to transport poultry litter farther than 38.6 km from the production facilities for crop nutrient purposes. This limited breakeven distance restricts the movement of poultry litter and points to a need to identify an alternative disposal method. We review common methods of producing electricity from poultry litter. We identify the minimum cost solution for assigning poultry litter when one large or three small electric reactors are chosen to be built for electricity production in the poultry production region. We calculate the cost-return analysis of building electric reactors and expand it to find the economic impact of starting such electric reactors to the local and regional economies. [ABSTRACT FROM AUTHOR]

Graphical abstract The best electrochemical reactor design decreased TCA to values below 1.5 ng/L in 85% of the cork discs. Highlights • Cork discs contaminated with TCA were subjected to electrochemical treatment. • Six reactor designs and four experimental variables were tested. • A low current density of 0.16 mA/cm2 was applied for 8 h in all experiments. • The EC technology removed TCA from the contaminated cork discs. • The best EC system decreased TCA to values below 1.5 ng/L in 85% of the cork discs. Abstract The electrochemical (EC) process for the removal of 2,4,6-trichloroanisole (TCA) from cork discs was investigated for the first time. For process development, six different EC reactors (based on a 3-compartment set-up) and four process variables were tested. Independently of the reactor design used, the application of a low level direct current for 8 h (10 mA, 0.16 mA/cm2) had a positive effect on TCA removal. The best option is to place the cork discs in a middle compartment separated from the cathode compartment by the use of a passive membrane, and from the anode compartment by a cation exchange membrane. In this reactor design, the TCA levels in 78% of the cork discs decreased to values below limit of detection (0.49 ng/L; TCA initial concentration between 0.5 and 2 ng/L). By immersing the discs' in a saline solution for 24 h prior current application, the TCA removal was improved by 10–15%. When the 34 cork discs contaminated with 2.5 times-fold more TCA were subjected to EC after 24 h immersion in the saline solution, the percentage of discs in which TCA concentration was below 0.49 ng/L decreased to 41%. Still, and considering that TCA perception threshold in wines starts at 1.5 ng/L, 85% of the cork discs exposed to EC reatment presented TCA levels below the threshold. Results showed that the here developed EC system could be a viable method for the removal of TCA from cork discs. [ABSTRACT FROM AUTHOR]

A three-dimensional (3D) finite-element analysis model is established based on the structural characteristics of ±1100 kV oblique-dry-type smoothing reactor, to optimisation of the external insulation configuration thereof by the Comsol Multiphysics. The electric field on the grading ring and insulators surface is calculated and analysed. The results show that the electric field is extremely uneven and the electric field strength of the outer layer of the rain cover and the grading ring connected with the lowest layer of the main body is the largest around the whole model. Accordingly, it is proposed to enlarge the diameter of the outer layer of the grading ring, reduce the layer numbers of grading ring on the rain cover, and reduce the smoothing layer numbers of grading ring outside the insulation pillar: this should make the electric field distribution of the reactor surface more uniform. The experimental platform was established in Beijing Changping ultra-high voltage test base and causalcomparative tests of setup were undertaken to compare the external insulation characteristics of the smoothing reactor optimised with the original. The experimental results demonstrate that the switching impulse voltage of the smoothing reactor increases and the external insulation performance of the smoothing reactor are thus improved. [ABSTRACT FROM AUTHOR]

Dense smoke from wildfires within a 500-kV line corridor led to several line protection trips over a three-day period. A switchable line-connected reactor, provided to control Ferranti voltages, tripped and locked out twice by its protection shortly after the line was de-energized. Lockout operation prevented quick reactor reinsertion and impeded operational flexibility until visual inspections of the reactor were conducted on both occasions. Forensic investigation of the event concluded that the smoke increased the line capacitances. This created a near 60-Hz zero sequence resonant circuit when the line tripped and became de-energized along with the reactor. The resonant circuit amplified the capacitively coupled zero sequence 60-Hz voltage induced from circuits which run adjacent to the line for a short distance. The voltage amplification drove enough current through the reactor to trip the sensitive ground overcurrent protection. A holistic mitigation is designed to avoid reoccurrence of the incident and improve overall line reliability. The intent of this paper is to share lessons learned from the event investigation with peer utilities because this problem of unexpected operation of line shunt reactor protection has not previously been reported. [ABSTRACT FROM AUTHOR]

When rectifier station of line-commutated converter based high-voltage direct transmission current has power fluctuations running at large load, reactive power compensator controlled in groups at rectifying station are switched frequently. That problem potentially has impact on service life of corresponding circuit breaker and threatens the safe operation of the DC system. In this study, in view of the characteristic of close connection between rectifier station and AC system, combined with the existing reactive power control scheme, in order to reduce the number of switching times of reactive power compensator, an optimal reactive power control scheme is proposed when rectifier station running at large load. When the converter station absorbs reactive power, the presented strategy takes converter bus voltage as the main control quantity with the starting point of taking full account of the reactive power support capacity of available generators near the station. When the converter station produces excess reactive power, the strategy takes the reactive power exchange of AC and DC system as the main control quantity, with the starting point of taking full account of reactive power absorption capacity of low-voltage reactor. The simulation results in power system analysis and synthesis program show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Adjustable reactor is an important VAR compensator for AC system, so it has practical significance to do researches on this device. This paper proposed a method of adjusting inductance value based on a controlled magnetic-wedge, which could change the air-gap in the magnetic path by adjusting the depth it inserted. The reactor based on this method was named as magnetic-wedge linear adjustable reactor. Its working principle and inductance's mathematical models were analysed in detail. ANSYS was used to simulate reactor's magnetic field in order to verify the analysis previously. A prototype was made and its inductance's adjustment curve was measured. Results showed that: the inductance's adjustment curve was a piecewise function. When the magnetic-wedge was in positive section, the relationship between inductance and depth of magnetic-wedge inserted was a linear function. If the magnetic-wedge was totally inserted, the air-gap was minimum while inductance was maximum. If the magnetic-wedge was totally pulled out, the air-gap was maximum while inductance was minimum. When the magnetic-wedge was in negative section, the relationship between inductance and magnetic-wedge's position was a double-exponential function, the nearer magnetic-wedge's position was, the more sensitively the inductance changed. Magnetic-wedge could control magnetic flux path and restrain air-gap edge effect. [ABSTRACT FROM AUTHOR]

Due to the influence of the external environment and the performance of measuring equipment, the on-line oil chromatography data contains obvious noise which makes the signal to oscillate. The monitoring data is difficult to be directly applied to the equipment state analysis. A novel wavelet-based de-noising method is proposed for pre-processing the on-line oil chromatography data. By analysing the characteristics of on-line oil chromatography data, the method of determining the decomposition layer number based on the probability distribution of wavelet coefficients and the method of determining the threshold value based on outliers conservation are proposed. The improved wavelet de-noising method is applied to analysing the on-line oil chromatography data of a defective ultra-high voltage (UHV) reactor. The results show that the proposed method is feasible and effective. [ABSTRACT FROM AUTHOR]

Highlights • EBIR for wastewater treatment containing ibuprofen were operated for 196 days. • Higher removal rates of ibuprofen, COD and NH 4 +-N were attained in EBIR than BAF. • Optimal conditions of EBIR were CD 12.73 A/m2, HRT 3.5 h and ibuprofen 0.08 mg/L. • Microbial community in EBIR and single BAF were analyzed at the optimal conditions. • EBIR is a highly efficient alternative technology to wastewater containing ibuprofen. Abstract Electric biological integration reactor (EBIR) was designed and built for the treatment of wastewater containing ibuprofen. This study evaluates the removal performance of EBIR by comparison with biological aerated filter (BAF), while also discussing the optimal operational parameters of EBIR within the context of the response surface methodology. The results indicate that EBIR exhibits higher average removal rates of ibuprofen, chemical oxygen demand (COD) and NH 4 +-N, i.e. 93.48%, 86.72% and 85.19%, representing an increase by 61.59%, 14.57% and 10.49%, respectively, compared with BAF. The optimal conditions for EBIR were 12.73 A/m2 current density (CD), 3.5 h hydraulic retention time and 0.08 mg/L influent ibuprofen concentration. In addition, microbial community structures were detected using an Illumina Miseq PE300 system, which were different at the phylum, class, and genus levels between EBIR and BAF. The microbial communities of EBIR, including mainly Trichococcus , Aeromonas , Saprospiraceae_uncultured , Thiobacillus , Aeromonas Flavobacterium , Sphingopyxis , Candidate_division_TM7_norank , Acinetobacter and physicochemical properties indirectly confirmed the excellent removal performance at 12.73 A/m2 CD. [ABSTRACT FROM AUTHOR]