scholarly journals Plasma-electrolyte discharges in a gas-liquid medium for the production of hydrogen

2021 ◽  
Vol 23 (2) ◽  
pp. 27-35
Author(s):  
A. F. Gaysin ◽  
F. M. Gaysin ◽  
L. N. Bagautdinova ◽  
A. A. Khafizov ◽  
R. I. Valiev ◽  
...  
Keyword(s):  
Liquid Medium ◽  
Electric Discharge ◽  
Discharge Current ◽  
Experimental Studies ◽  
Gaseous Hydrogen ◽  
Constant Current ◽  
Industrial Plant ◽  
Dielectric Tube ◽  
Discharge Ignition ◽  
Production Of Hydrogen

THE PURPOSE. Comprehensive study of the effect of direct current electric discharge plasma in a gas-liquid medium of inorganic mixtures in order to obtain gaseous hydrogen. Obtain volt-ampere, volt-second and ampere-second characteristics of the discharge at various concentrations of electrolyte. Study the process of electrolysis, breakdown, discharge ignition and discharge flow in a dielectric tube at a constant current. METHODS. To solve this problem, experimental studies were carried out on a model installation, which consists of a power supply system, a discharge chamber, equipment for monitoring and controlling the operation of the installation and measuring the characteristics of an electric discharge. To analyze the stability of the discharge, the time dependences of the voltage ripple and the discharge current were obtained. RESULTS. Experimental studies were carried out between the electrolytic cathode and the electrolytic anode at constant current and at atmospheric pressure with the following parameters: discharge voltage U = 0.1-1.5 kV, discharge current I = 0.02-2.3 A, interelectrode distance l = 100 mm , 1%, 3% and 5% solutions of sodium chloride in tap water were used as electrolytes. CONCLUSION. It is shown that electrical breakdown and ignition of a discharge that is stable in time depends on the conductivity of the gas-liquid medium of the electrolyte. The nature of the current-voltage characteristics depends on the random processes occurring in the gas-liquid medium, which is associated with numerous breakdowns occurring in the gas-liquid medium of the electrolyte, combustion and attenuation of microdischarges, the appearance of bubbles, and the movement of the electrolyte inside the dielectric tube. It is shown that the generation of hydrogen and hydrogen-containing components can occur both at the stage of electrolysis and during discharge combustion. A feature of this method is that electrical discharges in the tube increase the release of hydrogen. In this installation, inorganic and organic liquids of a certain composition and concentration can be used. The results of experimental studies made it possible to develop and create a small-sized installation for producing gaseous hydrogen. Tests have shown that a small-sized plant can be taken as the basis for a industrial plant for the production of hydrogen gas.

In-Plane Asymmetries on the Ge(111)-c(2×8) Surface Mapped with the Scanning Tunneling Microscope

1992 ◽  
Vol 295 ◽  
Author(s):  
P. Molinàs-Mata ◽  
J. Zegenhagen ◽  
M. Böhringer ◽  
N. Takeuchi ◽  
A. Selloni
Keyword(s):  
Local Density ◽  
Experimental Studies ◽  
Surface States ◽  
Small Sample ◽  
Constant Current ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Low Energy Electron ◽  
Tunneling Currents ◽  
Insight Into

AbstractWe report on new experimental studies of the Ge(111)-c(2×8) reconstruction performed with low-energy electron diffraction. (LEED) and scanning tunneling microscopy (STM). Weak quarter-order reflections are present in the c(2 × 8) LEED pattern in agreement with previous observations and results of ab initio calculations. In order to gain insight into the predicted splitting of dangling bond states, we compare constant current topographs (CCT's) performed at high-tunneling currents (40.nA) with first-principles calculations of the local density of states (LDOS) 1Å above the surface adatoms and obtain good qualitative agreement. We finally discuss to what extent the STM CCT's at high tunneling currents (small sample-tip distances (STD)) are sensitive to surface states outside the Г point.

scholarly journals Discharge performance and dynamic behavior of refuellable zinc-air battery

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Woranunt Lao-atiman ◽  
Sorin Olaru ◽  
Amornchai Arpornwichanop ◽  
Soorathep Kheawhom
Keyword(s):  
Dynamic Behavior ◽  
Discharge Current ◽  
Storage System ◽  
Cell Voltage ◽  
Energy Storage System ◽  
Constant Current ◽  
Discharge Data ◽  
Discharge Performance ◽  
Air Battery ◽  
Random Step

Abstract Zinc-air batteries (ZABs) are considered a promising energy storage system. A model-based analysis is one of the effective approaches for the study of ZABs. This technique, however, requires reliable discharge data as regards parameter estimation and model validation. This work, therefore, provides the data required for the modeling and simulation of ZABs. Each set of data includes working time, cell voltage, current, capacity, power, energy, and temperature. The data can be divided into three categories: discharge profiles at different constant currents, dynamic behavior at different step changes of discharge current, and dynamic behavior at different random step changes of discharge current. Constant current discharge profile data focus on the evolution of voltage through time. The data of step changes emphasize the dynamic behavior of voltage responding to the change of discharge current. Besides, the data of random step changes are similar to the data of step changes, but the patterns of step changes are random. Such data support the modeling of a zinc-air battery for both theoretical and empirical approaches.

Self-Pulsing Regime of DC Electric Discharge in Dielectric Tube Filled With Water Containing Gas Bubble

2008 ◽  
Vol 36 (4) ◽  
pp. 1142-1143 ◽  
Author(s):  
Yuri Akishev ◽  
Michail Grushin ◽  
Vlad Karalnik ◽  
Anton Monich ◽  
Alex Petryakov ◽  
...  
Keyword(s):  
Electric Discharge ◽  
Gas Bubble ◽  
Dielectric Tube

Fabrication of Efficient Electrodes for Dye-Sensitized Solar Cells Using Additive Manufacturing

2018 ◽  
Author(s):  
Sagil James ◽  
Rinkesh Contractor ◽  
Chris Veyna ◽  
Galen Jiang
Keyword(s):  
Solar Cells ◽  
Additive Manufacturing ◽  
Liquid Medium ◽  
Experimental Studies ◽  
Dye Sensitized Solar Cells ◽  
Light Condition ◽  
Small Scale ◽  
Dye Sensitized ◽  
Si Solar Cells ◽  
Sensitized Solar Cells

Dye-Sensitized Solar Cells (DSSC) are third generation solar cells used as an alternative to c-Si solar cells. DSSC are mostly flexible, easier to handle and are less susceptible to damage compared to c-Si solar cells. Additionally, DSSC is an excellent choice for indoor application as they perform better under diverse light condition. Most DSSCs are made of liquid medium sandwiched between two conductive polymer layers. However, DSSCs have significantly lower efficiencies compared to silicon solar cells. Also, use of liquid medium resulting in leaking of liquid, and occasional freezing during cold weather, and thermal expansion during hot weather conditions. DSSC can be manufactured in small quantities using relatively inexpensive solution-phase techniques such as roll-to-roll processing and screen printing technology. However, scaling-up the DSSC manufacturing from small-scale laboratory tests to sizeable industrial production requires better and efficient manufacturing processes. This research studies the feasibility of using additive manufacturing technique to fabricate electrodes of DSSC. The study aims to overcome the limitations of DSSCs including preventing leakage and providing more customized design. Experimental studies are performed to evaluate the effects of critical process parameters affecting the quality of electrodes for DSSC. Volume resistivity test is performed to evaluate the efficiency of the electrodes. In this study, the electrodes of DSSC are successfully fabricated using Fused Disposition Modeling (FDM) 3D printing technique. The results of this study would enable additive manufacturing technology towards rapid commercialization of DSSC technology.

Experimental Study of the Dry and Near-Dry Electrical Discharge Milling Processes

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Jia Tao ◽  
Albert J. Shih ◽  
Jun Ni
Keyword(s):  
Pulse Duration ◽  
Surface Finish ◽  
Discharge Current ◽  
Electrical Discharge ◽  
Experimental Studies ◽  
Fractional Factorial ◽  
Pulse Interval ◽  
Water Mixture ◽  
Dry Edm ◽  
Fine Surface

This study investigates the dry and near-dry electrical discharge machining (EDM) milling to achieve a high material removal rate (MRR) and fine surface finish for roughing and finishing operations, respectively. Dry EDM uses gas and near-dry EDM applies a liquid-gas mixture as the dielectric medium. Experimental studies leading to the selection of oxygen gas and copper electrode for high MRR dry EDM and the nitrogen-water mixture and graphite electrode for fine surface finish near-dry EDM are presented. Near-dry EDM exhibits the advantage of good machining stability and surface finish under low discharge energy input. A 25−1 fractional factorial design is applied to investigate the effect of discharge current, pulse duration, and pulse interval on the MRR and surface finish in dry and near-dry EDMs. Lower pulse duration and lower discharge current are identified as key factors for improving the surface finish in near-dry EDM.

scholarly journals Hole size effect on microhollow cathode discharge in air

2021 ◽  
Vol 2064 (1) ◽  
pp. 012032
Author(s):  
S I Moshkunov ◽  
S V Nebogatkin ◽  
K I Romanov ◽  
E A Shershunova
Keyword(s):  
Discharge Current ◽  
Hole Diameter ◽  
Hole Size ◽  
Electrical Parameters ◽  
Atmospheric Air ◽  
Ignition Voltage ◽  
Microhollow Cathode Discharge ◽  
Discharge Ignition ◽  
Discharge Ignition Voltage ◽  
Microhollow Cathode

Abstract In this work the values of main electrical parameters of the microhollow cathode discharge in atmospheric air (peak discharge current, discharge ignition voltage) depending on the diameter of the hole in the cathode were obtained. It was experimentally found that at currents up to 2 mA, the discharge operated in a self-pulsing mode. According to the experimental results it was concluded that the value of the discharge ignition voltage at average discharge current exceeding 2 mA didn’t depend on the hole diameter.

scholarly journals Removal of ethylene oxide from waste gases by absorption

2011 ◽  
Vol 65 (4) ◽  
pp. 389-395 ◽  
Author(s):  
Zorana Arsenijevic ◽  
Zeljko Grbavcic ◽  
Bosko Grbic ◽  
Nenad Radic ◽  
Radmila Garic-Grulovic ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Contact Time ◽  
Organic Pollutant ◽  
Experimental Studies ◽  
Industrial Plant ◽  
Emission Sources ◽  
Crucial Importance ◽  
In Series ◽  
Time Part ◽  
High Degree

Ethylene oxide (EtO) is an organic compound, which is used as starting material in the production of polymers and as sterilizing agent for thermolabile materials. Although ethylene oxide is not common as an organic pollutant, its removal from numerous emission sources (e.g. ethylene oxide production plants or food and pharmaceutical sterilizing units) is of the crucial importance because of its mutagenic, teratogenic and cancerogenic effect on human health. The objective of this paper is the experimental investigation of ethylene oxide (EtO) absorption in diluted aqueous solution of sulfuric acid in order to evaluate the applicability of this procedure as well as to obtain project parameters for industrial plant realization. It was found that absorption is suitable as the fist step in the purification treatment of high EtO concentrations in the emission gases. According to the literature data, the basic parameter that defines the scrubber efficiency is the contact time, i.e. the ratio of packing height in scrubber and velocity of gas mixture. To investigate the characteristics of wet treatment in a broad range of contact time, part of experimental studies were conducted in the system with two and with three scrubbers in series. The obtained experimental results show that the high degree of EtO removal can be achieved (>98%) when the contact time is sufficiently long (about 25 s). The process is effective until the concentration of formed glycol in the solution reaches value of about 20%. The process is safe and there is no danger of ignition and explosion of air and EtO mixture, although at the entrance to the scrubber EtO concentrations are significantly above the lower explosive limit.

scholarly journals Recent Achievements in Microalgal Photobiological Hydrogen Production

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7170
Author(s):  
Eleftherios Touloupakis ◽  
Cecilia Faraloni ◽  
Ana Margarita Silva Benavides ◽  
Giuseppe Torzillo
Keyword(s):  
Public Opinion ◽  
Hydrogen Production ◽  
Photosystem Ii ◽  
Chlamydomonas Reinhardtii ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Energy Transition ◽  
Gaseous Hydrogen ◽  
Fossil Energy ◽  
Production Of Hydrogen

It is well known that over the last 60 years the trend of long-lived greenhouse gas emissions have shown a strong acceleration. There is an increasing concern and a mounting opposition by public opinion to continue with the use of fossil energy. Western countries are presently involved in a so-called energy transition with the objective of abandoning fossil energy for renewable sources. In this connection, hydrogen can play a central role. One of the sustainable ways to produce hydrogen is the use of microalgae which possess two important natural catalysts: photosystem II and hydrogenase, used to split water and to combine protons and electrons to generate gaseous hydrogen, respectively. For about 20 years of study on photobiological hydrogen production, our scientific hopes were based on the application of the sulfur protocol, which indisputably represented a very important advancement in the field of hydrogen production biotechnology. However, as reported in this review, there is increasing evidence that this strategy is not economically viable. Therefore, a change of paradigm for the photobiological production of hydrogen based on microalgae seems mandatory. This review points out that an increasing number of microalgal strains other than Chlamydomonas reinhardtii are being tested and are able to produce sustainable amount of hydrogen without nutrient starvation and to fulfill this goal including the application of co-cultures.

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