Search results for: electrolysis

Authors: Inom Sh. Normatov, Nurmakhmad Shermatov, Rajabali Barotov, Rano Eshankulova

Abstract:

The results of the studies for the hydrogen production by the application of water electrolysis and plasma-chemical processing of gas condensate-waste of natural gas production methods are presented. Thin coating covers the electrode surfaces in the process of water electrolysis. Therefore, water for electrolysis was first exposed to electrosedimentation. The threshold voltage is shifted to a lower value compared with the use of electrodes made of stainless steel. At electrolysis of electrosedimented water by use of electrodes from stainless steel, a significant amount of hydrogen is formed. Pyrolysis of gas condensates in the atmosphere of a nitrogen was followed by the formation of acetylene (3-7 vol.%), ethylene (4-8 vol.%), and pyrolysis carbon (10-15 wt.%).

Keywords: electrolyze, gascondensate, hydrogen, pyrolysis

Procedia PDF Downloads 316

Authors: Julian David Hunt, Andreas Nascimento

Abstract:

Green hydrogen is the most environmental, renewable alternative to produce hydrogen. However, an important challenge to make hydrogen a competitive energy carrier is a constant supply of renewable energy, such as solar, wind and hydropower. Given that the electricity generation potential of these sources vary seasonally and interannually, this paper proposes installing an electrolysis hydrogen production plant in a ship and move the ship to the locations where electricity is cheap, or where the seasonal potential for renewable generation is high. An example of electrolysis ship application is to produce green hydrogen with hydropower from the North region of Brazil and then sail to the Northeast region of Brazil and generate hydrogen using excess electricity from offshore wind power. The electrolysis ship concept is interesting because it has the flexibility to produce green hydrogen using the cheapest renewable electricity available in the market.

Keywords: green hydrogen, electrolysis ship, renewable energies, seasonal variations

Procedia PDF Downloads 171

Authors: Jeong-Hyun Yoo, Hanjung Kwon, Sung-Wook Cho

Abstract:

Fused salt electrolysis was studied to make the high purity rare-earth metals using domestic rare-earth ore. The target metals of the fused salt electrolysis were Mm (Misch metal), La, Ce, Nd, etc. Fused salt electrolysis was performed with the supporting salt such as chloride and fluoride at the various temperatures and ampere. The metals made by fused salt electrolysis were analyzed to identify the phase and composition using the methods of XRD and ICP. As a result, the acquired rare-earth metals were the high purity ones which had more than 99% purity. Also, VIM (vacuum induction melting) was studied to make the kg level rare-earth alloy for the use of secondary battery and hydrogen storage. In order to indentify the physicochemical properties such as phase, impurity gas, alloy composition and hydrogen storage, the alloys were investigated. The battery characteristics were also analyzed through the various tests in the real production line of a battery company.

Keywords: domestic rare-earth ore, fused salt electrolysis, rare-earth materials, hydrogen storage alloy, secondary battery

Procedia PDF Downloads 545

Authors: I. M. Sakr, Ali M. Abdelsalam, K. A. Ibrahim, W. A. El-Askary

Abstract:

This paper presents an experimental study for hydrogen production using alkaline water electrolysis operated by solar energy. Two methods are used and compared for separation between the cathode and anode, which are acrylic separator and polymeric membrane. Further, the effects of electrolyte concentration, solar insolation, and space between the pair of electrodes on the amount of hydrogen produced and consequently on the overall electrolysis efficiency are investigated. It is found that the rate of hydrogen production increases using the polymeric membrane installed between the electrodes. The experimental results show also that, the performance of alkaline water electrolysis unit is dominated by the electrolyte concentration and the gap between the electrodes. Smaller gaps between the pair of electrodes are demonstrated to produce higher rates of hydrogen with higher system efficiency.

Keywords: hydrogen production, water electrolysis, solar energy, concentration

Procedia PDF Downloads 385

Authors: Ligang Wang, Theodoros Damartzis, Stefan Diethelm, Jan Van Herle, François Marechal

Abstract:

Biogas production from anaerobic digestion of organic sludge from wastewater treatment as well as various urban and agricultural organic wastes is of great significance to achieve a sustainable society. Two upgrading approaches for cleaned biogas can be considered: (1) direct H₂ injection for catalytic CO₂ methanation and (2) CO₂ separation from biogas. The first approach usually employs electrolysis technologies to generate hydrogen and increases the biogas production rate; while the second one usually applies commercially-available highly-selective membrane technologies to efficiently extract CO₂ from the biogas with the latter being then sent afterward for compression and storage for further use. A straightforward way of utilizing the captured CO₂ is on-site catalytic CO₂ methanation. From the perspective of system complexity, the second approach may be questioned, since it introduces an additional expensive membrane component for producing the same amount of methane. However, given the circumstance that the sustainability of the produced biogas should be retained after biogas upgrading, renewable electricity should be supplied to drive the electrolyzer. Therefore, considering the intermittent nature and seasonal variation of renewable electricity supply, the second approach offers high operational flexibility. This indicates that these two approaches should be compared based on the availability and scale of the local renewable power supply and not only the technical systems themselves. Solid-oxide electrolysis generally offers high overall system efficiency, and more importantly, it can achieve simultaneous electrolysis of CO₂ and H₂O (namely, co-electrolysis), which may bring significant benefits for the case of CO₂ separation from the produced biogas. When taking co-electrolysis into account, two additional upgrading approaches can be proposed: (1) direct steam injection into the biogas with the mixture going through the SOE, and (2) CO₂ separation from biogas which can be used later for co-electrolysis. The case study of integrating SOE to a wastewater treatment plant is investigated with wind power as the renewable power. The dynamic production of biogas is provided on an hourly basis with the corresponding oxygen and heating requirements. All four approaches mentioned above are investigated and compared thermo-economically: (a) steam-electrolysis with grid power, as the base case for steam electrolysis, (b) CO₂ separation and co-electrolysis with grid power, as the base case for co-electrolysis, (c) steam-electrolysis and CO₂ separation (and storage) with wind power, and (d) co-electrolysis and CO₂ separation (and storage) with wind power. The influence of the scale of wind power supply is investigated by a sensitivity analysis. The results derived provide general understanding on the economic competitiveness of SOE for sustainable biogas upgrading, thus assisting the decision making for biogas production sites. The research leading to the presented work is funded by European Union’s Horizon 2020 under grant agreements n° 699892 (ECo, topic H2020-JTI-FCH-2015-1) and SCCER BIOSWEET.

Keywords: biogas upgrading, solid-oxide electrolyzer, co-electrolysis, CO₂ utilization, energy storage

Procedia PDF Downloads 164

Authors: Tam D. Nguyen, Joe Varga, Douglas MacFarlane, Alexandr Simonov

Abstract:

Development of advanced technologies for green hydrogen generation from renewables is of key strategic importance to global future energy security and economic growth. Renewable-powered water electrolysis (WE) is considered as the most effective of the sustainable methods for hydrogen generation at scale. Currently, the greatest challenge of hydrogen production via water electrolysis is the insufficiently high efficiency. In which, the energy loss associated with the conversion of water to hydrogen is approximately 40-60%, with 30-35% associated with the electrolysis itself and 10-12% with gas compression and transportation. Hence, development of an energy-efficient water electrolyser that can generate hydrogen at high pressure will address both of these major challenges. This requires the development of advanced electrode configuration of the water electrolysis cell. Herein, we developed a highly-ordered interconnected structure of the metallic inverse-opal (IO) frameworks based on low cost materials, e.g. Cu, Ni, Fe, Co. The water electrolysis electrodes based on these frameworks can provide excellent mechanical strength required for the application under conditions of extreme pressure, as well as outstanding catalytic performance through the exceptional high surface area and high electrical conductivity. For example, NiFe layered double hydroxide (LDH) catalyst deposited on Cu IO is able to reach the oxygen evolution reaction (OER) catalytic performance up to the rates of > 100 mA cm−2 (>727A gcatalyst-1) at an overpotential of ~0.3 V. This high performance is achieved with only few micron-thick catalyst layers, in contrast to similarly performance of 103-fold thicker electrodes based on foams and other substrates.

Keywords: oxygen evolution reaction, support materials, mass transport, NiFe LDH

Procedia PDF Downloads 24

Authors: Ekki Kurniawan, Yusuf Nur Jayanto, Erna Sugesti, Efri Suhartono, Agus Ganda Permana, Jaspar Hasudungan, Jangkung Raharjo, Rintis Manfaati

Abstract:

The purpose of this research is to study the current characteristic of the electrolysis of mineral water to produce hydrogen, alkaline water, and acid water. Alkaline and hydrogen water are believed to have health benefits. Alkaline water containing hydrogen can be an anti-oxidant that captures free radicals, which will increase the immune system. In Indonesia, there are two existing types of alkaline water producing equipment, but the installation is complicated, and the price is relatively expensive. The electrolysis process is slow (6-8 hours) since they are locally made using 311 VDC full bridge rectifier power supply. This paper intends to discuss how to make hydrogen and alkaline water by a simple portable mineral water ionizer. This is an electrolysis device that is easy to carry and able to separate ions of mineral water into acidic and alkaline water. With an electric field, positive ions will be attracted to the cathode, while negative ions will be attracted to the anode. The circuit equivalent can be depicted as RLC transient ciruit. The diode component ensures that the electrolytic current is direct current. Switch S divides the switching times t1, t2, and t3. In the first stage up to t1, the electrolytic current increases exponentially, as does the inductor charging current (L). The molecules in drinking water experience magnetic properties. The direction of the dipole ions, which are random in origin, will regularly flare with the direction of the electric field. In the second stage up to t2, the electrolytic current decreases exponentially, just like the charging current of a capacitor (C). In the 3rd stage, start t3 until it tends to be constant, as is the case with the current flowing through the resistor (R).

Keywords: current electrolysis, mineral water, ions, alkaline and acid waters, inductor, capacitor, resistor

Procedia PDF Downloads 126

Authors: Ewa Brychcy, Natalia Ulbin-Figlewicz, Dominika Kulig, Żaneta Król, Andrzej Jarmoluk

Abstract:

Acidic electrolyzed water (AEW) is an alternative with environmentally friendly broad spectrum microbial decontamination. It is produced by membrane electrolysis of a dilute NaCl solution in water ionizers. The aim of the study was to evaluate the effectiveness of low-concentrated AEW in reducing selected foodborne pathogens and to examine its bactericidal effect on cellular structures of Escherichia coli. E. coli and S. aureus cells were undetectable after 10 minutes of contact with electrolyzed salt solutions. Non-electrolyzed solutions did not inhibit the growth of bacteria. AE water was found to destroy the cellular structures of the E. coli. The use of more concentrated salt solutions and prolonged electrolysis time from 5 to 10 minutes resulted in a greater changes of rods shape as compared to the control and non-electrolyzed NaCl solutions. This research showed that low-concentrated acid electrolyzed water is an effective method to significantly reduce pathogenic microorganisms and indicated its potential application for decontamination of meat.

Keywords: acidic electrolyzed water, foodborne pathogens, meat decontamination, membrane electrolysis

Procedia PDF Downloads 505

Authors: Mustafa A. Al-Refai

Abstract:

This paper investigates the energy storage technologies that can potentially enhance the use of solar energy. Water electrolysis systems are seen as the principal means of producing a large amount of hydrogen in the future. Starting from the analysis of the models of the system components, a complete simulation model was realized in the Matlab-Simulink environment. Results of the numerical simulations are provided. The operation of electrolysis and photovoltaic array combination is verified at various insulation levels. It is pointed out that solar cell arrays and electrolysers are producing the expected results with solar energy inputs that are continuously varying.

Keywords: electrolyzer, simulink, solar energy, storage system

Procedia PDF Downloads 444

Authors: Astari Indarsari, Bastian B. Purba, Muhammad Fadlilah

Abstract:

In Indonesian climates that have the tropic climate, one of the potential energy sources is coming from solar energy. From the solar energy, we can convert it into the others energy, such as electrical energy. In this topic, we want to do the research about Dye Sensitized Solar Cell (DSSC). The materials that we use as sensitizer is anthocyanin that we extract from apple skin, because the anthocyanin is one of the most effective as a sensitizer for DSSC. The variable in this research is pH. The pH that we used are pH 0,5; pH 1; pH 1,5; pH 2; pH 2,5. The method is electrolysis, and we use TiO2 as sensitized material. The hypothesis from this research is the smaller pH can make higher the efficiency of the absorbent of the solar energy.

Keywords: anthocyanin, TiO2, DSSC, apple skin

Procedia PDF Downloads 302

Authors: Pujari Muruga, T. K. Radhakrishnan, N. Samsudeen

Abstract:

Hydrogen is considered as the most important energy carrier and fuel of the future because of its high energy density and zero emission properties. Microbial Electrolysis Cell (MEC) is a new and promising approach for hydrogen production from organic matter, including wastewater and other renewable resources. By utilizing anode microorganism activity, MEC can produce hydrogen gas with smaller voltages (as low as 0.2 V) than those required for electrolytic hydrogen production ( ≥ 1.23 V). The hydrogen production processes of the MEC reactor are very nonlinear and highly complex because of the presence of microbial interactions and highly complex phenomena in the system. Increasing the hydrogen production rate and lowering the energy input are two important challenges of MEC technology. The mathematical model of the MEC is based on material balance with the integration of bioelectrochemical reactions. The main objective of the research is to produce biohydrogen by selecting the optimum current and controlling applied voltage to the MEC. Precise control is required for the MEC reactor, so that the amount of current required to produce hydrogen gas can be controlled according to the composition of the substrate in the reactor. Various simulation tests involving multiple set-point changes disturbance and noise rejection were performed to evaluate the performance using PID controller tuned with Ziegler Nichols settings. Simulation results shows that other good controller can provide better control effect on the MEC system, so that higher hydrogen production can be obtained.

Keywords: microbial electrolysis cell, hydrogen production, applied voltage, PID controller

Procedia PDF Downloads 255

Authors: Fahad Alamoudi, Yaser Miaji

Abstract:

The growing popularity of swimming pools and other activities in the water for sport, fitness, therapy or just enjoyable relaxation have led to the increased use of swimming pools and the establishment of a variety of specific-use pools such as spa pools, water slides, and more recently, hydrotherapy and wave pools. In this research, a few simple equipment is used for test, detect and alert for detection of water cleanness and pollution. YSI Photometer Systems, TDSTestr High model, Rio 12HF and Electrode A1. The researchers used electrolysis as a method of separating bonded elements and compounds by passing an electric current through them. The results which use 41 experiments show the higher the salt concentration, the more efficient the electrode and the smaller the gap between the plates, the lower the electrode voltage. Furthermore, it is proved that the larger the surface area, the lower the cell voltage and the higher current used the more chlorine produced.

Keywords: photometer, electrode, electrolysis, swimming pool chlorination

Procedia PDF Downloads 370

Authors: Fahad Alamoudi, Yaser Miaji, Fawzy Jalalah

Abstract:

The growing popularity of swimming pools and other activities in the water for sport, fitness, therapy or just enjoyable relaxation have led to the increased use of swimming pools and the establishment of a variety of specific-use pools such as spa pools, Waterslides and more recently, hydrotherapy and wave pools. In this research a few simple equipments are used for test, Detect and alert for detection of water cleanness and pollution. YSI Photometer Systems, TDSTestr High model, rio 12HF, and Electrode A1. The researchers used electrolysis as a method of separating bonded elements and compounds by passing an electric current through them. The results which use 41 experiments show the higher the salt concentration, the more efficient the electrode and the smaller the gap between the plates and The lower the electrode voltage. Furthermore, it is proved that the larger the surface area, the lower the cell voltage and the higher current used the more chlorine produced.

Keywords: photometer, electrode, electrolysis, swimming pool chlorination

Procedia PDF Downloads 361

Authors: Wei Zha, Jingzeng Zhang, Chen Zhao, Ran Cai, Xueyuan Nie

Abstract:

Cathodic plasma electrolysis (CPE) is used to create surface textures on cast iron samples for improving the tribological properties. Micro craters with confined size distribution were successfully formed by CPE process. These craters can generate extra hydrodynamic pressure that separates two sliding surfaces, increase the oil film thickness and accelerate the transition from boundary to mixed lubrication. It was found that the optimal crater size was 1.7 μm, at which the maximum lubrication efficiency was achieved. The Taguchi method was used to optimize the process parameters (voltage and roughness) for CPE surface texturing. The orthogonal array and the signal-to-noise ratio were employed to study the effect of each process parameter on the coefficient of friction. The results showed that with higher voltage and lower roughness, the lower friction coefficient can be obtained, and thus the lubrication can be more efficiently used for friction reduction.

Keywords: cathodic plasma electrolysis, friction, lubrication, plasma surface texturing

Procedia PDF Downloads 144

Authors: Franky Michael Hamonangan Siagian, Affan Maulana, Himawan Tri Bayu Murti Petrus, Widi Astuti

Abstract:

In this study, the feasibility of the direct electrowinning method was used to produce zero-valent iron from red mud. The bauxite residue sample came from the Tayan mine, Indonesia, which contains high hematite (Fe₂O₃). Before electrolysis, the samples were characterized by various analytical techniques (ICP-AES, SEM, XRD) to determine their chemical composition and mineralogy. The direct electrowinning method of red mud suspended in NaOH was introduced at low temperatures ranging from 30 - 110 °C. Variations of current density, red mud: NaOH ratio and temperature were carried out to determine the optimum operation of the direct electrowinning process. Cathode deposits and residues in electrochemical cells were analyzed using XRD, XRF, and SEM to determine the chemical composition and current recovery. The low-temperature electrolysis current efficiency on Redmud can reach 20% recovery at a current density of 920,945 A/m². The moderate performance of the process was investigated with red mud, which was attributed to the troublesome adsorption of red mud particles on the cathode, making the reduction far less efficient than that with hematite.

Keywords: red mud, electrochemical reduction, Iron production, hematite

Procedia PDF Downloads 82

Authors: Franky Michael Hamonangan Siagian, Affan Maulana, Himawan Tri Bayu Murti Petrus, Panut Mulyono, Widi Astuti

Abstract:

In this study, the feasibility of the direct electrowinning method was used to produce zero-valent iron from red mud. The bauxite residue sample came from the Tayan mine, Indonesia, which contains high hematite (Fe₂O₃). Before electrolysis, the samples were characterized by various analytical techniques (ICP-AES, SEM, XRD) to determine their chemical composition and mineralogy. The direct electrowinning method of red mud suspended in NaOH was introduced at low temperatures ranging from 30 - 110 °C. Variations of current density, red mud: NaOH ratio and temperature were carried out to determine the optimum operation of the direct electrowinning process. Cathode deposits and residues in electrochemical cells were analyzed using XRD, XRF, and SEM to determine the chemical composition and current recovery. The low-temperature electrolysis current efficiency on Redmud can reach 20% recovery at a current density of 920,945 A/m². The moderate performance of the process was investigated with red mud, which was attributed to the troublesome adsorption of red mud particles on the cathode, making the reduction far less efficient than that with hematite.

Keywords: alumina, red mud, electrochemical reduction, iron production

Procedia PDF Downloads 89

Authors: Boldin Roman, Liliana Analía Diaz

Abstract:

As the hydrogen economy continues to expand, reducing energy consumption and emissions while stimulating economic growth, the development of efficient and cost-effective hydrogen production technologies is critical. Among various methods, anion exchange membrane (AEM) water electrolysis stands out due to its potential for using non-noble metal catalysts. The exploration and enhancement of non-noble metal catalysts, such as NiFe-type catalysts, are pivotal for the advancement of AEM technology, ensuring its commercial viability and environmental sustainability. NiFe-type catalysts were synthesized through electrodeposition and characterized both electrochemically and physico-chemically. Various supports, including Ni foam and Ni mesh, were used as porous transport layers (PTLs) to evaluate the effective catalyst thickness and the influence of the PTL in a 5 cm² AEM electrolyzer. This methodological approach allows for a detailed assessment of catalyst performance under operational conditions typical of industrial hydrogen production. The study revealed that electrodeposited non-noble multi-metallic catalysts maintain stable performance as anodes in AEM water electrolysis. NiFe-type catalysts demonstrated superior activity, with the NiFeCoP alloy outperforming others by delivering the lowest overpotential and the highest current density. Furthermore, the use of different PTLs showed significant effects on the electrochemical behavior of the catalysts, indicating that PTL selection is crucial for optimizing performance and efficiency in AEM electrolyzers. Conclusion: The research underscores the potential of non-noble metal catalysts in enhancing efficiency and reducing the costs of AEM electrolysers. The findings highlight the importance of catalyst and PTL optimization in developing scalable and economically viable hydrogen production technologies. Continued innovation in this area is essential for supporting the growth of the hydrogen economy and achieving sustainable energy solutions.

Keywords: AEMWE, electrocatalyst, hydrogen production, water electrolysis.

Procedia PDF Downloads 43

Authors: Peerawat Khongkliang, Prawit Kongjan, Tsuyoshi Imai, Poonsuk Prasertsan, Sompong O-Thong

Abstract:

A two-stage thermophilic fermentation and electrohydrogenesis process was used to convert cassava starch processing wastewater into hydrogen gas. Maximum hydrogen yield from fermentation stage by Thermoanaerobacterium thermosaccharolyticum PSU-2 was 248 mL H2/g-COD at optimal pH of 6.5. Optimum hydrogen production rate of 820 mL/L/d and yield of 200 mL/g COD was obtained at HRT of 2 days in fermentation stage. Cassava starch processing wastewater fermentation effluent consisted of acetic acid, butyric acid and propionic acid. The effluent from fermentation stage was used as feedstock to generate hydrogen production by microbial electrolysis cell (MECs) at an applied voltage of 0.6 V in second stage with additional 657 mL H2/g-COD was produced. Energy efficiencies based on electricity needed for the MEC were 330 % with COD removals of 95 %. The overall hydrogen yield was 800-900 mL H2/g-COD. Microbial community analysis of electrohydrogenesis by DGGE shows that exoelectrogens belong to Acidiphilium sp., Geobacter sulfurreducens and Thermincola sp. were dominated at anode. These results show two-stage thermophilic fermentation, and electrohydrogenesis process improved hydrogen production performance with high hydrogen yields, high gas production rates and high COD removal efficiency.

Keywords: cassava starch processing wastewater, biohydrogen, thermophilic fermentation, microbial electrolysis cell

Procedia PDF Downloads 351

Authors: Christian C. Vaso, Rinlee Butch M. Cervera

Abstract:

One of the most promising anode materials for solid oxide electrolysis cell (SOEC) application is the Sr-doped LaMnO₃ (LSM) which is known to have a high electronic conductivity but low ionic conductivity. To increase the ionic conductivity or diffusion of ions through the anode, Yttria-stabilized Zirconia (YSZ), which has good ionic conductivity, is proposed to be combined with LSM to create a composite electrode and to obtain a high mixed ionic and electronic conducting anode. In this study, composite of lanthanum strontium manganite and YSZ oxide, La_0.8Sr_0.2MnO₃/Zr_0.92Y_0.08O₂ (LSM/YSZ), with different wt.% compositions of LSM and YSZ were synthesized using solid-state reaction. The obtained prepared composite samples of 60, 50, and 40 wt.% LSM with remaining wt.% of 40, 50, and 60, respectively for YSZ were fully characterized for its microstructure by using powder X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and Scanning electron microscope/Energy dispersive spectroscopy (SEM/EDS) analyses. Surface morphology of the samples via SEM analysis revealed a well-sintered and densified pure LSM, while a more porous composite sample of LSM/YSZ was obtained. Electrochemical impedance measurements at intermediate temperature range (500-700 °C) of the synthesized samples were also performed which revealed that the 50 wt.% LSM with 50 wt.% YSZ (L50Y50) sample showed the highest total conductivity of 8.27x10^-1 S/cm at 600 ^oC with 0.22 eV activation energy.

Keywords: ceramics, microstructure, fuel cells, electrochemical impedance spectroscopy

Procedia PDF Downloads 256

Authors: Ewa Rudnik

Abstract:

Poster shows a comparison of hydrometallurgical routes of copper recovery from low-grade e-waste. Electronic scrap was smelted to produce Cu–Zn–Ag alloy. The alloy was then treated in the following ways: (a) anodic dissolution with simultaneous metal electrodeposition using ammoniacal and sulfuric acid solutions. This resulted in the separation of metals, where lead, silver and tin accumulated mainly in the slimes, while copper was transferred to the electrolyte and then recovered on the cathode. The best conditions of the alloy treatment were obtained in the sulfuric acid, where the final product was metal of high purity (99% Cu) at the current efficiency of 90%. (b) leaching in ammoniacal solutions of various compositions and then copper electrowinning. Alloy was leached in chloride, carbonate, sulfate and thiosulfate baths. This resulted in the separation of the metals, wherein copper and zinc were transferred to the electrolyte, while metallic tin and silver as well as lead salts remained in the slimes. Copper was selectively recovered from the ammoniacal solutions by the electrolysis, leaving zinc ions in the electrolyte. The best conditions of the alloy treatment were obtained in the ammonia-carbonate system, where the final product was copper of high purity (99.9%) at the current efficiency of 60%. Thiosulfate solution was not applicable for the leaching of the copper alloy due to secondary reactions of the formation of copper (I) thiosulfate complexes and precipitation of copper (I) sulfide.

Keywords: alloy, electrolysis, e-waste, leaching

Procedia PDF Downloads 378

Authors: Sourour Chaabane, Davide Clematis, Marco Panizza

Abstract:

This study investigates the oxidation of Erythrosine B (EB) food dye by a homogeneous electro-Fenton process using iron (II) sulfate heptahydrate as a catalyst, carbon felt as cathode, and Ti/RuO2. The treated synthetic wastewater contains 100 mg L⁻¹ of EB and has a pH = 3. The effects of three independent variables have been considered for process optimization, such as applied current intensity (0.1 – 0.5 A), iron concentration (1 – 10 mM), and stirring rate (100 – 1000 rpm). Their interactions were investigated considering response surface methodology (RSM) based on Doehlert design as optimization method. EB removal efficiency and energy consumption were considered model responses after 30 minutes of electrolysis. Analysis of variance (ANOVA) revealed that the quadratic model was adequately fitted to the experimental data with R² (0.9819), adj-R² (0.9276) and low Fisher probability (< 0.0181) for EB removal model, and R² (0.9968), adj-R² (0.9872) and low Fisher probability (< 0.0014) relative to the energy consumption model reflected a robust statistical significance. The energy consumption model significantly depends on current density, as expected. The foregoing results obtained by RSM led to the following optimal conditions for EB degradation: current intensity of 0.2 A, iron concentration of 9.397 mM, and stirring rate of 500 rpm, which gave a maximum decolorization rate of 98.15 % with a minimum energy consumption of 0.74 kWh m⁻³ at 30 min of electrolysis.

Keywords: electrofenton, erythrosineb, dye, response serface methdology, carbon felt

Procedia PDF Downloads 82

Authors: Seval Yilmaz, Filiz Bayrakci Karel, Ali Savas Koparal

Abstract:

Textile products produced by leather have been indispensable for human consumption. Various chemicals are used to enhance the durability of end-products in the processing of leather products. The wastewaters from the leather industry which contain these chemicals exhibit toxic effects on the receiving environment and threaten the natural ecosystem. In this study, leather industry wastewater (LIW), which has high loads of contaminants, was treated using advanced treatment techniques instead of conventional methods. During the experiments, the performance of electrochemical methods was investigated. During the electrochemical experiments, the performance of batch electrooxidation (EO) using boron-doped diamond (BDD) electrodes with monopolar configuration for removal of chemical oxygen demand (COD) from LIW were investigated. The influences of electrolysis time, current density (which varies as 5 mA/cm², 10 mA/cm², 20 mA/cm², 30 mA/cm², 50 mA/cm²) and initial pH (which varies as 3,80 (natural pH of LIW), 7, 9) on removal efficiency were investigated in a batch stirred cell to determine the best treatment conditions. The current density applied to the electrochemical reactors is directly proportional to the consumption of electric energy, so electrical energy consumption was monitored during the experiment. The best experimental conditions obtained in electrochemical studies were as follows: electrolysis time = 60 min, current density = 30.0 mA/cm², pH 7. Using these parameters, 53.59% COD removal rates for LIW was achieved and total energy consumption was obtained as 13.03 kWh/m³. It is concluded that electrooxidation process constitutes a plausible and developable method for the treatment of LIW.

Keywords: BDD electrodes, COD removal, electrochemical treatment, leather industry wastewater

Procedia PDF Downloads 168

Authors: Qiang Li, Zhengfu Ning, Jun Li

Abstract:

In the domain of petroleum and gas production, the oil - water interface is of paramount importance, significantly influencing separation processes, fluid flow behaviors, and recovery efficiency. This study innovatively pioneers the utilization of electrolysis to modulate the properties of the oil - water interface, with the primary objective of enhancing fluid mobility and optimizing hydrocarbon recovery. This novel approach not only presents an innovative solution but also upholds environmental sustainability and operational efficacy. A series of experiments was meticulously designed, in which oil - water mixtures were subjected to direct - current (DC) voltages of 0V, 5V, 10V, and 15V. By employing advanced precision instruments, comprehensive measurements were carried out on the variations in oil - water interfacial tension, aqueous - phase cation concentration, pH value, crude - oil composition, and interfacial viscosity. A thorough exploration of the underlying relationships among these parameters was conducted to clarify the action mechanism of the DC electric field on the oil - water interface, thus providing a vital theoretical basis for optimizing oil and gas production techniques. The experimental results indicate that, under the influence of a DC electric field, the oil - water interfacial tension shows a remarkable decrease as the voltage increases. Specifically, when the voltage reaches 15V, the interfacial tension is reduced by nearly 20%. Simultaneously, the asphaltene content in crude oil decreases substantially, accompanied by a notable change in the ratio of saturated hydrocarbons to aromatic hydrocarbons. This is postulated to be a key factor contributing to the reduction in interfacial tension. Additionally, the increase in aqueous - phase cation concentration and the rise in pH value jointly promote the reduction of interfacial tension. Viscosity tests show that, under the same shear - rate conditions, the oil sample exposed to a higher voltage has the lowest viscosity, and as the shear rate increases, the viscosity of the oil sample exhibits a distinct downward trend. This research represents an innovative and environmentally - friendly strategy for regulating the oil - water interface, minimizing the dependence on chemical additives and alleviating environmental impacts. It provides novel perspectives and practical solutions for engineers involved in oil and gas extraction, potentially revolutionizing industry practices.

Keywords: oil - water interface, electrolysis, interfacial tension, hydrocarbon recovery

Procedia PDF Downloads 17

Authors: Christian C. Vaso, Rinlee Butch M. Cervera

Abstract:

Solid oxide electrolysis cell (SOEC) is a promising technology for hydrogen production that will contribute to the sustainable energy of the future. An important component of this SOEC is the anode material and one of the promising anode material for such application is the Sr-doped LaMnO3 (LSM) and Yttrium-stabilized ZrO2 (YSZ) composite material. In this study, LSM/YSZ with different weight percent compositions of LSM and YSZ were synthesized using solid-state reaction method. The obtained samples, 60LSM/40YSZ, 50LSM/50YSZ, and 40LSM/60YSZ, were fully characterized for its microstructure using X-ray diffraction, FTIR, and SEM/EDS. EDS analysis confirmed the elemental composition and distribution of the synthesized samples. Surface morphology of the sample using SEM exhibited a well sintered and densified samples and revealed a beveled cube-like LSM morphology while the YSZ phase appeared to have a sphere-like microstructure. Density measurements using Archimedes principle showed relative densities greater than 90%. In addition, AC impedance measurement of the synthesized samples have been investigated at intermediate temperature range (400-700 °C) in an inert and oxygen gas flow environment. At pure states, LSM exhibited a high electronic conductivity while YSZ demonstrated an ionic conductivity of 3.25 x 10-4 S/cm at 700 °C under Oxygen gas environment with calculated activation energy of 0.85eV. The composite samples were also studied and revealed that as the YSZ content of the composite electrode increases, the total conductivity decreases.

Keywords: ceramic composites, fuel cells, strontium lanthanum manganite, yttria partially-stabilized zirconia

Procedia PDF Downloads 320

Authors: Yu-Jen Shih, Juan-Zhang Lou

Abstract:

Nitrogenous compounds, such as NH4+/NH3 and NO3-, have become important contaminants in water resources. Excessive concentration of NH3 leads to eutrophication, which poses a threat to aquatic organisms in the environment. Electrochemical oxidation emerged as a promising water treatment technology, offering advantages such as simplicity, small-scale operation, and minimal reliance on additional chemicals. In this study, a nickel-based metal-organic framework (Ni-MOF) was synthesized using 2-amino terephthalic acid (BDC-NH2) and nickel nitrate. The Ni-MOF was further carbonized as derived nickel oxide and nitrogen-carbon composite, Ni/NiOx/NC. The nickel oxide within the 2D porous carbon texture served as active sites for ammonia oxidation. Results of characterization showed that the Ni-MOF was a hexagonal and flaky nanoparticle. With increasing carbonization temperature, the nickel ions in the organic framework re-crystallized as NiO clusters on the surfaces of the 2D carbon. The electrochemical surface area of Ni/NiOx/NC significantly increased as to improve the efficiency of ammonia oxidation. The phase transition of Ni(OH)2⇌NiOOH at around +0.8 V was the primary mediator of electron transfer. Batch electrolysis was conducted under constant current and constant potential modes. The electrolysis parameters included pyrolysis temperatures, pH, current density, initial feed concentration, and electrode potential. The constant current batch experiments indicated that via carbonization at 800 °C, Ni/NiOx/NC(800) was able to decrease the ammonium nitrogen of 50 mg-N/L to below 1 ppm within 4 hours at a current density of 3 mA/cm2 and pH 11 with negligible oxygenated nitrogen formation. The constant potential experiments confirmed that N2 nitrogen selectivity was enhanced up to 90% at +0.8 V.

Keywords: electrochemical oxidation, nickel oxyhydroxide, metal-organic framework, ammonium, nitrate

Procedia PDF Downloads 76

Authors: Hanene Akrout, Ines Elaissaoui, Sabrina Grassini, Daniele Fulginiti, Latifa Bousselmi

Abstract:

The main objective of this work is to investigate the efficiency of depollution power related to PbO₂ layer deposited onto a stainless steel (SS) substrate with SiOx as interlayer. The elaborated electrode was used as anode for anodic oxidation of wastewater containing Amaranth dye, as recalcitrant organic pollutant model. SiOx interlayer was performed using Plasma Enhanced Chemical Vapor Deposition ‘PECVD’ in plasma fed with argon, oxygen, and tetraethoxysilane (TEOS, Si precursor) in different ratios, onto the SS substrate. PbO₂ layer was produced by pulsed electrodeposition on SS/SiOx. The morphological of different surfaces are depicted with Field Emission Scanning Electron Microscope (FESEM) and the composition of the lead oxide layer was investigated by X-Ray Diffractometry (XRD). The results showed that the SiOx interlayer with more rich oxygen content improved better the nucleation of β-PbO₂ form. Electrochemical Impedance Spectroscopy (EIS) measurements undertaken on different interfaces (at optimized conditions) revealed a decrease of Rfilm while CPE film increases for SiOx interlayer, characterized by a more inorganic nature and deposited in a plasma fed by higher O2-to-TEOS ratios. Quantitative determinations of the Amaranth dye degradation rate were performed in terms of colour and COD removals, reaching a 95% and an 80% respectively removal at pH = 2 in 300 min. Results proved the improvement of the degradation wastewater containing the amaranth dye. During the electrolysis, the Amaranth dye solution was sampled at 30 min intervals and analyzed by ‘High-performance Liquid Chromatography’ HPLC. The gradual degradation of the Amaranth dye confirmed by the decrease in UV absorption using the SS/SiOx(20:20:1)/PbO₂ anode, the reaction exhibited an apparent first-order kinetic for electrolysis time of 5 hours, with an initial rate constant of about 0.02 min⁻¹.

Keywords: electrochemical treatment, PbO₂ anodes, COD removal, plasma

Procedia PDF Downloads 204

Authors: Belal Bakheet, John Beardall, Xiwang Zhang, David McCarthy

Abstract:

The potential risks associated with toxic cyanobacteria have raised growing environmental and public health concerns leading to an increasing effort into researching ways to bring about their removal from water, together with destruction of their associated cyanotoxins. A variety of toxins are synthesized by cyanobacteria and include hepatotoxins, neurotoxins, and cytotoxins which can cause a range of symptoms in humans from skin irritation to serious liver and nerve damage. Therefore drinking water treatment processes should ensure the consumers’ safety by removing both cyanobacterial cells, and cyanotoxins from the water. Cyanobacterial cells and cyanotoxins presented challenges to the conventional water treatment systems; their accumulation within drinking water treatment plants has been reported leading to plants shut down. Thus, innovative and effective water purification systems to tackle cyanobacterial pollution are required. In recent years there has been increasing attention to the electrochemical oxidation process as a feasible alternative disinfection method which is able to generate in situ a variety of oxidants that would achieve synergistic effects in the water disinfection process and toxin degradation. By utilizing only electric current, the electrochemical process through electrolysis can produce reactive oxygen species such as hydroxyl radicals from the water, or other oxidants such as chlorine from chloride ions present in the water. From extensive physiological and morphological investigation of cyanobacterial cells during electrolysis, our results show that these oxidants have significant impact on cell inactivation, simultaneously with cyanotoxins removal without the need for chemicals addition. Our research aimed to optimize existing electrochemical oxidation systems and develop new systems to treat water containing toxic cyanobacteria and cyanotoxins. The research covers detailed mechanism study on oxidants production and cell inactivation in the treatment under environmental conditions. Overall, our study suggests that the electrochemical treatment process e is an effective method for removal of toxic cyanobacteria and cyanotoxins.

Keywords: toxic cyanobacteria, cyanotoxins, electrochemical process, oxidants

Procedia PDF Downloads 256

Authors: Hongmei Yuan, Changyu Weng, Xinghua Zhang, Lungang Chen, Qi Zhang, Longlong Ma, Jianguo Liu

Abstract:

The climate crisis and the need for green and sustainable energy drive the rapid development of hydrogen production from water electrolysis. Improvements in the kinetics of the anode reaction, which governs the efficiency of water electrolysis, are essential for efficient hydrogen production and key to effectively addressing global environmental and energy challenges. Hence, we focus on improving the kinetics of the anode oxidation reaction. The multi-walled carbon nanotubes coupled with bimetallic organic framework (CoFe-MOF-74) composite electrocatalysts (CoFe-MOF-74@MWCNT) were fabricated for OER and the kinetically more favorable glucose oxidation reaction (GOR). Compared to commercial RuO2, CoFe-MOF-74@MWCNT showed superior OER catalytic performance, exhibiting a lower overpotential (273 mV) and a lower Tafel slope (55 mV dec-1) at a current density of 10 mA cm-2. Moreover, after adding glucose to the anode, the potential required of 10 mA cm-2 was only 1.291 V (vs. RHE), a reduction of 212 mV compared to the OER potential. This reduction in potential demonstrates the efficiency of our catalysts and signifies significant energy savings. The characterization results and theoretical calculations indicated that the superior OER/GOR performance of CoFe-MOF-74@MWCNT can be ascribed to the synergistic effect between MWCNT and the mixed metal nodes of the bimetallic organic framework. The doping of MWCNT promoted the catalyst charge transfer efficiency (Rct was only 5.56 Ω) in the OER process. The mixed metal nodes of CoFe-MOF-74@MWCNT provided more active sites for the electrocatalytic reaction and promoted the bond-breaking of critical intermediates in the oxidation process, significantly reducing the free energy of catalytic intermediates and accelerating reaction kinetics. This work provides a strategy for designing multifunctional electrocatalysts for OER and biomass small molecule oxidation and highlights the potential for significant energy savings in practical applications.

Keywords: bimetallic organic framework, multi-walled carbon nanotubes (MWCNT), synergistic effect, oxygen evolution reaction, glucose oxidation

Procedia PDF Downloads 8

Authors: Hamoud Al-Hadrami, Hossein Emadi, Athar Hussain

Abstract:

Green hydrogen is quickly emerging as a new source of renewable energy for the world. Hydrogen production using water electrolysis is deemed as an environmentally friendly and safe source of energy for transportation and other industries. However, storing a high volume of hydrogen seems to be a significant challenge. Abandoned hydrocarbon reservoirs are considered as viable hydrogen storage options because of the availability of the required infrastructure such as wells and surface facilities. However, long-term wellbore integrity in these wells could be a serious challenge. Hydrogen reduces the compressive strength of a set cement if it gets in contact with the cement slurry. Also, mixing hydrogen with cement slurry slightly increases its density and rheological properties, which need to be considered to have a successful primary cementing operation.

Keywords: hydrogen, well bore integrity, clean energy, cementing

Procedia PDF Downloads 236

Authors: Jarina Joshi, Pratap Kandel, Puja Bhatt, Suman Bajracharya

Abstract:

Biogas production and use in Nepal is very essential not only to combat fuel crisis but also for organic waste management. This paper deals with the integration of electrochemical systems in an anaerobic digestor to enhance biogas production with minimal electrical energy input. Biogas of 1.9 L was produced from the 1:2 v/v mixture of vegetable wastes in a downward water displacement collector and 0.8 V supplemented at 27℃. Biogas could be produced even at 18℃ i.e., 0.63 L), which is more than twofold in comparison with biogas produced without voltage i.e., 0.30 L). Maximum COD reduction was 70.84±5.54 % than in control (20.35±4.53 %). The digester is found to dwell three Bacillus strains and one Exiguobacterium strain when isolated manually from the sludge. From this study, supplementation of electricity in anaerobic digestor can produce more biogas and enhance waste degradation by transforming waste into energy.

Keywords: anaerobic digestion, biogas, microbial electrolysis cell, electrochemical, methanogens

Procedia PDF Downloads 23