Electrolytic Method Research Articles

Economic evaluation of hydrogen production in second and third units of Bushehr nuclear power plant regarding future need of nuclear fission technology

Today, the most important challenge for hydrogen production is the use of suitable energy source for sustainable production. The dual use of nuclear power plants allows them to expand into other markets by eliminating greenhouse gas emissions from processes such as hydrogen production. The significance of this matter especially in countries with ongoing new nuclear power plants is high and shows the future need for nuclear fission technology. In this paper, an economic assessment of hydrogen production in the second and third units of the Bushehr nuclear power plant (BNPP) with the Hydrogen Economy Evaluation Program (HEEP) is carried out and a comparison of CO2 emission in nuclear and non-nuclear methods of hydrogen production is presented. Most nuclear reactors, including Advanced Pressurized WaterReactor (APWR), High Temperature Gas Reactor (HTGR), and Water-Water EnergeticReactor (WWER), can be used as a source of thermal and electrical energy for the process of hydrogen production. In this research, hydrogen production processes based on the Conventional Electrolysis (CE), High Temperature Steam Electrolysis (HTSE), and Sulfur-Iodine (SI) Process using different storage and transportation options are compared to choose the cost-effective method for coupling with the WWER1000 reactor. Hydrogen production, thermal energy, and electricity costs have been calculated and explained in detail. The results showed that the cost-effective option for hydrogen production is using the High Temperature Steam Electrolysis (HTSE) method, Compressed Gas (CG) storage, and pipeline transportation, by 2.88 $/kg. Also, applying this method to produce hydrogen, the nuclear power plant thermal efficiency, and the hydrogen plant efficiency are kept in the best possible conditions by 51.98% and 58.21%, respectively.

Upcycling of spent LiMn2O4 cathode towards sodium-ion battery cathode through molten salt electrolysis approach

Recycling and valorizing spent lithium-ion batteries (LIBs) are requisite to achieve resource sustainability and environment safety. Herein, we reported a molten salt electrolysis method to recycle degraded LiMn2O4, synergistically achieving the selective leaching of lithium (Li) and high-valued reutilization of manganese (Mn). In molten Na2CO3-K2CO3, 94.3 % of Li from LiMn2O4 was released into molten salt by the electrolysis at 1.2 V for 7 h, while in-situ forming Na0.55Mn2O4⋅1.5H2O. During the electrolysis, LiMn2O4 at the cathode was electrochemically decomposed to Li2O and manganese oxide, accompanied by the reaction of resultant Mn oxide with Na2CO3 salt to generate Na0.55Mn2O4⋅1.5H2O. Finally, Li2CO3 in molten salt can be selectively extracted by water leaching. The obtained Na0.55Mn2O4⋅1.5H2O material as a sodium-ion battery (SIB) cathode delivers a discharge specific capacity of 58.9 mAh g−1 at 100 mA g−1, showing good cycle performance with a capacity retention of 93.9 % after 100 cycles. Hence, molten salt electrolysis achieves both extraction of Li and high-value reutilization of Mn, offering an electricity-driven materials separation, recovery, and reutilization with reduced environmental impact.

Combined PEO and Spray Pyrolysis Coatings of Phosphate and ZnO for Enhancing Corrosion Resistance in AZ31 Mg Alloy

Oxide films produced from plasma electrolytic oxidation are porous in structure. While they have some passivating effect in Mg alloys, the pores still lead to corrosion over long periods of exposure. In this study, spray pyrolysis was used to seal the porous oxide layer developed through the plasma electrolytic oxidation method on Mg alloy AZ31. The PEO coating acted as a good base for the application of spray pyrolysis due to its morphology. Three different kinds of coatings were obtained using different precursors: zinc acetate for ZnO, phosphoric acid for phosphate (P), and a mixture of zinc acetate and sodium phosphate for ZnO+P. The corrosion performance of all three coatings was studied by performing electrochemical impedance and polarization tests on the samples. Mass loss over a duration of 1 week was measured in 3% NaCl solution using immersion gravimetry. The coating with only phosphate (P) was found to be most corrosion-resistant with 52 times lower rate of corrosion and 50 times more polarization potential. The chemical composition of the corrosion products was studied using XRD and SEM-EDS analysis. Mass loss in ZnO+P was the highest, at up to 1.4 and 5.1 times higher than ZnO and P, respectively.

An Electrochemical Approach to Recycle and Extraction of Metals from Electronic Waste

Scraped e-waste is a result of increased production and demand for Electrical and Electronic Appliances (EEA). Because the discarded EEA contains heavy metals, it must be carefully disposed of in order to prevent any environmental harm. Researchers and pollution control boards in the relevant nations are taking notice of this rapid increase in e-waste in order to properly dispose of and recycle the garbage. A variety of materials, including gold, silver, copper, iron, etc., are included in e-waste. For research, it is crucial to safely and sustainably remove all of those metals from old electrical and electronic products. Electrochemical, pyrometallurgical, hydrometallurgical, and bioleaching methods for extracting metals from waste scrap have all evolved in the development of environmentally friendly and sustainable technologies. Among all the methods for extracting metals that are accessible, electrochemical extraction is one of the most admired. One of the reported most effective techniques among all of these is electrochemical. (80-95%) of the metal is reported to have been extracted using the previously stated procedure and various electrolytes. Additionally, after processing and chemical leaching of the Waste, various combinations of electrodes are employed to independently recover the metals from E-Waste is presented in the paper. The study presents an electrolysis method for copper extraction. In order to achieve the highest Cu extraction efficiency, a variety of electrode and electrolyte combinations are used in this study work, along with an energy model for the process. adjusting the electrolyte content to examine the Cu extraction rate for improved extraction efficiency. It is possible to extract copper with 99% efficiency using this electrolysis method.

Deposition and Morphology Control of Carbon Film through Electrochemical Reduction of Carbonate Ions in Molten LiCl

Synthesis of a compact, uniform and thick carbon film on nickel substrate were conducted by electrochemical reduction of carbonate ions in LiCl-Li2CO3 molten salt. It was found that the carbon is consistently formed into structure of wire and sphere particle. The uniformity and compactness of the carbon film were found to be dependent on the applied current density, electricity, and the electrolysis method. At lower current densities, the carbon tended to grow locally, resulting in larger-sized wires and particles. At higher current density, a relatively uniform and thin carbon film can be synthesized at the beginning but soon changed to a cluster-like structure. The contradiction between current density and carbonate ions‘ diffusion limit make it is impossible to obtain a compact and uniform film by using constant current electrolysis. By applying pulsed current electrolysis with an average current density of 10 mA cm−2 and a peak current density of 200 mA cm−2, a compact and uniform carbon film with a thickness of approximately 10 μm was successfully prepared.

Chromium Coating of Wollastonite Filled Polyamide 6 and Evaluation of Thermal Cycle Strength

The chromium coating of plastic/polymer materials through electrolysis method has attracted attention for improving material properties. The most common material used to be coated is the Acrylonitrile Butadiene Styrene (ABS), but has disadvantages compared to polyamides (PA), such as low thermal resistance. PA’s high water retention disadvantage can be substituted by using fillers such as clay, etc; so in this study, 40% Wollastonite filled PA has been used for chromium plating to increase the thermal resistance of the PA. The plates used were produced by injection molding method. The research is focused on the effect of time and concentration on coating performance in etching, activation (by palladium) and accelerator processes. SEM and EDX were used to characterize samples for surface morphologies and the microstructures of etching, activation and accelerator in the PA sub-plates. Additionally, cross-cut adhesion test has been applied to analyze the adhesion power of the interfaces. It was found that the thermal resistance of the metal plate on the polymer surface decreased as the time increased, in relation with the increasing wearing time of the metal plate mentioned above. The thermal resistance decreased as the polymer deformed in relation with the increase in etching solution’s concentration. It is also seen that the thermal resistance improved as the activation time increased. The adhesion and the thermal resistance did not improve as the time in accelerator process increased. Furthermore, the cross – cut adhesion tests on the same samples concluded that the results are in agreement with the other thermal resistance results.

Analytical Solutions to Characterize Through-Plane Inhomogeneity of Porous Electrodes Using Electrochemical Impedance Spectroscopy

Characterization of through-plane inhomogeneity in porous media requires knowledge of the distribution of porosity, tortuosity, and double-layer capacitance across the thickness. The thickness-averaged or apparent values of these parameters may not be sufficient to model the transport processes in batteries and fuel cells accurately. Cleverly designed through-plane inhomogeneities can improve the performance of electrochemical systems (e.g., graded-porosity electrodes for batteries or gas diffusion media for fuel cell). In some cases, inhomogeneity can result from manufacturing steps; for example, tortuosity variation due to binder migration in the fast slurry-drying step. In this work, we extend the impedance-based approach to characterize the inhomogeneity of a porous electrode in the through-plane direction. We derive analytical expressions for the impedance response of an electrode having three types of inhomogeneities (step-wise, linear, and inverse-linear variation) in a symmetric cell setup having non-reacting electrode/electrolyte interface (blocking electrode or electrolyte method). We also provide perturbation-theory based approximate solutions and expressions for semi-infinite domain to enable the development of an impedance-based fitting tool for inhomogeneous electrodes. In the end, we provide an impedance-based experimental investigation of gas diffusion media (composite layer) using symmetric cell setup to demonstrate the applicability of the theory and understanding derived in this work.

Current status of battery recycling and technology

In recent years, battery recycling has become one of the hot environmental issues in China. This paper analysis the current situation of battery recycling and the methods of recycling, and analyzes the effective means of recycling batteries under the existing conditions. The results show that the current situation of battery recycling in China is worrying, with no complete recycling industry chain and low recycling efficiency. And as the demand for batteries increases and the price of metals rises, the urgency of battery recycling is further increased. From the analysis of existing methods, pyrometallurgy is defective in many aspects and the environmental life cycle is not complete. The cost of electrolytic recycling method, although high recovery efficiency and wide range, requires adequate technology and high cost. Bioleaching method is highly efficient, low cost and produces almost no pollution. Although the technology is not mature enough and is still in the laboratory stage, the bioleaching method has a good future. This paper looks forward to exploring more appropriate recycling methods to address the current situation of battery recycling difficules in China and discusses the future prospects of these methods.

In English

The preparation of ceramic composites based on metal nanopowders allows us to change significantly the thermal characteristics of the ceramic matrix, which is important for the creation of heat-conducting ceramics technology. The work establishes the most efficient method of obtaining nickel nanopowder on a “P-5848” potentiostat by electrolysis of nickel sulfate (NiSO4) with the addition of boric acid (H3BO3), thiourea ((NH4)2CS) and nickel(II) chloride (NiCl2). The synthesis of Ni nanopowder was carried out at a current density from 1.0 to 3.3 A/dm2 and at a temperature of 45–65 °C, where a platinum (Pt) plate was chosen as an anode, and the cathode was specially made of especially pure aluminum (Al). The results of the study showed the synthesis of Ni nanopowder with a size of 55 nm in the form of thin scales. Electrochemical reactions at the cathode and anode are also considered in the work. Several successful experiments were also carried out in the work, which made it possible to develop an economically profitable technology for the synthesis of copper nanopowder by the electrolysis method at 13.3 ampere-hours of current per 1 dm2 of the anode surface at a relatively low temperature of the copper sulfate solution (CuSO4). Copper nanopowder is removed to the bottom of the bath from the anode by impact shaking. An equally successful experiment was carried out, where the cathode was in the form of several copper plates at the distance of 0.8 cm from each other with a voltage between them of 0.775 V, and a current density of 15.3 A/dm2 at the temperature of 54 °С in an electrolyte with 45 % H2SO4, 8 % Na2SO4 and 4 % CuSO4. The work contains tables with initial and final data of all experiments on the synthesis of nanopowders by the electrolysis method.

Preparation of titanium powder using a combined method of aluminothermic reduction and molten salt electrolysis

In this study, aluminothermic reduction and molten salt electrolysis were combined to prepare titanium powder. In this combined method, titanium dioxide was first deoxidized to produce titanium–aluminum alloy through an aluminothermic reduction reaction, and then the titanium–aluminum alloy was separated through chloride molten salt electrolysis to generate titanium powder. The obtained titanium powder, titanium aluminum alloy and slag was analyzed using several techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. A mass ratio of 2:3 of titanium dioxide and aluminum was suitable for the production of titanium–aluminum alloys. A large amount of alumina generated through the aluminothermic reduction reaction was separated into slag phases using cryolite. Then, the phases were electrolyzed into aluminum and cryolite, which were reused as raw materials. The final titanium–aluminum alloy product was electrolyzed in a chloride molten salt system to separate titanium and aluminum and produce titanium powder. Therefore, the combination of thermal reduction and molten salt electrolysis is efficient and has great potential for producing high-purity titanium powder.

Innovative developments on the use of hydrogen in transport internal combustion engines and power plants

BACKGROUND: Innovative technologies and design solutions aimed at using hydrogen in internal combustion engines and hydrogen power plants are reviewed in the paper. The advantages of hydrogen fuel are shown and the main problems that Western automakers face and which determine the ways to solve problems in road transport are identified. In this regard, the method of using hydrogen energy in internal combustion engines and hydrogen power plants becomes a decisive factor.
 AIMS: Search for a reasonable and effective method of using hydrogen in transport.
 METHODS: The technologies of hydrogen production with the electrolysis method and on-board generation of hydrogen using hydrogen-containing components are considered. It is proposed to use ammonia as a hydrogen carrier reagent for operation in dual-fuel diesel internal combustion engines.
 RESULTS: It is noted that ammonia, with a high level of hydrogen content in the molecule, is relatively safe, has a low cost and a significant volume of production. It is easier to store and transport compared to hydrogen. For internal combustion engines operating on hydrocarbon fuel, the use of ammonia and hydrogen, its derivative product, is attractive due to the need to remove highly toxic nitrogen oxides containing in the exhaust gases of diesel internal combustion engines.
 One of the main problems of creating an environmentally friendly diesel engine associated with reducing the NOx content to an environmentally safe level is considered. A positive factor of using ammonia is the on-board production of hydrogen in the thermal reactor, as well as the possibility of organizing an effective process of neutralizing nitrogen oxides in a diesel engine.
 CONCLUSIONS: The use of ammonia to generate hydrogen allows the diesel engine to implement the process of selective reduction of nitrogen oxides when ammonia is injected into the combustion chamber at the exhaust stroke. This method will significantly increase the efficiency of NOx neutralization in a diesel internal combustion engine due to the possibility of temperature regulation of the NOx neutralization reaction directly in the cylinder and in the exhaust system of the internal combustion engine.

Graphene dot-embedded porous WO3 photoanode for highly efficient photoelectrochemical water splitting

The development of semiconductor photoanodes with improved photoelectrochemical (PEC) efficiency and stability for the purpose of realizing solar water splitting is a crucial challenge that carries substantial practical implications. In this study, GQDs/WO3 composite porous photoanodes were fabricated using a pulsed anodization method in an aqueous electrolyte containing hydroxyl GQDs. The morphology and crystal structure of the as-prepared GQDs/WO3 porous films were characterized by SEM, TEM, XRD, XPS, Raman spectra, and FTIR. The successful embedding of GQDs into the WO3 walls to form tightly bound heterojunctions was confirmed. It was investigated how the GQD content influenced the photoelectrochemical properties of the GQDs/WO3 heterojunctions. The optimal photocurrent densities observed in the GQDs/WO3 samples (10-WO3) were found to be three times higher compared to those obtained from pure WO3 porous films. This significant enhancement clearly indicates the positive impact of GQDs on the PEC performance. The boosted PEC activity of the GQDs/WO3 heterojunction photoanode was attributed to the fact that the introduction of GQDs promotes more efficient light absorption, charge separation, and transport processes within the heterojunction structure. Moreover, the GQDs/WO3 composites photoelectrodes exhibited excellent PEC stability, predicting its enormous potential for practical applications.

Biodiesel production from Mastic oil via electrolytic transesterification: optimization using response surface methodology and engine test.

This study aimed to synthesize the biodiesel from Mastic oil by electrolysis method. Mastic gum is a potential and inexpensive feedstock for the biodiesel production. The oil content of Mastic gum was ~ 20% of the total gum weight. The gas chromatography-mass spectrometry (GC-MS) analysis was exploited to measure the oil's fatty acid profile. The response surface methodology (RSM) via Box-Behnken design (BBD) was utilized to specify the best processing condition of the electrolytic transesterification process. According to the RSM-BBD results, the highest predicted biodiesel yield was 95% at the reaction time of 1 h, methanol to oil ratio of 4:1, and catalyst weight of 1.2 wt%. Under these conditions, the produced Mastic oil biodiesel was blended with the neat diesel at different volume ratios of 5:95 (B5), 10:90 (B10), and 15:85 (B15). These fuel mixtures were tested in a single-cylinder engine to assess engine performance and exhaust emissions. The experiments exhibited that blending biodiesel with diesel can slightly improve the engine performance. Moreover, the application of blends with high volumes of biodiesel decreased the exhaust emissions, such as carbon monoxide (CO), carbon dioxide (CO2), and unburned hydrocarbons (UHC) by 54.54%, 41%, and 39.3%, respectively. However, the nitrogen oxide (NOx) emission increased because of the higher oxygen content of the biodiesel. It was also found that the physical and chemical characteristics of the Mastic oil biodiesel are the same as diesel, consistent with the ASTM standard. The Fourier transform infrared (FTIR) analysis also confirmed the biodiesel production.

Characterization and formation mechanism of non-metallic inclusions in single bcc-phase high entropy alloy

This work aims to provide a fundamental study of inclusion characteristics in the single bcc-phase high entropy alloy (HEA), Mn-rich and Al-contained multicomponent system (Al-Cr-Mn-Fe-Co-Ni) was selected as the prototype alloy in this study. According to the differential thermal analysis (DTA) measurements, the solidus (TS) and liquidus (TL) temperatures of this alloy were in the range of 1225–1228 °C (1226 ± 2 °C) and 1268–1271 °C (1270 ± 2 °C), respectively. Non-metallic inclusions were investigated in a two-dimensional (2D) cross-section method as well as extracted by a three-dimensional (3D) electrolytic extraction method. It was found that AlN was the dominant inclusion phase, also a small amount of Al2O3 inclusions were observed. They formed in the liquid alloy and mostly presented as Al2O3-AlN agglomerates, where the size range of the AlN inclusions was larger than that of Al2O3. The theoretical calculation showed that AlN inclusion has a higher coagulation coefficient and collision rate than those of Al2O3 inclusions, which agrees well with the experimental observations. The inclusion characteristics of Al2O3 and AlN were closely related to the relative contents of O and N in the presence of high Al content in the alloy. The impurity elements of N and O were the key issues in controling the stable inclusion phase in high entropic alloy.

Achieving high replicability for electrochemical machining via the stamp flushing method in stationary electrolyte

Traditional high-speed electrolyte flow for removing bubbles and sludges from the inter-electrode gap during electrochemical machining (ECM) usually results in the non-uniform distribution of temperature, bubbles, and sludges, thus deteriorating machining accuracy. Therefore, ECM performed in stationary electrolyte via an efficient flushing method may solve this problem. For this reason, the previous study proposed the stamp flushing method to squeeze out the bubbles and sludge from the inter-electrode gap by shortening the gap width. However, the effectiveness of the stamp flushing method in achieving high replicability has not been systematically investigated. In the present work, the stamp stroke motion was first optimized to improve the flushing efficiency of the stamp flushing method. To obtain higher stamping velocity and to avoid the damage due to the collision between the tool electrode and workpiece, a cushion mechanism was newly installed on the equipment. Based on the optimized stamp stroke motion, the periodical micropatterns fabricated on the tool electrode surface using wire electrical discharge machining (WEDM) were replicated onto the SK4 workpiece using ECM in stationary electrolyte. The dimensional deviation of the workpiece from the tool electrode after ECM was less than 4 μm in the feed direction and approximately 30 μm in the side direction when the initial width of the frontal gap was 10 μm. Outside the inter-electrode gap, the electrolyte flowing along the axial direction (EFAAD) was supplied to rapidly flush out the bubbles and sludge squeezed out by stamp motion to prevent them from backflowing into the inter-electrode gap during the widening phase of the gap after the stamp motion. Since the EFAAD does not affect the electrolyte in the inter-electrode gap, the ECM remains performed in a stationary electrolyte. High replicability was obtained uniformly over the working surface, which originates from the combined effect of small inter-electrode gap width and uniform distribution of temperature, bubbles, and sludge in stationary electrolyte. This work proves the potential of the proposed stamp-flushing method for manufacturing metal parts with high replicability.

(Keynote) Experimental Insights for Extra-Terrestrial Application of Molten Oxide Electrolysis

Molten oxide electrolysis (MOE) has been considered for several decades for oxygen generation from extra-terrestrial oxides. It consists in the electrolytic decomposition of the rocks or soils, which are mixture of the common earth oxides (silica, iron oxide(s), alumina, magnesia...). Therein the oxides mixture is acting as the electrolyte, in the molten state. The target anodic product is oxygen gas, and the cathodic product is a metal. In one version of MOE, the temperature is high enough to sustain the production of a liquid metal, offering the opportunity to conceive a fully continuous process thanks to periodic tapping of the cathodic product. A key attribute of such approach is the high current density (productivity) that can be anticipated thanks to the high concentration of oxygen and metal present in the electrolyte. This leads to electrochemical engineering questions that are not commonly discussed in other electrolysis methods. This presentation offers to review some of the prior findings related to the underlying thermodynamic of the process, as well as the oxygen evolution and transport phenomena that support the development of MOE. Recent findings combining a container-less method and advanced electrochemical techniques will be presented.

Rhenium Electrodeposition to Enable Functionally Graded Films

Rhenium (Re) has one of the highest melting points of all the metals with a high modulus of elasticity and superior tensile strength when compared to other refractory metals. However, processing challenges from the high temperature stability combined with the relative occurrence require advanced manufacturing approaches to leverage the unique properties of rhenium. The electrodeposition of rhenium has received renewed attention in the past decade as a scalable approach to apply uniform coatings to enable a wide range of applications in aerospace, nuclear, catalysis, biomedical fields. However, Re has traditionally been difficult to deposit by electrolysis from aqueous solutions due to the over potential for hydrogen evolution and complex electrochemical reactions.Beginning with the perrhenate anion (ReO4 -), reduction from the +7 oxidation state must occur to deposit metallic Re. The exact mechanism of this process is still unknown with reductions to ReO2, ReO3, and Re2O5 along with metallic Re. Combined with the hydrogen evolution reaction, Re coatings are generally deposited at low faradaic efficiency, are brittle, and limited in the obtainable thickness (sub-micron).Herein, we present systematic studies progressing towards the development of stable and efficient electrolytes to enable the electrodeposition of thick (100+ microns) Re coatings. Borrowing the water-in-salt electrolyte method from the lithium battery literature enables near room-temperature electrodeposition of Re. Specifically, we correlate nucleation and growth mechanisms of Re with the ability produce thick coatings. Pulse/pulse reverse electroplating was applied to manipulate the obtained grain structure and distribution of rhenium moieties. Correlations between the electrolyte composition and the pulse parameters with the observed morphology will be discussed with an emphasis on enabling industrially relevant electroplating processes.The goal of this project is the electrodeposition of rhenium-cobalt (Re-Co) graded compositional/density samples of millimeter thickness. Thus, understanding how to transition from a coating or pure metallic rhenium to a graded composition of Re-Co as a function of dynamic processing conditions will be presented.

Plasma Electrolytic Oxidation of AZ31 Mg Alloy in Bipolar Pulse Mode and Influence of Corrosion to Surface Morphology of Obtained Coatings

The plasma electrolytic oxidation method was used with AZ31 magnesium alloy plates for improving the corrosion resistance of the alloy. Process parameters for the plasma electrolytic oxidation setup were optimized by studying the effects of KOH concentration, operating voltage, and pulse properties on the obtained coating. These conditions were then used to produce plasma electrolytic oxidation coated AZ31 sample and were tested by immersion in 3 % NaCl solution for 1 week. Three types of modifiers were used in the electrolyte and concentrations of the modifiers were varied to study the effect of concentration on the performance of coating obtained. The extent of corrosion was visually examined, and it was found that an electrolyte recipe with all three modifiers produced the best results.

A compact production plant model for green hydrogen production from medium temperature geothermal resources: A case study of the Van Lake-Zilan location

Considering the abundance of renewable energy potential in Turkey, green hydrogen derived from renewable sources holds great promise as a fuel. This paper presents a model for obtaining green hydrogen from medium-temperature geothermal sources. In this model, the Zilan location in the Van province of Turkey was identified as a suitable site for electricity and hydrogen production from low or medium-temperature geothermal sources due to its significant geothermal and water resource potential. In this regard, the installed capacity of the Organic Rankine Cycle (ORC) geothermal power plant is determined by using Monte Carlo Simulation based on the characteristics of the geothermal well at this location, and subsequently, the hydrogen production performance has been evaluated by analyzing the water of Lake Van. According to the analysis results, Lake Van was found to be efficient for hydrogen production. Hydrogen production from Lake Van water was subsequently simulated using the electrolysis method with this ORC geothermal power plant. According to the findings of this model, the hourly hydrogen production potential at this location using a 1.4 MW ORC plant, based on 2022 data, was estimated to be 18.6 kg, which is projected to increase to 28 kg based on 2050 estimated data. In addition, the techno-economic analysis of this compact green hydrogen production process was conducted in the study. The production cost of 1 kg of hydrogen was calculated to be €4.91 in 2022, while it is expected to be €1.21 in 2050. These results indicate that ORC technology will become competitive in hydrogen production in the upcoming years.

Effect of the Addition of Graphene Flakes on the Physical and Biological Properties of Composite Paints.

In this study, graphene flakes were obtained using an electrolytic method and characterized using X-ray diffraction (XRD), Raman and FTIR spectroscopy, scanning and transmission electron microscopy (SEM/TEM). Graphene-based composites with varying concentrations of 0.5%, 1% and 3% by weight were prepared with acrylic paint, enamel and varnish matrices. The mechanical properties were evaluated using micro-hardness testing, while wettability and antimicrobial activity against three pathogens (Staphylococcus aureus 33591, Pseudomonas aeruginosa 15442, Candida albicans 10231) were also examined. The results indicate that the addition of graphene flakes significantly enhances both the mechanical and antimicrobial properties of the coatings.