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chemicaltech · 2 years

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Hydrogen Electrolyzer Market Pegged for Robust Expansion by 2031 | Type, Application, Scope & Key Companies

Global Hydrogen Electrolyzer report from Global Insight Services is the single authoritative source of intelligence on Hydrogen Electrolyzer market. The report will provide you with analysis of impact of latest market disruptions such as Russia-Ukraine war and Covid-19 on the market. Report provides qualitative analysis of the market using various frameworks such as Porters’ and PESTLE analysis. Report includes in-depth segmentation and market size data by categories, product types, applications, and geographies. Report also includes comprehensive analysis of key issues, trends and drivers, restraints and challenges, competitive landscape, as well as recent events such as M&A activities in the market.

A hydrogen electrolyzer is a device that uses electrolysis to produce hydrogen gas. Electrolysis is a process that uses an electric current to split water molecules into hydrogen and oxygen atoms. Hydrogen electrolyzers are used in a variety of applications, including fuel cells, chemical production, and water treatment.

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Market Segmentation

The Hydrogen Electrolyzer Market is segmented by type, capacity, end-user and region. By type, the market is classified into proton exchange membrane (PEM) electrolyzer, alkaline electrolyzer, anion exchange membrane (AEM) electrolyzer, and solid oxide electrolyzer. By capacity, the market is bifurcated into below 500 kW, 500 kW – 2 mW, and above 2 mW. By end-user, the market is divided into ammonia, methanol, refining/ hydrocarbon, transport, and others. Region-wise, the market is analyzed across North America, Europe, Asia Pacific, and rest of the World.

Key Players

The key players in the Hydrogen Electrolyzer Market are Nel Hydrogen, Siemens AG, McPhy Energy, ITM Power Plc, Gaztransport & Technigaz, GreenHydrogen Systems, iGas Energy GmbH, Next Hydrogen., Asahi Kasei, thyssenkrupp nucera, Hydrogenics (Cummins), Toshiba Corporation, Plug Power, John Cockerill, H2Greem, Sunfire GmbH, Bloom Energy, and Hydrogen Optimized Inc.

Key Drivers

The key drivers of the hydrogen electrolyzer market are the growing demand for clean energy, the declining cost of electrolyzers, and the increasing government support for hydrogen fuel cell technology.

The demand for clean energy is increasing as the world becomes more aware of the impact of greenhouse gas emissions on the environment. Hydrogen is a clean energy source that can be used to power fuel cells, which produce no emissions.

The cost of electrolyzers has been declining as the technology has become more efficient. The cost of hydrogen fuel cells has also been declining, making them more attractive as an alternative to traditional fossil fuel-powered vehicles.

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intelligentliving · 4 years

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An ideal power sector scenario for a clean and sustainable future would involve the harvesting of wind and solar energy for electricity, and using the excess energy to power electrolyzers – water splitters that produce hydrogen fuel (H2). The H2 can be stored long-term to provide a means of generating...

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zvaigzdelasas · 4 years

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To develop their membrane, the scientists used a novel method: they chemically bonded two commercially available polymers [(PPO) and (SEBS)] without using a crosslinking agent. Professor Tae-Hyun Kim from Incheon National University, who led the study, explains, "A previous study made a similar attempt to fabricate anion exchange membranes (AEMs) by crosslinking PPO and SEBS with diamine as a crosslinking agent. While the AEMs displayed excellent mechanical stability, the use of diamine could have led to different reactions other than those between PPO and SEBS, which made it difficult to control the properties of the resultant membrane. Therefore, in our study, we crosslinked PPO and SEBS without any crosslinking agent to ensure that only PPO and SEBS react with each other." The strategy used by Prof. Kim's team also involved adding a compound called triazole to PPO to increase the membrane's ion conductivity.

Membranes fabricated using this method were up to 10 μm thin and had excellent mechanical strength, chemical stability, and conductivity at even a 95% room humidity. Together, these conferred a high overall performance to the membrane and to the corresponding fuel cell on which the scientists tested their membrane. When operated at 60°C, this fuel cell exhibited stable performance for 300 hours with a maximum power density surpassing those of existing commercial AEMs and matching cutting-edge ones.

Excited about the future prospects of this novel promising AEM, Prof. Kim says, "The polymer electrolyte membranes in our study can be applied not only to fuel cells that generate energy, but also to water electrolysis technology that produces hydrogen.

17 Feb 2021

#hfc

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joyfuldelusionchaosvaliant · 3 years

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Science and Chemistry Classes

New ferrocenium-based anion-exchange membranes for fuel cells

Ingrid Fadelli , Tech Xplore

Anion exchange membranes (AEMs) are semipermeable fuel cell components that can conduct anions but reject cations and gases. This enables the partition of substances that could chemically react with one another, thus allowing the cells to operate properly.

A team of researchers at Tianjin University in China have recently developed new types of AEMs that are based on a newly designed ferrocenium material. Their membranes, presented in a paper published in Nature Energy, were found to achieve highly promising results in terms of power output, durability, and ohmic resistance.

"As the oriented mixed-valence ferrocenium material developed in our study is entirely new for the AEM field, we encountered many difficulties and frustrations along the way," Michael D. Guiver, one of the researchers who carried out the study, told TechXplore. "We spent a long research period and much effort, both experimentally and theoretically, to achieve these good outcomes. The whole process from initial conceptualization to final publication was convoluted, but fortunately successful."

The recent study by Guiver and his colleagues builds on two of their previous works, where they introduced new proton exchange membrane materials that were magnetically responsive and had conducting capabilities. The ultimate goal of their previous studies was to orient conductive channel structures under a magnetic field, which would in turn extend alignment strategies to the field of AEMs.

"While it builds on our past efforts, our study is also an independent pioneering work, as it employs different material systems in a different field," Guiver said. "Our primary objectives were to build through-plane oriented highly conductive channels in AEMs, to promote anion transport because of the more aligned and direct conductive channels, and concurrently realize robust membrane durability in fuel cell application. We were happy to achieve both."

To ensure that the polymer they developed would be an effective AEM and that it could be influenced by magnetic fields, the researchers initially started looking at a material system that contained iron, namely ferrocene. Some past studies had explored similar materials (i.e., metallocenes), such as cobaltocene, and found that AEMs based on these materials achieved a good stability and high conductivity. However, past findings found that metallocenes could not align under magnetic fields, as they are not paramagnetic.

"An alternative possibility was to use ferrocene, which when made into a polymer, and oxidized, might be paramagnetic and also bear the positive charge needed to function as an AEM," Guiver explained. "However, the use of iron molecules in fuel cell membranes has been largely avoided, because in some forms, they accelerate degradation."

In their previous work, Guiver and his colleagues had introduced ferrocyanide into proton exchange membranes. When they did this, they found that some materials containing iron could improve the stability of fuel cells. Inspired by these results, they now decided to explore the potential of using polymers containing ferrocene as AEMs, which had so far never been assessed.

"Our study focused on both high performance and robust durability of AEMs," Guiver said. "The ferrocenium material with both magnetic responsiveness and conducting ability cast under magnetic field realized conducting channel alignment, and the mixed-valence ferrocenium-ferrocene state induced by magnetic field led to very good durability."

The new ferrocenium-based AEMs introduced by Guiver and his colleagues have a magnetic field-oriented and conductive structure. In addition, they have a robust durability, with a 3.9% voltage loss and a 2.2% high-frequency resistance increase over 500 h at 500 mA cm−2, 120 °C and 40% relative humidity.

"For anion transport, most anion-exchange membranes show isotropic conductivity (i.e., the same amount of conductivity in the in-plane and through-plane direction)," Guiver said. "Ideally, since anions transport between electrodes across the membrane (i.e., through-plane direction), shorter and more direct channels should be a big benefit to make the cell perform well."

To enhance membrane durability, conventional AEMs typically include positively charged materials containing nitrogen. While the use of these materials can be effective in making cells more durable, often they result in issues with stability, due to chemical reactions that cause cell degradation. As the membranes created by Guiver and his colleagues combine a through-plane-oriented conductive structure with an alternative anion conductor based on ferrocenium, they could help to circumvent these key drawbacks of conventional AEMs.

"We were the first to use ferrocenium cations, allowing through-plane oriented conductive structure, and the mixed-valence state, affording extraordinary durability," Guiver explained. "These findings can be distilled into the following outcomes: high membrane hydroxide conductivity in the through-plane direction; no appreciable conductivity loss over an alkali stability test period of 4,320 hours (180 days); simultaneous improvements in both conductivity and stability; lowest membrane thickness-normalized high-frequency resistance; and operation and considerable durability at 120 °C and 40% relative humidity."

In the future, the AEMs introduced by this team of researchers could be used to develop stable, durable, and highly performing fuel cells that can operate for a long time at elevated temperatures. The initial results gathered by Guiver and his colleagues suggest that their membranes could promote reaction kinetics on electrodes, as well as the migration of catalyst poisoning by CO and membrane carbonation from CO2 by high-temperature desorption/purging. In addition, they could help to simplify cell cooling and humidification systems.

"Our membranes could also facilitate the alleviation of water flooding in the anode, enhance water diffusivity through the membrane to overcome water management issues, and improve the efficiency of waste heat caused by an increased temperature difference between cell stack and coolant," Guiver added. "We are now developing alternative material systems with both external field responsiveness and conducting ability. We aim to achieve stronger orientation under weaker magnetic field, which would decrease cost and allow commercial scalability."

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juniperpublishersajop · 3 years

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Ion Exchange Membrane for Reverse Electrodialysis

Abstract

Ion exchange membranes (IEMs) are used for exchanging or removing ions from the solutions so that they are fabricated by polymers rather than metals or ceramics. When metal is in contact with the solutions, some reaction or corrosion occurs, and ceramic is difficult to use in membrane form because it is brittle. Also, normal metals and ceramics do not have high ion-exchange properties so that polymers are used widely as a host material of the IEM. The conventional IEMs are either layered membrane consisted of ion exchange material and support layer, and thick bulk membrane. There are no critical problems to use them for water treatment, but they are not suitable for electrochemical application such as reverse electrodialysis (RED). RED is a method of making electricity by sequential ion transport through semi-permeable membranes and electrochemical reaction at the electrode part so that the IEMs need to be developed for getting the structure not to interfere with ion movement through the IEM body. In the RED system, the IEMs are involved in separating ions to create the chemical potential which makes a voltage in the electrochemical system. IEMs for RED has not yet been widely adopted, and most of them are the membrane for electrodialysis (ED). Therefore, we need to study engineering approaches to improve the IEM properties.

Keywords: Ion exchange membrane; Cation exchange membrane; Anion exchange membrane; Polymer; Composite; Structure engineering; Reverse electrodialysis

Introduction

Ion exchange membrane (IEM) is a semi-permeable membrane that consisted of various polymers. When giving the driving force of ion transport, IEM allows the counter-ions and rejects the co-ions [1]. The IEM determines the mobility and selectivity of the ions with assumed that the same driving force is given in the system. There are two types of IEM according to the fixed charge in their body, cation exchange membrane (CEM) and anion exchange membrane (AEM). CEM has a negative charge, thereby the anions are rejected and the cations are exchanged by CEM. On the contrary, since AEM has a positive charge, the cations are rejected and the anions are exchanged by AEM (Figure 1). In addition, IEMs are classified into homogeneous and heterogeneous membranes according to their features. Homogeneous membranes can be fabricated by polymerization of monomers or blending and grafting polymers with different moieties [2-4]. Homogeneous membranes have evenly distributed fixed charges throughout the entire body so that uniform properties appear in all regions. Heterogeneous membranes can be obtained by blending charged resin with a binder and casting them on support [5,6].

Usually, the fixed charge distribution of heterogeneous membrane is uneven compared to homogeneous membrane due to the intrinsic drawback of the manufacturing process. In general, therefore, homogeneous membranes have better ion exchange properties than heterogeneous membranes, but heterogeneous membranes are mechanically strong compared to homogeneous membranes. However, both types of membranes can improve their properties through material or structural engineering. There are many high-quality commercial products in the market (Table 1). In the case of CEMs, the most representative commercial product is the Nafion from DuPont. It has a thickness of 178 nm, IEC of 0.84 meq/g, and exact permselectivity is unknown [7]. NEOSEPTA CM-1 of ASTOM, Selemion CMV of Asahi glass, RALEX CM(H)-PES of MEGA, and CEM type 1 of FUJIFILM are also well-developed CEMs. These products showed a thickness of 100-450 nm, IEC levels of 0.84-2.30 meq/g, and permselectivity of 92.0 -98.8% [5,8]. In the case of AEM, CJMA-2 of Hefei chemjoy, NEOSEPTA AM-1 of ASTOM, Selemion AMV of Asahi glass, RALEX AM(H)-PES of MEGA, and AEM type 1 of FUJIFILM exhibited thickness of 110- 450 nm, IEC values of 0.80-2.20 meq/g, and permselectivity of 90.0-95.0% [5,9-13].

Features of the conventional ion exchange membranes

The conventional IEMs have been developed in an aspect of IEC and mechanical endurance because the conventional products are generally used for adsorbing/exchanging ions to the membrane surfaces in a field of water treatment or ED. These are either layered structure that consisted of ion exchange and support layers or the thick bulk membrane that composed with ion-exchange resin and binder polymer (Figure 2). These type of membranes showed excellent performances for exchanging ions in solution or eliminating specific ions from water, but not suitable to maximize the power density of the applications that ions need to move in an opposite area through the IEM, such as RED. The ions would be hindered physically by a support layer or membrane body in conventional cases, no matter how much other properties are excellent. Thus, the idea that finding a novel material, developing a new surface treatment technique, and conducting structural engineering needs to be considered for fabricating novel IEMs for RED. The RED can be an alternative to overcome the dependency of climate and time for producing electricity because it uses saline water as an energy source. Also, there is no pollutant emission during power generation from the RED system.

The important parameters of the IEM for RED system are the thickness, membrane structure, IEC, areal resistance, and permselectivity, etc. [14-16]. Among them, the thickness and structure of the IEM influence critically the performance of the RED system because it affects how ions move smoothly by penetrating the IEM body. Another thing to consider is the selectivity between cation and anion. If the ion penetrates the IEM easily, the selectivity of IEM is low because it has a trade-off relation between ion conductivity and selectivity. Therefore, it is very important to develop IEMs which has high ion conductivity and selectivity, simultaneously, for expanding the application area of IEMs to electrochemical energy generation.

Operating mechanism and stack configuration of the RED system

The RED system can convert ionic to electric current by circulating two feed solutions that have different salinity, it is just an inverse procedure of the ED system. Salts or solutes in feed solutions are adsorbed to IEM by the induced potential difference between electrodes in the ED process so that the dilute and the concentrate are obtained [14,17]. However, RED makes the ions transport through the IEMs without an applying potential, and current is generated by a redox reaction at the electrode parts. In other words, the concentration difference between the two feeds is the driving force to move the ions, and the alternating CEM and AEM make the ions separate. Thus, high and low salinity solutions need to be supplied alternately across the IEMs for inducing concentration difference. The separation of cation and anion creates a chemical potential in the system so that electrochemical reactions occur to generate electric current (Figure 3) [18-21]. The larger the concentration difference, the higher the power density can be obtained theoretically, but the power density would be decreased owing to an increase of internal resistance in the real case. To enhance the maximum power density, it needs to maintain a high concentration difference between the two feeds with preventing the increase of internal resistance at the same time. IEM is the key to solve this issue. If the IEM performance is improved, the internal resistance of the system would be maintained at a low level even the concentration difference is increased. Therefore, the power density of RED can be determined by the properties of IEM assuming that all conditions of the systems are constant.

Tailor-made ion exchange membranes

Many commercial IEMs are on the market, but they still need to develop for adopting in electrochemical energy generation by overcoming their drawbacks. The methods related to cross-linking (or grafting) other polymers, and incorporating hetero materials on the membrane have been studied. Pal S, et al. [22] evaluated homogeneous phase crosslinked poly(acrylonitrile-co-2-acrylamido-2-methyl-1-propanesulfonic acid) (PAN-co-PAMPS) network CEM with controlling the mol ratio of monomers (AN and AMPS) [22]. By using a PAN-PAMPS-1 membrane including 15 mol% PAMPS, pretty good mechanical ability (tensile strength of 16.4 Mpa) and electrochemical performance (FCD of 0.757 meq/cm3 and transport number of 0.92) were obtained due to its uniform phase mixing of ionic domains and hydrophobic domains. Y. Chen’s group attempted to blend nanoparticles in IEM that were organic-inorganic nanocomposite CEMs such as sulfonated iron (III) oxides (Fe2O3-SO42‒) [23,24] and sulfonated silica (SiO2-SO3H) [25] to improve the IEC, resistance, and permselectivity. The Fe2O3-SO42‒/sPPO nanocomposite CEM was prepared by phase inversion method using the mixture of Fe2O3-SO42‒ particles and sPPO solution. This IEM showed AR of 0.82 Ω cm2, permselectivity of 85.6%, and enhanced gross power density of 1.4 W/m2 [23]. SiO2-SO3H/sPPO nanocomposite CEM was fabricated by phase inversion using the mixture solution. It exhibited AR of 0.85 Ω cm2 and higher gross power density than that of commercial CEM (1.3 W/m2) [25].

Yang S, et al. [26] incorporated ion exchangeable materials into the porous membrane. This is a roll-to-roll (R2R) pore-filling process consisting of pretreatment, impregnation, photo-polymerization, and polishing. The filler material was synthesized by mixing anionic/cationic electrolyte, crosslinking agent, and a photoinitiator. Thus, both CEM and AEM can be fabricated, respectively, depending on which electrolyte is selected and mixed. The pore-filled CEM (PCEM) showed IEC of 1.839 meq/g, AR of 0.475 Ω cm2, and permselectivity of 96%. Also, the pore-filled AEM (PAEM) exhibited IEC of 1.645 meq/g1, AR of 0.661 Ω cm2, and permselectivity of 94.3% [26,27]. Gao H, et al. [9] engineered the surface of AEMs via layer-by-layer (LBL) method with negatively charged poly(styrenesulfonate) (PSS) and positively charged poly(ethyleneimine) (PEI) polyelectrolytes. This membrane has 7.5 bilayers showed excellent anti-organic fouling characteristics and permselectivity. the antifouling potential also increased 30.29% higher than the pristine membrane and the ratio of transport number between Cl- and SO42- was improved from 1.10 (pristine) to 2.44. These results consequently have been enhanced the power density generation of RED by up to 17% [9]. Hong JG, et al. [28] fabricated the hybrid IEMs by the chemical reaction using poly (diallyldimethylammonium chloride) (PDDA) for AEMs and the sulfated polyvinyl alcohol (sPVA) as a hydrophilic polymer with sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) (sPPO) for CEMs to improve AR, permselectivity, and power density [28-30]. R.A. Tufa et al. fabricated a polymer layer consisted of polypyrrole (PPy) and chitosan (CS) to prohibit the passage of the multivalent ions. The modified IEM showed improvement of open circuit voltage (OCV) and power density of 20% and 42%, respectively, compared to the pristine IEM [31].

Conclusion

Since the past, IEMs have been developed with the application of various polymer materials. As a result, high-quality commercial IEMs are being distributed on the market in recent years. These are quite suitable for application in the water treatment field, but their disadvantage is poor ionic conductivity for electrochemical energy applications. Therefore, as the researches introduced briefly in this review, it is necessary to continuously try to apply various materials on IEM, and further studies to suggest a novel structure of the membrane are also needed.

For more Open Access Journals in Juniper Publishers please click on: https://juniperpublishers.com/

For more articles in Academic Journal of Polymer Science please click on: https://juniperpublishers.com/ajop/index.php

#Polymer Synthesis #polymer engineering #Ionomers #hydrogels

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pinoywhealth · 4 years

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Anion exchange membrane (AEM) fuel cells (AEMFCs), which produce electricity using hydrogen, are considered an alternative to currently used proton exchange membrane fuel cells. However, AEMs have problems with stability in alkaline conditions, which can be overcome by...

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cipherneutron · 5 months

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AEM Hydrogen Production: Innovative Solutions for Sustainable Energy

In the hunt for a clean energy future, AEM hydrogen production has quickly become an exciting technology that is coming forth and providing novel answers to the ever-rising sustainable energy challenges.

Powering the process with AEM electrolysers supports the use of water for the production of hydrogen gas, a fuel that is the future of clean atomization due to its versatile nature and the transition toward a carbon-free economy.

In contrast to the high-cost and unplentiful materials envisioned for traditional alkaline and proton exchange membrane (PEM) electrolysers, Anion Exchange Membrane systems operate more in an alkaline environment, cutting the need for these costly and scarce materials.

The AEM technology has generated massive improvement in the areas of efficiency, durability, and affordability, and this has, in the end, braced the change coming from the renewable energy sector. The pioneers in this field are constantly creating new breakthroughs as they perfect their products to meet the rising demands of power, quality, efficiency, and resilience.

While the planet strives to overcome the difficulties of climate change, the AEM electrolysers represent not only an exciting novelty but also a completely new approach to the generation and use of this clean energy resource. Explore the intricacies of this transformative technology at https://www.cipherneutron.com/the-aem-electrolyser/ and join the course toward a sustainable future.

#Anion Exchange Membrane #AEM electrolysers #AEM hydrogen production

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cooldavidkentposts · 4 years

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ARENA funds renewable methane demo plant

A $2.2 million project will see construction of a demonstration renewable methane plant to assess the benefits of using methane to ‘green’ Australia’s gas networks.

The Australian Renewable Energy Agency (ARENA) has announced $1.1 million in funding to APA Group to build the demonstration plant at the latter’s Wallumbilla Gas hub in Queensland, with the aim of generating cost and technical data to be used to assess the feasibility of a larger, commercial-scale, renewable methane plant.

It is expected that the ‘power to gas’ demonstration plant will produce approximately 620 kg of hydrogen per year, converting it into 74 GJ of methane that can then be injected into APA’s natural gas pipelines across the East Coast Gas Grid.

Renewable methane could enable the decarbonisation of Australia’s existing gas infrastructure, including gas transmission and distribution networks and export supply chains.

The renewable methane process involves the production of renewable hydrogen from an anion exchange membrane (AEM) electrolyser. The electrolyser uses water extracted from the atmosphere and is powered by solar PV. The hydrogen produced is then converted to methane by reaction with carbon dioxide, which is also extracted directly from the atmosphere.

“Renewable methane is in effect indistinguishable from the methane that currently fills our natural gas pipelines,” ARENA CEO Darren Miller said.

“The gas network is expected to play a key role in supporting the decarbonisation of Australia’s energy system.

“This project will demonstrate the viability of producing renewable methane from solar power. Through a new and innovative approach, the project will capture moisture in the air to produce renewable hydrogen as a precursor to renewable methane.

“At scale, renewable methane has the potential to be a significant source of Australia’s future natural gas requirements all through the deployment of solar energy and capturing the water from the atmosphere. Renewable methane is compatible with Australia’s developing hydrogen sector in that known technologies can convert methane to hydrogen and vice versa,” he said.

APA Group’s CEO and Managing Director, Rob Wheals, said, “ARENA’s support means we can work to understand the costs and benefits of generating renewable methane for use in the existing East Coast Gas Grid. This is a great example of government support for innovation in the Australian energy industry. APA is excited about its part in this process.

“We know the science of producing methane. This unique project is the first step in testing whether it is possible on an industrial scale to create methane using solar-generated electricity, water and CO2 from the atmosphere.

“With this project we’re aiming to determine whether this carbon-neutral process might be part of the green energy solution of the future, and if our pipelines can be used to transport pure renewable energy domestically or to be exported,” Wheals said.

source http://sustainabilitymatters.net.au/content/energy/news/arena-funds-renewable-methane-demo-plant-369706558

from WordPress https://davidkent.home.blog/2020/05/11/arena-funds-renewable-methane-demo-plant/

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heanjiaalloys · 6 years

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Mesh Cathode- Ideal for recovery & production of copper

The use of metals in today’s world and their improper disposal has created numerous environmental problems including toxicity due to uncontrolled metal leaching. It is very energy intensive to recover metal from contaminated soil or incineration ash leachates by methods such as electrowinning although the contaminated sites contain amounts comparable to some workable ores. The examination of Microbial Fuel Cells (MFCs) was done and deemed viable for energy-efficient recovery of metals from wastewater. The objective of this study was to upscale previous viability studies of copper recovery with ml-scale cells from highly acidic leachate to a litre-scale reactor. In addition, the investigation of the operation and control measures necessary for this type of MFC was done. The media used for a carbon felt anode were the synthetic medium and municipal wastewater amended with NaHCO3 and NaCH3COO. A titanium cathode was fed with a simulated leachate medium containing NaCl, HCl and CuSO4. The Anion Exchange Membrane (AEM) was the separator between them. Diffusion of ions through the AEM was tested in a small scale abiotic reactor in addition to investigating operation and control of both reactor chambers. The results showed steady start-up and stable performance of the MFC under controlled conditions however unfavorable conditions decreased the performance very rapidly. Controlling the pH in the cathode and anode chambers was the most challenging aspect in the operation of the reactor. The precipitation of copper e.g. Cu(OH)2 was done by high cathode Ph and the acid leaked into the anode chamber inhibiting efficient bioelectrochemical activity due to low pH. In addition, the anode was susceptible to very high bicarbonate concentration. Furthermore, the reactor, especially the anode had high voltage losses associated with mass transfer suggesting need for improvement in design and operation. The cathode was under-sized substantially and the current density was consequently increased to achieve the copper recovery. On the other hand, the maximum current density achievable was limited due to the decrease of cathode potential with decreasing cathode size. An important aspect to reduce mass transfer losses was the recirculation of the catholyte. A positive effect was put on the total cell voltage by the membrane potential across the AEM. Completely developed and optimized bio-anodes and titanium cathode with adequate current density over 1 A/m2 were successfully able to achieve sustainable copper recovery.

Another work was done with the objective to produce electrolytic copper powders by both electrorefining and electrowinning techniques in a new mesh cathode basket. Different cathode materials such as Stainless steel, Aluminum and Copper in the form of baskets were subjected to pure lead anodes for electrowinning process and pure or industrial Copper anode plates for electrorefining process. The most preferable basket material for deposition of copper powder using both electrowinning and electrorefining techniques was the Aluminum cathode basket. The contamination of Copper powder with Aluminum after a long period of electrolysis process was the major drawback of Aluminum basket. As per the indication from the scanning electron microscope analysis, pure and fine copper powders with dispersive shapes from electrorefining process and dendritic shape from electrowinning process were obtained.

#mesh electrode #mesh cathode #shaping nickel superalloys #aluminum

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