Tesis sobre el tema "Alkaline Electrolysers"
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Serdaroglu, Gulcan. "Controlling the microstructure of the porous nickel electrodes in alkaline electrolysers". Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/49141/.
Texto completoKiaee, Mahdi. "Investigation of the cumulative impact of alkaline electrolysers on electrical power systems". Thesis, University of Strathclyde, 2016. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=26885.
Texto completoChade, Daniel Szymon. "Performance and reliability studies of Atmospheric Plasma Spraying Raney nickel electrodes for alkaline electrolysers". Thesis, University of Strathclyde, 2014. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25532.
Texto completoStemp, Michael C. "Homogeneous catalysis in alkaline water electrolysis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0019/MQ45844.pdf.
Texto completoLumanauw, Daniel. "Hydrogen bubble characterization in alkaline water electrolysis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0017/MQ54129.pdf.
Texto completoFiorentini, Diego. "Development of a polymeric diaphragm for Alkaline Water Electrolysis". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Buscar texto completoBradwell, David (David Johnathon). "Liquid metal batteries : ambipolar electrolysis and alkaline earth electroalloying cells". Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/62741.
Texto completoCataloged from PDF version of thesis.
Includes bibliographical references (p. 198-206).
Three novel forms of liquid metal batteries were conceived, studied, and operated, and their suitability for grid-scale energy storage applications was evaluated. A ZnlITe ambipolar electrolysis cell comprising ZnTe dissolved in molten ZnCl 2 at 500 0C was first investigated by two- and three-electrode electrochemical analysis techniques. The electrochemical behavior of the melt, thermodynamic properties, and kinetic properties were evaluated. A single cell battery was constructed, demonstrating for the first time the simultaneous extraction of two different liquid metals onto electrodes of opposite polarity. Although a low open circuit voltage and high material costs make this approach unsuitable for the intended application, it was found that this electrochemical phenomenon could be utilized in a new recycling process for bimetallic semiconductors. A second type of liquid metal battery was investigated that utilized the potential difference generated by metal alloys of different compositions. MgjlSb cells of this nature were operated at 700 °C, demonstrating that liquid Sb can serve as a positive electrode. Ca,MgIIBi cells also of this nature were studied and a Ca,Mg liquid alloy was successfully used as the negative electrode, permitting the use of Ca as the electroactive species. Thermodynamic and battery performance results suggest that Ca,MgIISb cells have the potential to achieve a sufficient cell voltage, utilize earth abundant materials, and meet the demanding cost and cycle-life requirements for use in grid-scale energy storage applications.
by David J. Bradwell.
Ph.D.
Davids, Wafeeq. "Consolidated Nanomaterials Synthesized using Nickel micro-wires and Carbon Nanotubes". Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_9685_1264387931.
Texto completoLaw, Joseph. "The role of vanadium as a homogeneous catalyst in alkaline water electrolysis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0020/MQ54216.pdf.
Texto completoHaug, Philipp [Verfasser]. "Experimental and theoretical investigation of gas purity in alkaline water electrolysis / Philipp Haug". München : Verlag Dr. Hut, 2019. http://d-nb.info/1181514061/34.
Texto completoSchmidt, Martin Jurgen. "Bubble phenomena in narrow gap electrolysis cells". Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322262.
Texto completoBoggs, Bryan Kenneth. "Improving Electrochemical Methods of Producing Hydrogen in Alkaline Media via Ammonia and Urea Electrolysis". Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1268668151.
Texto completoBateni, Fazel. "Development of Non-precious Metal and Metal Oxide Electrocatalysts for an Alkaline Lignin Electrolysis Process". Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1562674707447307.
Texto completoJia, Jingshu. "Fabrication of high quality one material anode and cathode for water electrolysis in alkaline solution /". View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?EVNG%202008%20JIA.
Texto completoDouglas, Tamunosaki Graham. "Development of an ambient temperature alkaline electrolyser for integrating with the electrical grid and renewable energy system". Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=19516.
Texto completoEspiritu, Richard. "Polyethylene-based anion exchange membrane for alkaline fuel cell and electrolyser application : synthesis, characterisation and degradation studies". Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3702.
Texto completoBoukarkour, Youness. "Étude de systèmes électro-catalytiques pour l’amélioration des performances de véhicules à moteurs thermiques". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0081.
Texto completoToday, the search for sustainable energy solutions has become a key concern due to the environmental crisis we are experiencing, with the transport sector among the most polluting areas due to the use of internal combustion engines (ICEs). While the transition to electric motors is underway, it will take time, as this equipment will not be accessible to everyone, and also has its own drawbacks. Therefore, despite current environmental policies, ICEs will still be around for a while. Logikko, the company we worked with, came up with the idea of supporting the energy transition by injecting H2 into ICEs. This injection, even in small quantities, can have a positive effect on pollutant emissions and on the engine itself, keeping it clean and efficient. To achieve this, it is necessary to produce hydrogen locally using an alkaline electrolyser that can be fitted under the hood of the vehicle. In this general context, the aim of my CIFRE thesis work was to improve the electrolysers developed by Logikko to make them more resistant to corrosion and also more energy efficient. Chapter 1 describes the concepts needed to understand the mechanisms of H2 production by alkaline electrolysis and the processes that govern them. We discuss the consequences of injecting this gas and the role it can play in reducing the pollutants emitted by the engine. In Chapter 2, we look at how the electrolyte used by the company can be optimised to reduce corrosion. Different electrode materials were studied using cyclic voltammetry and chronoamperometry. At the end of this chapter, we proposed two promising new electrode materials to the company. In the following chapter, we optimise the electrolyser by changing its design. To do this, we have delved into the principle of bipolar electrochemistry to identify the role of neutral plates and their impact on electrolyser efficiency. As a result of this study, we were able to further reduce the effects of corrosion and energy losses in the electrolyser. Pursuing our objective, in Chapter 4 we considered the application of an external magnetic field as a strategic innovation for inducing magnetohydrodynamic (MHD) effects. These can help increase electrolyser energy efficiency and hydrogen production, paving the way for innovative and economically viable applications. Finally, Chapter 5 describes related work we have been carrying out in parallel. These deal with the detection of Cr (VI) in the electrolyte after an operating time, as well as analytical methods using bipolar electrochemistry to rapidly and efficiently analyse the potential of alternative electrode materials for future developments
Zhang, Zhihao. "The Development of Three Dimensional Porous Nickel Materials and their Catalytic Performance towards Oxygen Evolution Reaction in Alkaline Media". Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40636.
Texto completoHaug, Philipp [Verfasser] y Thomas [Akademischer Betreuer] Turek. "Experimental and theoretical investigation of gas purity in alkaline water electrolysis / Philipp Haug ; Betreuer: Thomas Turek". Clausthal-Zellerfeld : Technische Universität Clausthal, 2019. http://d-nb.info/1231363312/34.
Texto completoWatkins, Luke. "Development of non-noble catalysts for hydrogen and oxygen evolution in alkaline polymer electrolyte membrane electrolysis". Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2296.
Texto completoPalaniappan, Ramasamy. "Improving The Efficiency Of Ammonia Electrolysis For Hydrogen Production". Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1386341476.
Texto completoJiang, Tao. "Development of Alkaline Electrolyzer Electrodes and Their Characterization in Overall Water Splitting". Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCA006.
Texto completoSplitting water into hydrogen and oxygen by electrolysis using electricity from intermittent ocean current, wind, or solar energies is one of the easiest and cleanest routes for high-purity hydrogen production and an effective way to store the excess electrical power without leaving any carbon footprints. The key dilemma for efficient large-scale production of hydrogen by splitting of water via the hydrogen and oxygen evolution reactions is the high overpotential required, especially for the oxygen evolution reaction. Hence, engineering highly active and stable earth-abundant oxygen evolution electrocatalysts with three-dimensional hierarchical porous architecture via facile, effective and commercial means is the main objective of the present PhD study. Finally, we developed two kinds of good performance oxygen evolution electrocatalysts through two different way combined with in situ electrochemical activation.For the first oxygen evolution electrocatalyst, we report a codoped nickel foam by nickel crystals, tricobalt tetroxide nanoparticles, graphene oxide nanosheets, and in situ generated nickel hydroxide and nickel oxyhydroxide nanoflakes via facile electrolytic codeposition in combination with in situ electrochemical activation as a promising electrocatalyst for oxygen evolution reaction. Notably, this hybrid catalyst shows good electrocatalytic performance, which is comparable to the state-of-the-art noble catalysts. The hybrid catalyst as an electrocatalytically-active and robust oxygen evolution electrocatalyst also exhibits strong long-term electrochemical durability. Such a remarkable performance can be benefiting from the introduced active materials deposited on nickel foam, in situ generated nickel oxyhydroxide nanoflakes and their synergistic effects. It could potentially be implemented in large-scale water electrolysis systems.For the second oxygen evolution electrocatalyst, a facile and efficient means of combining high-velocity oxy-fuel spraying followed by chemical activation, and in situ electrochemical activation based on oxygen evolution reaction has been developed to obtain a promising self-supported oxygen evolution electrocatalyst with lattice-distorted Jamborite nanosheets in situ generated on the three-dimensional hierarchical porous framework. The catalyst developed in this work exhibits not only exceptionally low overpotential and Tafel slope, but also remarkable stability. Such a remarkable feature of this catalyst lies in the synergistic effect of the high intrinsic activity arising from the lattice-dislocated Jamborite nanosheets as the highly active substance, and the accelerated electron/ion transport associated with the hierarchical porous architecture. Notably, this novel methodology has the potential to produce large-size-electrode for alkaline water electrolyzer, which can provide new dimensions in design of highly active and stable self-supported electrocatalysts.Furthermore, we have also initially developed good hydrogen evolution electrocatalysts upon in situ electrochemical activation, coupled with the obtained superior oxygen evolution electrocatalysts forming two-electrode configurations, respectively, both of which rivalled the integrated state-of-the-art ruthenium dioxide-platinum electrode in alkaline overall water splitting.In summary, a methodology of fabricating easy-to-commercial, high performance catalytic electrodes by combining general coating processes with in situ electrochemical activation has been realized and well developed. The in situ electrochemical activation mentioned above is a dynamic self-optimization behavior which is facile, flexible, effective and eco-friendly, as a strategy of fabricating self-supported electrodes for efficient and durable overall water splitting. We hope our work can promote advanced development toward large-scale hydrogen production using excess electrical power whenever and wherever available
SIRACUSANO, STEFANIA. "Development and characterization of catalysts for electrolytic hydrogen production and chlor–alkali electrolysis cells". Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/1337.
Texto completoThe topics of this PhD thesis are concerning with Chlor alkali electrolysis and PEM water electrolysis. • Chlor alkali electrolysis. The industrial production of chlorine is today essentially achieved through sodium chloride electrolysis, with only a minor quantity coming from hydrochloric acid electrolysis. The main problem of all these processes is the high electric energy consumption which usually represents a substantial part of the total production cost. Therefore, in order to improve the process, it is necessary to reduce the power consumption. The substitution of the traditional hydrogen-evolving cathodes with an oxygen-consuming gas diffusion electrode (GDE) involves a new reaction that reduces the thermodynamic cell voltage and leads to an energy savings of 30-40%. My research activity was addressed to the investigation of the oxygen reduction at gas-diffusion electrodes as well as to the surface and morphology analysis of the electrocatalysts. Specific attention was focused on deactivation phenomena involving this type of GDE configuration. The catalysts used in this study were based on a mixture of micronized silver particles and PTFE binder. In this study, fresh gas diffusion electrodes were compared with electrodes tested at different times in a chlor-alkali cell. Electrode stability was investigated by life-time tests. The surface of the gas diffusion electrodes was analyzed for both fresh and used cathodes by scanning electron microscopy and X-ray photoelectron spectroscopy. The bulk of gas diffusion electrodes was investigated by X-ray diffraction and thermogravimetric analysis. • PEM water electrolysis. Water electrolysis is one of the few processes where hydrogen can be produced from renewable energy sources such as photovoltaic or wind energy without evolution of CO2. In particular, an SPE electrolyser is considered as a promising methodology for producing hydrogen as an alternative to the conventional alkaline water electrolysis. A PEM electrolyser possesses certain advantages compared with the classical alkaline process in terms of simplicity, high energy efficiency and specific production capacity. This system utilizes the well know technology of fuel cells based on proton conducting solid electrolytes. Unfortunately, electrochemical water splitting is associated with substantial energy loss, mainly due to the high over-potentials at the oxygen-evolving anode. It is therefore important to find the optimal oxygen-evolving electro-catalyst in order to minimize the energy loss. Typically, platinum is used at the cathode for the hydrogen evolution reaction (HER) and Ir or Ru oxides are used at the anode for the oxygen evolution reaction (OER). These metal oxides are required, compared to the metallic platinum, because they offer a high activity, a better long-term stability and less efficiency losses due to corrosion or poisoning. My work was mainly addressed to a) the synthesis and characterisation of IrO2 and RuO2 anodes; b) conducting Ti-suboxides support based on a high surface area. a) Nanosized IrO2 and RuO2 catalysts were prepared by using a colloidal process at 100°C; the resulting hydroxides were then calcined at various temperatures. The attention was focused on the effect of thermal treatments on the crystallographic structure and particle size of these catalysts and how these properties may influence the performance of oxygen evolution electrode. Electrochemical characterizations were carried out by polarization curves, impedance spectroscopy and chrono-amperometric measurements. b) A novel chemical route for the preparation of titanium suboxides (TinO2n−1) with Magneli phase was developed. The relevant characteristics of the materials were evaluated under operating conditions, in a solid polymer electrolyte (SPE) electrolyser, and compared to those of the commercial Ebonex®. The same IrO2 active phase was used in both systems as electrocatalyst.
Fan, Kaicai. "Development of High Performance Electrocatalyst for Water Splitting Application". Thesis, Griffith University, 2018. http://hdl.handle.net/10072/382229.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
Full Text
Bick, Daniel S. [Verfasser], Manfred [Akademischer Betreuer] Martin y Rainer [Akademischer Betreuer] Waser. "Performance and degradation of BaCoO$_3}$ based Perovskite catalysts during oxygen evolution in alkaline water electrolysis / Daniel Sebastian Bick ; Manfred Martin, Rainer Waser". Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1210862654/34.
Texto completoSundin, Camilla. "Environmental Assessment of Electrolyzers for Hydrogen Gas Production". Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-260069.
Texto completoVätgas har potential att spela en viktig roll som energibärare i framtiden med många användningsområden, såsom ett rent bränsle för transporter, uppvärmning, kraftförsörjning där elproduktion inte är lämpligt, med mera. Redan idag är vätgas ett viktigt inslag i flera industrier, där ibland raffinaderier och kemiska industrier. Det finns flera metoder för att producera vätgas, där reformering av naturgas är den största produktionsmetoden idag. I framtiden spås vätgasproduktion med elektrolys bli allt viktigare, då hållbara produktionsprocesser prioriteras allt mer. Idag används främst två elektrolysörtekniker, alkalisk och polymerelektrolyt. Utöver dessa är högtemperaturelektrolysörer också intressanta tekniker, där fastoxidelektrolysören är under utveckling och smältkarbonatelektrolysören är på forskningsstadium. I det här examensarbetet har en jämförande livscykelanalys utförts på alkalisk- och smältkarbonatelektrolysören. På grund av felaktiga indata för smältkarbonatelektrolysören har dessa resultat uteslutits från den publika rapporten. Miljöpåverkan från den alkaliska elektrolysören har sedan jämförts med miljöpåverkan från fastoxid- och polymerelektrolytelektrolysörerna. Systemgränserna sattes till vagga till grind. De livscykelsteg som inkluderats i studien är därmed råmaterialutvinning, elektrolysörtillverkning, vätgasproduktion och transporter mellan dessa steg. Den funktionella enheten valdes till 100 kg producerad vätgas. Resultaten visar att polymerelektrolytteknologin har den lägsta miljöpåverkan utav de tekniker som jämförts. Resultaten påvisar också att livstiden och strömtätheten för de olika teknikerna har signifikant påverkan på teknikernas miljöpåverkan. Dessutom fastslås att elektriciteten för vätgasproduktion har högst miljöpåverkan utav de studerade livscykelstegen. Därför är det viktigt att elektriciteten som används för vätgasproduktionen kommer ifrån förnybara källor.
Byrne, Philip. "Mathematical modelling and experimental simulation of chlorate and chlor-alkali cells". Doctoral thesis, Stockholm, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3182.
Texto completoKunovjánek, Miroslav. "Studium vodivosti PVA membrán, obsahujících alkalické hydroxidy". Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-234580.
Texto completoRodene, Dylan D. "Engineering of Earth-Abundant Electrochemical Catalysts". VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/6106.
Texto completoFeynerol, Vincent. "Traitement de minerais de fer par lixiviation alcaline suivi de leur électrolyse en milieu alcalin". Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0163.
Texto completoAn innovative ironmaking process by alkaline electrolysis of suspended iron oxides is being developed at ArcelorMittal Global R&D Maizières-lès-Metz. Were it to achieve industrial maturity, this process would permit a significant reduction of steelmaking CO2 emissions. Indeed, the use of carbon as a reducing agent in blast furnace would be replaced by electricity. Although this process enables iron production from commercial hematite (Fe2O3) at current density of 1000 A.m-2 with faradaic efficiency higher than 80%, these performances are systematically lower when using iron ore instead. The main impurities in these ores are aluminium and silicon oxides and hydroxides, these compounds are soluble in concentrated sodium hydroxide solutions. These compounds could be the source of the decrease in reactivity observed when feeding the process with iron ores. To raise the electrolysis performance with iron ores, alkaline leaching treatments were conducted on a defined iron ore. Reactivity of iron ores before and after treatment was compared by chronoamperometry. Although the elimination of aluminous compounds resulted in the ore gaining a faradaic yield increase to a value of 80%, compared with 65% before treatment, its current density remained twice as low as the one of hematite for a same applied voltage. Furthermore, complementary experiments of aluminate and silicate ions addition during pure hematite electrolysis did not have any deleterious effect on its electrolysis. Based on all the experiments undertaken in this PhD, it seems unlikely that siliceous and aluminous impurities hold an important effect on iron ore reactivity in alkaline electrolysis. The process is nonetheless very sensitive to iron ores granulometry. On this subject, strong agglomeration phenomena were witnessed when measuring iron ores granulometry but did not occur with pure iron oxides. Therefore, it would seem that other phenomena may be the main cause of reactivity loss, these phenomena may well be linked to secondary granulometry of iron ores in concentrated alkaline media. In parallel, an advanced thermodynamic analysis was carried out to describe the best theoretical conditions for pressure, temperature and NaOH concentration to realize hematite electrolysis. Gangue compounds solubility was represented with Pitzer equations, and new parameters were calculated for Na-SiO3-Al(OH)4 interactions. This thermodynamic study enabled the design and pre-sizing of a treatment step for iron ores by alkaline leaching
Feynerol, Vincent. "Traitement de minerais de fer par lixiviation alcaline suivi de leur électrolyse en milieu alcalin". Electronic Thesis or Diss., Université de Lorraine, 2018. http://www.theses.fr/2018LORR0163.
Texto completoAn innovative ironmaking process by alkaline electrolysis of suspended iron oxides is being developed at ArcelorMittal Global R&D Maizières-lès-Metz. Were it to achieve industrial maturity, this process would permit a significant reduction of steelmaking CO2 emissions. Indeed, the use of carbon as a reducing agent in blast furnace would be replaced by electricity. Although this process enables iron production from commercial hematite (Fe2O3) at current density of 1000 A.m-2 with faradaic efficiency higher than 80%, these performances are systematically lower when using iron ore instead. The main impurities in these ores are aluminium and silicon oxides and hydroxides, these compounds are soluble in concentrated sodium hydroxide solutions. These compounds could be the source of the decrease in reactivity observed when feeding the process with iron ores. To raise the electrolysis performance with iron ores, alkaline leaching treatments were conducted on a defined iron ore. Reactivity of iron ores before and after treatment was compared by chronoamperometry. Although the elimination of aluminous compounds resulted in the ore gaining a faradaic yield increase to a value of 80%, compared with 65% before treatment, its current density remained twice as low as the one of hematite for a same applied voltage. Furthermore, complementary experiments of aluminate and silicate ions addition during pure hematite electrolysis did not have any deleterious effect on its electrolysis. Based on all the experiments undertaken in this PhD, it seems unlikely that siliceous and aluminous impurities hold an important effect on iron ore reactivity in alkaline electrolysis. The process is nonetheless very sensitive to iron ores granulometry. On this subject, strong agglomeration phenomena were witnessed when measuring iron ores granulometry but did not occur with pure iron oxides. Therefore, it would seem that other phenomena may be the main cause of reactivity loss, these phenomena may well be linked to secondary granulometry of iron ores in concentrated alkaline media. In parallel, an advanced thermodynamic analysis was carried out to describe the best theoretical conditions for pressure, temperature and NaOH concentration to realize hematite electrolysis. Gangue compounds solubility was represented with Pitzer equations, and new parameters were calculated for Na-SiO3-Al(OH)4 interactions. This thermodynamic study enabled the design and pre-sizing of a treatment step for iron ores by alkaline leaching
Carnieletto, Renata. "Aproveitamento de energia vertida turbinável para produção de hudrogênio e geração distribuída". Universidade Federal de Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/8486.
Texto completoIn many hydroelectric power plants, while the water inflows are greater than demand, part of this water that could be used to generate energy is spilled by the dam gates and literally wasted. This dissertation discusses the use of this wasted hydroelectric potential for hydrogen (H2) generation through water electrolysis. The usage of this hydrogen can happen not only in vehicle engines or industrial applications, but in energy generation through fuel cells and behaving as an energy vector. The H2 production by electrolysis requires an energy source for its processing. This dissertation aims at to mitigate this issue by the use of the secondary energy. Besides the H2 generation aspects, it is presented the complete mathematic model of alkaline electrolyzers. With respect to the wasted hydroelectric potential approach it must be taken into account that alternative sources of energy are settled onto three bases: the energy source itself, the distribution grid and the interconnection energy source-to-grid (or source-to-load). Looking at this fact, the source connection and disconnection from the grid is a challenge for systems engineering. For this dissertation the simulation of Voltage Source Inverters (VSI) was selected to represent the islanded and grid tied conditions. For that, it is proposed an anti-islanding algorithm used to protect the system against faults that may occur in the grid. A reconnection algorithm is also included to obtain the synchronism of the alternative source with the electric grid. To control these inverters, two control techniques are presented along this text: DQ-frame and the proportional and resonant (P+Resonant) control. These control techniques are simulated to evaluate the application efficiency of such controllers. Additionally a smart control in perspectives of the smart grid was also developed and it is proposed in this dissertation. A smart grid integrated to the distribution system allows aggregation of efficient actions of all agents related to electricity services and so strategically making available the electricity goods and services. In this context, based on real-time spot pricing of the electricity obtained from the utility using an advanced metering device, the inverter control algorithm determines the optimal operating mode. This algorithm enables the inverter to: a) schedule local loads; b) determine either to local storage or selling of energy to the grid. Finally, it is shown that on-line fault detection in the system can also make possible a fast restoration of most contingence situations.
Em muitas Usinas Hidrelétricas, quando as afluências de água são maiores que a demanda, uma parcela desta água que ainda poderia ser utilizada para gerar energia é desviada para o vertedouro e literalmente desperdiçada. Esta energia recebe a denominação de Energia Vertida Turbinável (EVT). Essa dissertação discute o aproveitamento da EVT para produção de hidrogênio através da eletrólise da água. O uso desse hidrogênio pode ocorrer não apenas em motores de veículos ou aplicações industriais, mas na própria geração de energia elétrica em células a combustível, agindo como vetor energético. A produção de H2 por eletrólise da água convencionalmente necessita de uma fonte de energia para o processo. Essa dissertação sugere a mitigação deste problema pela utilização de energia secundária. Além de aspectos para produção de H2, é apresentada uma modelagem matemática completa de todo este processo envolvendo os eletrolisadores alcalinos. Na abordagem da EVT há que se levar em conta que as fontes alternativas em geral estão assentadas em três fundamentos: a fonte de energia, a rede de distribuição e a interconexão fonte de energia-rede (ou fonte-carga). Com vistas a este fato, a desconexão e re-conexão entre a fonte e a rede pode ser um problema desafiador para a engenharia de sistemas. Para esta dissertação, selecionou-se a simulação dos Inversores VSI (Voltage Source Inverters) como resposta para as condições de ilhamento e conexão à rede elétrica. Para isto, propõe-se um algoritmo anti-ilhamento que visa a proteção contra as faltas que possam ocorrer na rede e um algoritmo de re-conexão à rede, incluindo o meio de sincronismo da fonte alternativa com a rede. Para controlar tais inversores, duas técnicas são apresentadas ao longo deste texto: utilizando as transformações DQ e controle proporcional e ressonante (P+Resonant). Essas duas técnicas de controle são simuladas para se avaliar a eficiência da aplicação de tais controladores. Em adicional, foi desenvolvido um controle inteligente diferenciado com perspectivas ao Smart Grid. O Smart Grid integrado aos sistemas de distribuição permite agregar de forma eficiente as ações de todos os agentes ligados a ele para que, de forma estratégica, sejam disponibilizados bens e serviços de eletricidade. Neste contexto, o controle inteligente proposto para inversores de conexão com rede a utiliza técnicas de gerenciamento pelo lado da demanda e ainda determina automaticamente o ponto ótimo de operação do inversor, possibilitando assim o planejamento e arranjo de cargas locais e a determinação de quando deve ser armazenada energia ou vendida para a rede. Mostra-se finalmente que a detecção das falhas no sistema também poderá ser praticada de forma a se poder atuar rapidamente no restabelecimento das situações de contingência.
Gillespie, Malcolm Ivor. "Evaluation of performance influencing parameters on alkaline water electrolysis systems". Thesis, 2016. http://hdl.handle.net/10539/20024.
Texto completoHSIEH, WEN-HAO y 解文浩. "Fabrication of nanostructured electrodes via AAO templates for alkaline water electrolysis". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/84295272112523001373.
Texto completo南臺科技大學
光電工程系
104
In order to decrease the operating voltage and increase the efficiency of water electrolysis, we produced nanostructured materials as the electrodes. We electroplated nickel/platinum into the pores of anodic aluminum oxide (AAO) templates to form electrodes with high specific surface area which can increase the catalytic activity. The experimental procedures were as follows: using electron beam evaporator to deposit titanium film on glass substrate as the buffer layer, and nickel or gold strips on the buffer layer as the conducting layer; using thermal evaporator to deposit aluminum film on the conducting layer and then anodically oxidizing the aluminum film to form porous AAO; using chemical dissolution to remove barrier oxide to form barrier-free AAO template; using nickel aminosulfonate or hexachloroplatinic acid as the plating solution to electroplate nickel or platinum into the AAO pores. After removing the AAO, nickel nanopillar arrays or platinum nanopillar arrays were obtained. According to the experimental results, the quality of aluminum film influences the quality of AAO template significantly. After using two-step deposition, the surface property and crystallinity of aluminum film were highly improved. A high quality AAO template was successfully prepared. With this template, nickel nanopillar arrays or platinum nanopillar arrays with pillar diameter of 150~250 nm were electroplated, and the length of nanopillars could be adjusted by the plating time. The results of alkaline water electrolysis showed that the efficiency of hydrogen evolution and oxygen evolution were obviously increased by the nanopillar array electrodes. It also demonstrated that the platinum nanopillar electrode has higher catalytic activity than nickel nanopillar electrode in the process of cathodic hydrogen production, but lower catalytic activity in the process of anodic oxygen production. By analyzing the electrochemical characteristics of electrodes, we found that the thickness of conducting layer under the nanopillars affects the performance of water electrolysis. By increasing the thickness of conducting layer, the efficiency of water electrolysis using nanopillar-array electrodes can be further improved.
Huang, Da-Yun y 黃大勻. "The Study of the Zinc Flake Produced by Alkaline Electrolysis with Pulse". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/87427406755527683917.
Texto completo國立高雄應用科技大學
機械與精密工程研究所
102
In this research is to use alkaline electrolysis with the pulse current to produce zinc flake. Experimental reaction system equipment is 500ml, the processing via pre-experiment that choose the anode is stainless steel, the cathode is magnesium plate, the anode and cathode plates are processed through the grinding and polishing. In this experiment, 6M NaOH as the electrolyte, through to change frequency, duty ratio, voltage, zinc in the electrolyte concentration of 6M NaOH and cathode plate to experiment that which parameter can be produced zinc flake thickness from 0.1 to 0.3μm. Changing in the current frequency are respectively 50Hz, 60Hz, 70Hz, 80Hz, 90Hz, 100Hz and 250Hz. The frequency range from 50Hz to 100Hz is the lower of the frequency that the zinc grow slower of grain growth and smaller particle. The frequency range from 100Hz to 250Hz are the higher of the frequency that the zinc rapid grow grain growth, but easily to reunite and large power; The duty ratio of pulse setting are respectively 0.025, 0.1, 0.2, 0.5, 0.8, the duty ratio in 0.5 is the best in another parameters, because of less reunite. The duty ratio range from 0.025 to 0.2 has the larger of the zinc surface pores. Changing in the voltage are respectively 100V, 150V, 200V, 250V and 300V, the voltage range from 100V to 200V is the lower of the voltage that produce zinc slowly and small of the particle, but reunion caused from resistance. the voltage range from 200V to 300V is the higher of the voltage that produce zinc fast and thick of the particle; Zinc in the electrolyte concentration are respectively 4, 6, 8, 12, 18, 24, 30 and 36 g-Zn/L. Zinc concentration range from 12 to 36 g-Zn/L are the higher of the zinc concentration that the zinc grains grew larger and thick; Zinc concentration range from 4 to 12 g-Zn/L are the lower of the zinc concentration that the zinc grains grew small. When the zinc concentration below 6 g-Zn/L or less, due to the small grains of zinc binding ability, resulting in agglomeration and thick. Conditions for the optimal parameters can be learned from the experimental and data statistics, voltage is 200V, the duty ratio is 0.5, frequency is 50Hz, anode plate is stainless steel, cathode plate is magnesium plate, plates spacing are 90mm, zinc in the electrolyte concentration is 4 g-Zn/L, electrolysis time is 30min, producing zinc flake thickness is 0.3μm.
Cheng, Yi-Sheng y 鄭逸聖. "A Study on Recovery of Lead and Zinc from Strongly Alkaline Wastewaters by Electrolysis". Thesis, 1999. http://ndltd.ncl.edu.tw/handle/52765938753275416472.
Texto completo國立中山大學
環境工程研究所
87
The recovery of lead from strongly alkaline wastewaters by electrowining using an electrolytic cell of fluidized-bed type and subsequent recovery of zinc by an electrolytic cell of Cu-Zn cell─fluidized-bed type were investigated. The fluidized-bed medium was nonconductive glass beads of 0.5 mm in diameter. Sheets of stainless steel and lead were used for recovery of lead as the anode and cathode, respectively in the electrolytic cell of the fluidized-bed type. On the other hand, sheets of copper and zinc were used for recovery of zinc as the anode and cathode, respectively in the electrolytic cell of Cu-Zn cell─fluidized-bed type. For the study of electrolytic recovery of lead, the experiments were carried out based on 23 full factorial design using current density, surface area of electrode, and operating temperature as the experimental factors. For the study of electrolytic recovery of zinc, current density, surface area of electrode, and stirring were selected as the experimental factors. The electrolytes include : (1) synthetical solutions containing single metal of lead, (2) synthetical solutions containing lead and zinc, (3) simulated wastewaters for the synthesis of zeolites from two municipal incinerator fly ashes (designated MIFA S and MIFA T, respectively) , and the actual wastewaters due to the synthesis of zeolites from MIFA S and MIFA T. It was determined that operating at a lower current density and a larger surface area of electrode would result in a better recovery of lead, a lower energy consumption, and a better current efficiency. The effect of operating temperature, however, was found to be insignificant. For zinc, operating at a higher current density, a smaller surface area of electrode, and stirring would result in a better current efficiency and improve its removal efficiency. 97.98 % and 98.56 % of lead were recovered from the actual wastewaters due to the synthesis of zeolites from MIFA S and MIFA T when 1.44 Amp-hr and 1.68 Amp-hr were applied, respectively. The energy consumption for these two cases were determined to be 8.065 Kwh/Kg and 3.970 Kwh/Kg, respectively. On the other hand, 97.62 % and 97.37 % of zinc were recovered from the actual wastewaters due to the synthesis of zeolites from MIFA S and MIFA T when 4.8 Amp-hr were applied. The energy consumption for these two cases were determined to be 141.0 Kwh/Kg and 167.8 Kwh/Kg, respectively. Lead of 79.74 % and 88.81 % in purity and zinc of 96.53 % and 91.06 % in purity were recovered from the actual wastewaters due to the synthesis of zeolites from MIFA S and MIFA T, respectively.
Silva, João Fernando de Andrade Cardoso da. "Study of Dimensionally Stable Anodes for chlor-alkali electrolysis". Doctoral thesis, 2016. https://hdl.handle.net/10216/95969.
Texto completoSilva, João Fernando de Andrade Cardoso da. "Study of Dimensionally Stable Anodes for chlor-alkali electrolysis". Tese, 2016. https://hdl.handle.net/10216/95969.
Texto completoAzevedo, Daniela de Aguiar e. "Influence of the atmospheric plasma spray coating in electrodes properties to use in alkaline electrolysis". Master's thesis, 2017. https://hdl.handle.net/10216/106753.
Texto completoAzevedo, Daniela de Aguiar e. "Influence of the atmospheric plasma spray coating in electrodes properties to use in alkaline electrolysis". Dissertação, 2017. https://hdl.handle.net/10216/106753.
Texto completoWu, Wei-Hua y 伍偉華. "The analysis of efficiency on the acido-alkaline proton exchange membrane water electrolysis by using multi-electrode and pulse". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/g7q67b.
Texto completo國立中央大學
能源工程研究所
106
In this experiment, multiple sets of nickel electrodes were used to produce hydrogen by proton exchange membrane water electrolysis (PEMWE) under the action of pulses and potassium hydroxide and sulfuric acid electrolytes. The relevant data were measured by potentiostat, and effects of applied voltage, number of electrode groups,base potential and pulses on the efficiency were investigated. Results show that dual cells and electrolytes can reduce the electrolysis voltage to 0.7V, and improve the efficiency of hydrogen production. Multi-electrode reduces the overall resistance and impedance, thereby improves the energy efficiency. finally as the pulse is added, the instantaneous current value is increased, and the generating hydrogen gas deviates rapidly from the surface of the electrode, accelerates the diffusion speed of the ions, and reduces the polarization phenomenon on the electrode. The efficiency of hydrogen production is thus improved. As the electrode spacing is 10 mm, the acid and alkali concentration is 30% by weight, and the frequency is 100Hz, The energy efficiency at 4V is about 15% higher than no pulse is used. and five groups of electrodes at 2V have the best efficiency of 98.6%.
Wang, Li-Yeh y 王儷曄. "Preparation of Ru and Ir Films on the Ni Inverse Opal as Cathodes for Hydrogen Evolution Reaction in Alkaline Electrolysis". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/33620036419403396838.
Texto completo國立交通大學
材料科學與工程學系
98
The catalysts for hydrogen evolution reaction(HER)using Ru or Ir coated half-layer Ni inverse opal in 1 M KOH aqueous solution was investigated. RuO2 and IrO2 thin films were deposited by electroless plating and reduced subsequently to Ru and Ir at 200˚C under hydrogen treatment. The resulting electrode combined the advantage of large surface area and reasonable electro-catalytic activity. Variables such as deposition time, annealing temperature, and various annealing environments played critical roles. From SEM images, ICP-MASS and i-V polarization measurements, we determined the optimized processing condition. The reason is the surface area was decreased by the increased deposition time. According to the result of XRD and the thermal expansion coefficient of different materials on the substrate, the electro-catalytic activity was increased with the crystallinity but suffered from poor adhesion. Comparing both oxidative and metallic states of Ru and Ir films, we concluded that the metallic state revealed better catalytic ability.
Langels, Hanna y Oskar Syrjä. "Hydrogen Production and Storage Optimization based on Technical and Financial Conditions : A study of hydrogen strategies focusing on demand and integration of wind power". Thesis, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-435176.
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