An experimental study is under way to assess the performance of solidoxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900c. Integrated laboratory scale operational 82207 720 cells, 3 modules 2008 46,080 cm2. In this cell the anode is carbon and the cathode is iron. We report on a thermodynamic analysis for water electrolysis from normal conditions p 0. Hightemperature electrolysis also called steam electrolysis is the water electrolysis at temperatures that. The cell voltage during electrolysis operation at a current density of. Kazimi massachusetts institute of technology, center for advanced nuclear. However the output of gas per coulomb and the heating effect are both decreased. High temperature electrolysis is under development and will be more efficient hte experimental results from 25cell stack and 2x60cell halfmodule, fabricated by ceramatec, hydrogen production rates in excess of 160 normal litershour were maintained with a 25cell solidoxide electrolysis stack for hours. High temperature and pressure alkaline electrolysis.
Directly coupled to hightemperature gascooled reactor for electrical power and process heat 600 mwth reactor could produce 85 million scfd 2. Allothermal process is a process where soec operate below the thermoneutral voltage 1. Hydrogen production using hightemperature steam hightemperature. Thermodynamics of hightemperature, highpressure water. Hoffman apparatus is used to demonstrate the electrolysis of water, alternatively, a power source and electrodes can show the same demonstration in a petri dish. A longterm test run over 2000 h with a steam content of 43% at 800 c and a current density of. Hightemperature solid oxide electrolysis cells soecs are advanced electrochemical energy storage and conversion devices with high conversionenergy efficiencies.
High temperature electrolysis is more efficient economically than traditional room temperature electrolysis. The inl high temperature electrolysis project history and background inl served as the lead laboratory for high temperature electrolysis hte research and development from 2003 2009, under the doe nuclear hydrogen initiative nhi during fy09, hte was selected by. High temperature solid oxide electrolysis cells soecs are advanced electrochemical energy storage and conversion devices with high conversionenergy efficiencies. High temperature electrochemistry the search for breakthroughs in electrolysis sossina m. Lowtemperature electrolysis operates at around 70 degrees to 100 degrees celsius and is already commercially available, but process efficiency is only 6080 percent. High temperature and pressure electrochemical test station. In addition, due to the chemical flexibility of those devices, it has been demonstrated that they could be used for the electrolysis of co 2 to co, and also for the coelectrolysis of h 2 o.
High temperature and pressure alkaline electrolysis dtu orbit. Aalborg universitet technology data for high temperature. Recent advances in high temperature electrolysis using solid. Department of energy hight electrolysis balance of plant 1025 2. Provisions are allowed to accommodate elevated operating temperature. In this case, the reactions that take place in both electrodes are. With steam you can typically achieve 20% higher efficiency with steam than with low temperature water. High temperature electrolysis hte hydrogen production. This report is aimed at addressing oxygen handling in a hte plant though oxygen itself is not flammable, most engineering material, including many gases and liquids. The electrical energy cost used in the calculations 1.
High temperature electrolysis is more efficient economically than traditional room temperature electrolysis because some of the energy is supplied as heat, which is cheaper than electricity, and because the electrolysis reaction is more efficient at higher temperatures. The first strategy a operates an electrolysis cell in a pressurized state by running feedwater through a pump. Also, high temperature electrolysis is more efficient economically than it would be at room temperature. The inl high temperature electrolysis project history and background inl served as the lead laboratory for high temperature electrolysis hte research and development from 2003 2009, under the doe nuclear hydrogen initiative nhi during fy09, hte was selected by doe as the primary nuclear hydrogen. The efficiency of electrolysis increases with the temperature as the hydrogen bonding reduces 1876. The researchers generated the 750 degrees celsius steam required for electrolysis by exploiting solar heat and the heat of the hightemperature electrolysis unit. Hydrogen production by hightemperature steam electrolysis. They offer attractive hightemperature coelectrolysis routes that reduce extra co2 emissions, enable largescale energy storageconversion and.
Develop innovative, cost effective and efficient protonconducting solid oxide electrolysis cells h soecs for largescale hydrogen production at intermediate temperatures 600800c. High temperature electrolysis cell soec electrolysis is a wellknown process to split water h 2o into hydrogen h 2 and oxygen o 2 by using electrical energy. Oxygen handling and cooling options in high temperature. Electrochemistry is the study of reactions in which charged particles ions or electrons cross the interface between two phases of matter, typically a metallic phase the electrode and a conductive solution, or electrolyte. Effect of temperature on the voltage of the electrolytic cell the figures 2, 3 and 4 show the effect of temperature on the cell voltage at different currents. High temperature alkaline electrolysis cells with metal foam based gas diffusion.
Recently, high temperature solid oxide electrolysis cells soecs have been actively investigated as a next generation electrolysis system that can achieve even higher energyconversion efficiency. Hightemperature electrolysis for hydrogen production materials 1 coordinate with the experimental work at ineel that will demonstrate the improvements in performance for a hightemperature steam electrolysis system operating at up to 1,000 k and assure that the data required to conduct a detailed. A process of this kind is known generally as an electrode process. High temperature alkaline electrolysis cells with metal. High temperature coelectrolysis of steam and co2 in an. High temperature water electrolysis using metal supported. Highpressure electrolysis hpe is the electrolysis of water by decomposition of water h 2 o into oxygen o 2 and hydrogen gas h 2 due to the passing of an electric current through the water. Electrolysis of molten nacl an example of this type of reaction is the electrolysis of molten sodium chloride. Hightemperature electrolysis during electrolysis, the amount of electrical energy that must be added equals the change in gibbs. Herring aiche 2007 11707 24 conclusions conventional electrolysis is available today high temperature electrolysis is under development and will be more efficient hte experimental results from 25cell stack and 2x60cell halfmodule, fabricated by ceramatec, hydrogen production rates in excess of 160 normal litershour were maintained with a 25cell solidoxide electrolysis.
Finally, the reversible voltage e r of the electrolysis of any reactant gas is e r dg n e. Aalborg universitet technology data for high temperature solid. The second b operates an electrolysis cell at atmospheric pressure with subsequent mechanical compression of product gases including the oxygen. Hightemp electrolysis combines with solarthermal steam. This report is aimed at addressing oxygen handling in a hte plant though oxygen itself is not flammable, most engineering material, including many gases and liquids, will burn in. The price for h 2 production at o c taken from table 1 is 4. An approach to try and combine the pros of the three main water electrolysis technologies is to take an alkaline electrolysis cell and increase the operating temperature from around 80c to 150.
Hightemperature electrolysis laboratory at inl smallscale experiments. Jul 01, 2008 idaho national laboratory is working on a project to generate hydrogen by high temperature electrolysis hte. This presentation does not contain any proprietary, confidential, or otherwise restricted information. Theory of water electrolysis the electrolysis of water is considered a wellknown principle to produce oxygen and hydrogen gas. F3036 journal of the electrochemical society, 163 11 f3036f3040 2016 jes focus issue on electrolysis for increased renewable energy penetration high temperature alkaline electrolysis cells with metal foam based gas diffusion electrodes c. Pdf in this paper, we report our design of high temperature electrolysis plant system and the analysis results. High temperature electrolysis using sofc cells were presented as a promising alternative to the existing water electrolysis methods for hydrogen production. Idaho national laboratory is working on a project to generate hydrogen by high temperature electrolysis hte. The researchers generated the 750 degrees celsius steam required for electrolysis by exploiting solar heat and the heat of the high temperature electrolysis unit. Determination of an equivalent mass by electrolysis 1. High temperature electrolysis htel or soel the figure 2 shows the fundamental principle for electrolysis cell.
Basically, the principle of a water electrolyser is to convert water and dc. Electrolysis technology alkaline electrolysis membrane electrolysis high temperature electrolysis anode reaction. It is the process by which a redox reaction is forced to take place by the passage of a direct electric current through an electrolyte in the molten or in aqueous solution. Longterm electrolysis tests were performed by monitoring the cell voltage as a function of time. This chapter focuses on hydrogen production through a breakthrough process, hightemperature steam electrolysis. In such an hte system, safety precautions need to be taken to handle high temperature oxygen at 830c. May 21, 2018 low temperature electrolysis operates at around 70 degrees to 100 degrees celsius and is already commercially available, but process efficiency is only 6080 percent.
High temperature water electrolysis using metal supported solid oxide electrolyser cells soec article pdf available in journal of applied electrochemistry 722010. In conventional electrolyzers, oxygen produced from electrolysis is usually released in the air stream. High temperature, high pressure electrolysis giner, inc cortney mittelsteadt. The difference with a standard proton exchange membrane electrolyzer is the compressed hydrogen output around 1220 megapascals 120200 bar 2. High efficiency steam electrolyzer aiquoc pham lawrence livermore national laboratory 7000 east avenue, l350, livermore, ca 94550 abstract a novel steam electrolyzer has been developed.
Recent advances in high temperature electrolysis using. High efficiency that increase with temperature see figure 8, especially when allothermal process is used. Perspective of high temperature electrolysis using soec. The operating temperature was 800 c for longterm tests and varied between 750 and. Nuclear power has significant excess generating capacity. Hefat2014 10th international conference on heat transfer, fluid mechanics and thermodynamics 14 16 july 2014 orlando, florida high temperature electrolysis, brayton power cycle and methanol production vujicic r. Oct 23, 2015 it increases the efficiency of the electrolysis reactionprocess. It increases the efficiency of the electrolysis reactionprocess. High temperature electrolysis is more efficient economically than traditional roomtemperature electrolysis because some of the energy is supplied as heat, which is cheaper than electricity, and also because the electrolysis reaction is more efficient at higher temperatures. In addition, due to the chemical flexibility of those devices, it has been demonstrated that they could be used for the electrolysis of co 2 to co, and also for the co electrolysis of h 2 o. Water electrolysis cost feedstock costs electricity consists of 50% of total cost. Introduction to electrolysis electrolytes and nonelectrolytes electrolysis is the process of electrically inducing chemical changes in a conducting melt or solution e. Electrolysis of aqueous solutions is complicated since water can be oxidized and reduced in addition to or instead of the ions present in solution.
In an electrolysis cell similar to the one employed in this experiment, a student observed that his unknown metal anode lost 0. What effect does temperature have on electrolysis of an. History water electrolysis to produce hydrogen and oxygen gases is a wellknown established process. Production of synthesis gas by hightemperature electrolysis of h. Thermoneutral and reversible potentials are determined using equationsofstate published by the international association for the properties of water and steam and the national institute of standards and. When a high voltage is applied to an electrochemical cell in presence of water, hydrogen and oxygen gas bubbles evolve at cathode negative electrode. Mogensen department of energy conversion and storage, technical university of denmark, frederiksborgvej 399. Proton conductor materials for high temperature steam electrolysis instead of using an oxygen conductor electrolyte, another possibility for soec is the use of a proton conductor.
Pdf hydrogen production by high temperature electrolysis with. High temperature electrolysis also hte or steam electrolysis is a technology for producing hydrogen from water at high temperatures. Pdf high temperature water electrolysis using metal. Key technical challenges for high temperature electrolysis. Theoretical maximum and potential future operation the advantage of the electrolysers is the possibility to choose the operation efficiency based on their polarization curves. Electrolysis reactions usually require quite a bit of energy. High temperature electrolysis for hydrogen production. Basic chemical reactions and operating temperature range for different types of water electro lysis 18. Review of scientific instruments 84, 054101 20 high temperature and pressure electrochemical test station c.
High temperature electrolysis cell soec electrolysis is a wellknown process to split water h 2 o into hydrogen h 2 and oxygen o 2 by using electrical energy. It presents the technology in general before detailing electrochemical reactions. Temperature is one of the most important variables in the electrolysis, because the efficiency increases with increasing the temperature 11, due. High temperature electrolysis for efficient hydrogen. The efficiency of electrolysers is inversely proportional to the cell voltage. This chapter focuses on hydrogen production through a breakthrough process, high temperature steam electrolysis. If the water can be converted into steam by waste heat from other processes it is more efficient to perform a high temperature electrolysis hte and convert the steam directly.
They offer attractive high temperature co electrolysis routes that reduce extra co 2 emissions, enable largescale energy storageconversion and facilitate the integration of. The general principle for all three technologies is the same. Advanced materials for elevated temperature water electrolysis. Information and opportunities for electric power utilities. Notes 50 electrolysis is a process during which a nonspontaneous redox reaction occurs when electrical energy is supplied. Temperature as a factor determining on water electrolysis. If the pressure over the electrolysis is increased then more current passes for the same applied voltage. Electrolysis is an electrochemical process in which electrical energy is the driving force of chemical. Hoffman apparatus dabney 125 dc power supply 1 m na 2so 4 alternative petri dish alternative. Determination of an equivalent mass by electrolysis. Therefore, adding the heat energy to the electrical energy increases the rate of reaction. In comparison to the conventional water electrolysis the high temperature electrolysis has few advantages such as. Dec 11, 2017 with steam you can typically achieve 20% higher efficiency with steam than with low temperature water.
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