Contribution of pressure on performances of high temperature steam electrolysis cell
Creators
- Cacciuttolo, Quentin
- Universite Pierre et Marie Curie, Ecole doctorale de chimie physique et analytique de Paris centre - ED 388, IRCP - UMR 8247 - Equipe Interface, Electrochimie, Energie (France)
- Commissariat a l'energie atomique et aux energies alternatives - CEA Grenoble, projet Aphrodite (France)
- CEA Le Ripault, projet Aphrodite (France)
Description
In order to improve the industrial attractiveness of high temperature steam electrolysis (HTSE), the increase in the operating pressure is one of the most promising solutions. In this context, this study is dedicated to the analysis of the pressure influence on the electrochemical reactions occurring in HTSE. A Model and experimental results dealing with the effect of pressure increase have been carried out. Concerning the cathodic side model, the limiting current density due to the lack of steam is shifted towards higher steam conversion rates by increasing the operating pressure. Regarding the anodic side, a negative thermodynamic effect is predicted by Nernst equation but no negative effect appears at high current density. Furthermore, the overpressure at the oxygen electrode decreases with the operating pressure (and so the risk of delamination is reduced). At the same time, experimental studies on three electrodes cell until 30 bars have been lead on the oxygen electrode. A positive effect of the pressure on the oxygen side performances has been observed. This gain in performance could be explained by three different mechanisms. The mechanic effect of pressure increase contact inside the electrode. Furthermore, high pressure improves gas circulation and adsorption/desorption kinetics at the surface of electrode. (author)
Abstract (French)
L'electrolyse de l'eau a haute temperature permet de produire de l'hydrogene et de l'oxygene a partir d'eau, d'electricite et de chaleur grace a une cellule electrochimique en ceramique. Le travail sous pression est etudie afin d'eviter une etape de pressurisation du gaz necessaire au stockage de celui-ci. Un autoclave fonctionnant jusqu'a 850 deg. C et 30 bar a ete concu et deux modeles de demi-cellule representant respectivement l'electrode a hydrogene et l'electrode a oxygene ont ete developpes pour cette etude. Le modele a montre que la pression aide l'approvisionnement en vapeur d'eau jusqu'aux sites reactionnels. Les taux de conversion de la vapeur en hydrogene atteignent plus de 95 % a partir de 5 bar. Le modele du cote oxygene montre un effet thermodynamique negatif de la pression qui est predit par l'equation de Nernst. Il permet d'etudier les surpressions a l'interieur de l'electrode et donc le risque de delamination de l'electrode. Le travail sous pression permet de reduire ce risque en diminuant de 96 % les surpressions entre 1 et 30 bar. Le banc a permis d'etudier experimentalement l'electrode a oxygene grace a un montage a trois electrodes. Ses performances sont ameliorees avec la pression, ce qui permet de compenser l'effet thermodynamique negatif. Les gains de performance s'expliquent par l'effet mecanique de la pression, permettant d'ameliorer les contacts au sein de l'electrode mais aussi par une amelioration de la circulation de gaz et une amelioration de la cinetique des reactions d'adsorption/desorption a la surface de l'electrode. (auteur)
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Additional details
Additional titles
- Original title (French)
- Apport de la pression sur les performances d'une cellule d'electrolyse de la vapeur d'eau a haute temperature
Publishing Information
- Imprint Pagination
- 226 p.
- Report number
- FRCEA-TH--13157
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 52053992
- Subject category
- S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- ADSORPTION; CHEMICAL REACTION KINETICS; CURRENT DENSITY; DESORPTION; ELECTRODES; ELECTROLYSIS; HYDROGEN PRODUCTION; IONIC CONDUCTIVITY; PORE STRUCTURE; POROSITY; POTENTIOMETRY; PRESSURE DEPENDENCE; WATER VAPOR
- Descriptors DEC
- CHEMICAL ANALYSIS; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; FLUIDS; GASES; KINETICS; LYSIS; MICROSTRUCTURE; PHYSICAL PROPERTIES; QUANTITATIVE CHEMICAL ANALYSIS; REACTION KINETICS; SORPTION; TITRATION; VAPORS; VOLUMETRIC ANALYSIS
Optional Information
- Notes
- 149 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses