elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Exploitation of thermochemical cycles based on solid oxide redox systems for thermochemical storage of solar heat. Part 4: Screening of oxides for use in cascaded thermochemical storage concepts

Agrafiotis, Christos and Roeb, Martin and Sattler, Christian (2016) Exploitation of thermochemical cycles based on solid oxide redox systems for thermochemical storage of solar heat. Part 4: Screening of oxides for use in cascaded thermochemical storage concepts. Solar Energy, 139, pp. 695-710. Elsevier. DOI: 10.1016/j.solener.2016.04.034 ISSN 0038-092X

[img] PDF (Paper) - Registered users only
3MB

Official URL: http://ac.els-cdn.com/S0038092X16300676/1-s2.0-S0038092X16300676-main.pdf?_tid=2616c35c-b0b5-11e6-ba86-00000aacb362&acdnat=1479820455_4bc038ec2518bff8a8a2b959b078d949

Abstract

Air-operated Solar Tower Power Plants store the excess solar energy during on-sun operation as sensible heat in porous solid materials that function as recuperators during off-sun operation. Their storage capacity can be extended by coating or manufacturing the porous heat exchange modules with oxides of multivalent metals undergoing reduction/oxidation (redox) reactions accompanied by significant heat effects (e.g. Co3O4/CoO, BaO2/BaO, Mn2O3/Mn3O4, CuO/Cu2O). Furthermore, to maximize the amount of redox material that can be thermochemically exploited efficiently in a given thermochemical reactor volume, the idea of employing cascades of porous structures, incorporating different redox oxide materials and distributed in a certain rational pattern in space tailored to their thermochemical characteristics and the local temperature of the heat transfer medium is set forth. Thermogravimetric analysis studies with the oxides above were performed to identify the most suitable ones for further cascaded operation. The Co3O4/CoO redox pair has been already proven capable of stoichiometric, long-term, cyclic reduction–oxidation under a variety of conditions. The Mn3O4/Mn2O3 redox pair was found herein to be characterized by a large ‘‘temperature gap” between reduction (�940 �C) and oxidation (�780–690 �C) temperature, whereas the CuO/Cu2O and BaO2/BaO pairs could not work reproducibly and quantitatively. Thermal cycling tests with the Co3O4/CoO and Mn3O4/Mn2O3 powders operating together under the conditions required for complete oxidation of the less ‘‘robust” Mn3O4/Mn2O3, demonstrated that both powders can be reduced and oxidized in complementary temperature ranges, extending thus the temperature operation window of the whole storage cascade.

Item URL in elib:https://elib.dlr.de/108196/
Document Type:Article
Title:Exploitation of thermochemical cycles based on solid oxide redox systems for thermochemical storage of solar heat. Part 4: Screening of oxides for use in cascaded thermochemical storage concepts
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Agrafiotis, ChristosChristos.Agrafiotis (at) dlr.deUNSPECIFIED
Roeb, MartinMartin.Roeb (at) dlr.deUNSPECIFIED
Sattler, ChristianChristian.Sattler (at) dlr.dehttps://orcid.org/0000-0002-4314-1124
Date:1 December 2016
Journal or Publication Title:Solar Energy
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:139
DOI :10.1016/j.solener.2016.04.034
Page Range:pp. 695-710
Publisher:Elsevier
ISSN:0038-092X
Status:Published
Keywords:Solar energy, cascaded thermochemical heat storage, Redox pair oxides
HGF - Research field:Energy
HGF - Program:Renewable Energies
HGF - Program Themes:Solar Fuels
DLR - Research area:Energy
DLR - Program:E SF - Solar research
DLR - Research theme (Project):E - Solar Fuels (old)
Location: Köln-Porz
Institutes and Institutions:Institute of Solar Research > Solare Verfahrenstechnik
Deposited By: Sattler, Prof. Dr. Christian
Deposited On:24 Nov 2016 15:08
Last Modified:24 Nov 2016 15:08

Repository Staff Only: item control page

Browse
Search
Help & Contact
Information
electronic library is running on EPrints 3.3.12
Copyright © 2008-2017 German Aerospace Center (DLR). All rights reserved.