Proceedings of the International Renewable Energy Storage Conference 2021 (IRES 2021)

Experimental Investigation of the Cycle Stability of different Iron Oxide Composites for a Redox Hydrogen Storage Process

Authors
Lea Huber1, ORCID, Bernd Gamisch1, ORCID, Belal Dawoud1, *, ORCID
1Laboratory of Sorption Processes, Technical University of Applied Sciences Regensburg, Germany
*Corresponding author. Email: belal.dawoud@oth-r.de
Corresponding Author
Belal Dawoud
Available Online 3 March 2022.
DOI
https://doi.org/10.2991/ahe.k.220301.013How to use a DOI?
Keywords
Hydrogen Storage; Iron/Iron Oxide; Redox Reactions; Cycle Stability
Abstract

A promising process to store hydrogen is the thermochemical storage based on the repeated reduction and oxidation (redox) of iron oxide or iron. This storage process is an intermittent, two-phase reaction, which takes place under atmospheric pressure in a hydrogen atmosphere during reduction (charging) or in a steam atmosphere during oxidization (discharging). The investigations have been carried out at two constant temperatures, namely 700°C and 800°C. During the storage phase, only iron exists inside the storage reactor - a fact that makes the redox system much safer, compared to hydrogen storage under pressure in a tank.

This work aims at studying the effect of adding different supporting materials upon producing the iron oxide storage composite samples on their thermochemical cycle stability. Furthermore, the influence of the temperature during the initial sintering process and the redox cycles on the reaction behavior of the iron oxide composites is investigated.

It turned out that pure iron oxide pellets have lost about 65% of their redox potential after only three cycles. Applying 10 wt.% of calcium oxide has improved the cycle stability of the iron oxide pellets to over nine cycles. After nine cycles, a loss of redox performance by less than 5% was observed. This has been attributed to the densification of the sample’s outer surface, which is associated with slowing down the gas diffusion rate into/out of the investigated sample. In addition, reducing the temperature during the cycling (800°C to 700°C) and the sintering from 1100°C to 950°C has shown a positive effect on enhancing the cycle stability.

Copyright
© 2022 The Authors. Published by Atlantis Press International B.V.
Open Access
This is an open access article under the CC BY-NC license.

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Volume Title
Proceedings of the International Renewable Energy Storage Conference 2021 (IRES 2021)
Series
Atlantis Highlights in Engineering
Publication Date
3 March 2022
ISBN
978-94-6239-546-6
ISSN
2589-4943
DOI
https://doi.org/10.2991/ahe.k.220301.013How to use a DOI?
Copyright
© 2022 The Authors. Published by Atlantis Press International B.V.
Open Access
This is an open access article under the CC BY-NC license.

Cite this article

TY  - CONF
AU  - Lea Huber
AU  - Bernd Gamisch
AU  - Belal Dawoud
PY  - 2022
DA  - 2022/03/03
TI  - Experimental Investigation of the Cycle Stability of different Iron Oxide Composites for a Redox Hydrogen Storage Process
BT  - Proceedings of the International Renewable Energy Storage Conference 2021 (IRES 2021)
PB  - Atlantis Press
SP  - 126
EP  - 135
SN  - 2589-4943
UR  - https://doi.org/10.2991/ahe.k.220301.013
DO  - https://doi.org/10.2991/ahe.k.220301.013
ID  - Huber2022
ER  -