Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Hydrogen reduction of iron ore pellets : A surface study using ambient pressure X-ray photoelectron spectroscopy

Heidari, Aidin ; Ghosalya, Manoj Kumar ; Alaoui Mansouri, Mohammed ; Heikkilä, Anne ; Iljana, Mikko ; Kokkonen, Esko LU orcid ; Huttula, Marko ; Fabritius, Timo and Urpelainen, Samuli LU (2024) In International Journal of Hydrogen Energy 83. p.148-161
Abstract

Using Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS), this study investigates the reduction behavior of iron oxides in direct reduction (DRI) and blast furnace (BF) pellets. H2, CO, and a H2–CO mixture are used as reducing agents at 650 °C. The investigation aimed to elucidate variations in the rate of reduction over time and under different conditions. Additionally, contour plots are generated to visualize the X-ray photoelectron peak intensity variations as a function of time. Furthermore, phase stability diagrams based on Fe–O–C and Fe–O–H systems are employed to enhance the understanding of reduction behavior. Results revealed that an increased gas flow rate significantly accelerated the reduction... (More)

Using Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS), this study investigates the reduction behavior of iron oxides in direct reduction (DRI) and blast furnace (BF) pellets. H2, CO, and a H2–CO mixture are used as reducing agents at 650 °C. The investigation aimed to elucidate variations in the rate of reduction over time and under different conditions. Additionally, contour plots are generated to visualize the X-ray photoelectron peak intensity variations as a function of time. Furthermore, phase stability diagrams based on Fe–O–C and Fe–O–H systems are employed to enhance the understanding of reduction behavior. Results revealed that an increased gas flow rate significantly accelerated the reduction rate due to enhanced gas diffusion, while elevated pressure facilitated the reduction of wüstite to metallic iron. Notably, the DRI pellet achieves around 90% metallization degree reduction with hydrogen, but the introduction of carbon monoxide into the reducing gas prevented the reduction of the DRI pellet. In the case of BF pellet reduction, approximately 20% metallization degree is observed using H2–CO (50:50), yet subsequent reoxidation of the reduced iron to wüstite and magnetite occurred. Further investigation identified a significant increase in the partial pressure of H2O and CO2, particularly within the surface porosities, as the underlying cause of this reoxidation phenomenon.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
APXPS, Direct reduced iron, Hydrogen reduction, Reoxidation, Surface reduction
in
International Journal of Hydrogen Energy
volume
83
pages
14 pages
publisher
Elsevier
external identifiers
  • scopus:85201403832
ISSN
0360-3199
DOI
10.1016/j.ijhydene.2024.08.094
language
English
LU publication?
yes
id
e680bedb-ded6-41cd-93f5-e63518716cd1
date added to LUP
2024-10-28 13:02:47
date last changed
2025-04-04 14:59:35
@article{e680bedb-ded6-41cd-93f5-e63518716cd1,
  abstract     = {{<p>Using Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS), this study investigates the reduction behavior of iron oxides in direct reduction (DRI) and blast furnace (BF) pellets. H<sub>2</sub>, CO, and a H<sub>2</sub>–CO mixture are used as reducing agents at 650 °C. The investigation aimed to elucidate variations in the rate of reduction over time and under different conditions. Additionally, contour plots are generated to visualize the X-ray photoelectron peak intensity variations as a function of time. Furthermore, phase stability diagrams based on Fe–O–C and Fe–O–H systems are employed to enhance the understanding of reduction behavior. Results revealed that an increased gas flow rate significantly accelerated the reduction rate due to enhanced gas diffusion, while elevated pressure facilitated the reduction of wüstite to metallic iron. Notably, the DRI pellet achieves around 90% metallization degree reduction with hydrogen, but the introduction of carbon monoxide into the reducing gas prevented the reduction of the DRI pellet. In the case of BF pellet reduction, approximately 20% metallization degree is observed using H<sub>2</sub>–CO (50:50), yet subsequent reoxidation of the reduced iron to wüstite and magnetite occurred. Further investigation identified a significant increase in the partial pressure of H<sub>2</sub>O and CO<sub>2</sub>, particularly within the surface porosities, as the underlying cause of this reoxidation phenomenon.</p>}},
  author       = {{Heidari, Aidin and Ghosalya, Manoj Kumar and Alaoui Mansouri, Mohammed and Heikkilä, Anne and Iljana, Mikko and Kokkonen, Esko and Huttula, Marko and Fabritius, Timo and Urpelainen, Samuli}},
  issn         = {{0360-3199}},
  keywords     = {{APXPS; Direct reduced iron; Hydrogen reduction; Reoxidation; Surface reduction}},
  language     = {{eng}},
  pages        = {{148--161}},
  publisher    = {{Elsevier}},
  series       = {{International Journal of Hydrogen Energy}},
  title        = {{Hydrogen reduction of iron ore pellets : A surface study using ambient pressure X-ray photoelectron spectroscopy}},
  url          = {{http://dx.doi.org/10.1016/j.ijhydene.2024.08.094}},
  doi          = {{10.1016/j.ijhydene.2024.08.094}},
  volume       = {{83}},
  year         = {{2024}},
}