View in EDS

Kinetics and microstructural evolution of iron oxide pellets reduced by H2/CO mixtures: Implications for hydrogen-based direct reduction.

Saved in:
Bibliographic Details
Title: Kinetics and microstructural evolution of iron oxide pellets reduced by H2/CO mixtures: Implications for hydrogen-based direct reduction.
Authors: Cheng, Qiang1 (AUTHOR), Guo, Hongwei1 (AUTHOR), Yan, Bingji1 (AUTHOR) bjyan@suda.edu.cn
Source: International Journal of Hydrogen Energy. Jan2026, Vol. 205, pN.PAG-N.PAG. 1p.
Subjects: Chemical reduction kinetics, Iron oxides, Mass transfer coefficients, Morphology, Iron, Gas mixtures, Industrial applications, Diffusion control
Abstract: This study systematically examines the reduction kinetics and associated microstructural evolution of high-purity iron oxide (Fe 2 O 3) pellets during gas-based reduction in H 2 /CO mixtures at temperatures ranging from 850 to 1000 °C. The reduction mechanism is determined to conform to the unreacted core model, exhibiting a distinct kinetic transition: the initial stage is governed by the Spherical Shrinking Model, while the later stage shifts to diffusion control, following the Ginstling-Brounshtein Diffusion Model. Microstructural characterization via Scanning Electron Microscopy and Industrial Computed Tomography reveals that the reducing agent profoundly influences the morphology of the metallic iron product. H 2 reduction generates a highly porous, sponge-like iron structure with extensive pore connectivity, facilitating gas permeability. In contrast, CO reduction results in denser, layered iron formations with irregular pores, phenomena exacerbated by carbon deposition and swelling. Quantitative analysis corroborates that H 2 -reduced pellets possess superior pore sphericity (14.6 % > 0.8 sphericity) and connected porosity (24.26 %), thereby optimizing reduction efficiency. Conversely, CO-reduced pellets exhibit inferior sphericity (3.2 % > 0.8 sphericity) and a higher proportion of isolated pores (16.32 % connectivity), which impedes deep reduction. These findings provide critical insights for optimizing Direct Reduction Iron (DRI) processes, underscoring the significant advantages of employing H 2 in industrial applications. • H 2 creates superior porous microstructure with high connectivity. • The properties of pores provide insights into kinetic mechanisms. • Findings strongly support the H 2 -rich DRI production. [ABSTRACT FROM AUTHOR]
Copyright of International Journal of Hydrogen Energy is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
FullText Text:
  Availability: 0
Header DbId: egs
DbLabel: Engineering Source
An: 190962002
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Kinetics and microstructural evolution of iron oxide pellets reduced by H2/CO mixtures: Implications for hydrogen-based direct reduction.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Cheng%2C+Qiang%22">Cheng, Qiang</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Guo%2C+Hongwei%22">Guo, Hongwei</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Yan%2C+Bingji%22">Yan, Bingji</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> bjyan@suda.edu.cn</i>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22International+Journal+of+Hydrogen+Energy%22">International Journal of Hydrogen Energy</searchLink>. Jan2026, Vol. 205, pN.PAG-N.PAG. 1p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Chemical+reduction+kinetics%22">Chemical reduction kinetics</searchLink><br /><searchLink fieldCode="DE" term="%22Iron+oxides%22">Iron oxides</searchLink><br /><searchLink fieldCode="DE" term="%22Mass+transfer+coefficients%22">Mass transfer coefficients</searchLink><br /><searchLink fieldCode="DE" term="%22Morphology%22">Morphology</searchLink><br /><searchLink fieldCode="DE" term="%22Iron%22">Iron</searchLink><br /><searchLink fieldCode="DE" term="%22Gas+mixtures%22">Gas mixtures</searchLink><br /><searchLink fieldCode="DE" term="%22Industrial+applications%22">Industrial applications</searchLink><br /><searchLink fieldCode="DE" term="%22Diffusion+control%22">Diffusion control</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: This study systematically examines the reduction kinetics and associated microstructural evolution of high-purity iron oxide (Fe 2 O 3) pellets during gas-based reduction in H 2 /CO mixtures at temperatures ranging from 850 to 1000 °C. The reduction mechanism is determined to conform to the unreacted core model, exhibiting a distinct kinetic transition: the initial stage is governed by the Spherical Shrinking Model, while the later stage shifts to diffusion control, following the Ginstling-Brounshtein Diffusion Model. Microstructural characterization via Scanning Electron Microscopy and Industrial Computed Tomography reveals that the reducing agent profoundly influences the morphology of the metallic iron product. H 2 reduction generates a highly porous, sponge-like iron structure with extensive pore connectivity, facilitating gas permeability. In contrast, CO reduction results in denser, layered iron formations with irregular pores, phenomena exacerbated by carbon deposition and swelling. Quantitative analysis corroborates that H 2 -reduced pellets possess superior pore sphericity (14.6 % > 0.8 sphericity) and connected porosity (24.26 %), thereby optimizing reduction efficiency. Conversely, CO-reduced pellets exhibit inferior sphericity (3.2 % > 0.8 sphericity) and a higher proportion of isolated pores (16.32 % connectivity), which impedes deep reduction. These findings provide critical insights for optimizing Direct Reduction Iron (DRI) processes, underscoring the significant advantages of employing H 2 in industrial applications. • H 2 creates superior porous microstructure with high connectivity. • The properties of pores provide insights into kinetic mechanisms. • Findings strongly support the H 2 -rich DRI production. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of International Journal of Hydrogen Energy is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=190962002
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1016/j.ijhydene.2025.153100
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 1
        StartPage: N.PAG
    Subjects:
      – SubjectFull: Chemical reduction kinetics
        Type: general
      – SubjectFull: Iron oxides
        Type: general
      – SubjectFull: Mass transfer coefficients
        Type: general
      – SubjectFull: Morphology
        Type: general
      – SubjectFull: Iron
        Type: general
      – SubjectFull: Gas mixtures
        Type: general
      – SubjectFull: Industrial applications
        Type: general
      – SubjectFull: Diffusion control
        Type: general
    Titles:
      – TitleFull: Kinetics and microstructural evolution of iron oxide pellets reduced by H2/CO mixtures: Implications for hydrogen-based direct reduction.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Cheng, Qiang
      – PersonEntity:
          Name:
            NameFull: Guo, Hongwei
      – PersonEntity:
          Name:
            NameFull: Yan, Bingji
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 30
              M: 01
              Text: Jan2026
              Type: published
              Y: 2026
          Identifiers:
            – Type: issn-print
              Value: 03603199
          Numbering:
            – Type: volume
              Value: 205
          Titles:
            – TitleFull: International Journal of Hydrogen Energy
              Type: main
ResultId 1