The retardation kinetics of magnetite reduction using H2 and H2-H2O mixtures

Wan Ho Kim, Seungmoon Lee, Sung Man Kim, Dong Joon Min

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Cylindrical compacts of magnetite were isothermally reduced at 773-1273 K with pure H2 or H2-H2O mixtures. The initial reduction rates increased with temperature and partial pressures of H 2 in the H2-H2O mixtures. However, with progressing reduction, a dense iron layer formed around the wüstite grains and the rate significantly reduced. In this regime, solid state oxygen diffusion through the dense iron layer was rate limiting. This retardation of reduction occurred at degrees of reduction of 51-89%, depending on the temperature and H2 partial pressure, which has a linear relationship with the dimensionless kinetic parameter, k1 mixed/k 2 mixed, (k1 mixed, k2 mixed: contribution of gaseous mass transport (GMT) and interfacial chemical reaction (ICR) to the reduction rate, respectively) in the reaction-regime controlled by a combination of both mechanisms. However, under certain conditions (H2, H2-10%H2O, 773 K//H2-10, 20%H2O, 873 K//H2-20%H2O, 973 K) the retardation was absent because of the formation of a microporous iron layer product.

Original languageEnglish
Pages (from-to)4194-4200
Number of pages7
JournalInternational Journal of Hydrogen Energy
Volume38
Issue number10
DOIs
Publication statusPublished - 2013 Apr 1

Fingerprint

Magnetite
magnetite
Kinetics
kinetics
Iron
iron
Partial pressure
partial pressure
Kinetic parameters
Chemical reactions
chemical reactions
Mass transfer
solid state
Temperature
Oxygen
temperature
oxygen
products

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

Cite this

Kim, Wan Ho ; Lee, Seungmoon ; Kim, Sung Man ; Min, Dong Joon. / The retardation kinetics of magnetite reduction using H2 and H2-H2O mixtures. In: International Journal of Hydrogen Energy. 2013 ; Vol. 38, No. 10. pp. 4194-4200.
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The retardation kinetics of magnetite reduction using H2 and H2-H2O mixtures. / Kim, Wan Ho; Lee, Seungmoon; Kim, Sung Man; Min, Dong Joon.

In: International Journal of Hydrogen Energy, Vol. 38, No. 10, 01.04.2013, p. 4194-4200.

Research output: Contribution to journalArticle

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