Title

EFFECT OF WATER-GAS SHIFT REACTION ON REDUCTION OF IRON OXIDE POWDER PACKED BED WITH H₂-CO MIXTURES

EFFECT OF WATER-GAS SHIFT REACTION ON REDUCTION OF IRON OXIDE POWDER PACKED BED WITH H₂-CO MIXTURES

Authorship

USUI, TATEO; ONONAKAZATO, HIDEKI; YONEZAWA, TOSHINARI

USUI, TATEO

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ONONAKAZATO, HIDEKI

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YONEZAWA, TOSHINARI

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DOI

10.5151/2594-357x-34Red-561-570

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Abstract

Although the hydrogen reduction is thermally more disadvantageous than the CO reduction, it is advantageous that the reduction rate with H₂ is much larger than that with CO. In order to examine the effective use of hydrogen, the reduction of FeO₁.₀₅ powder packed bed with H₂-CO mixture was conducted, and the results were analyzed by a proposed model. In the proposed model, when the water-gas shift reaction is taken into account, the additivity is established on the dependence of the rate constant of the reaction on the gas composition. When the water-gas shift reaction is not taken into account, the rate constant deviates negatively from the additivity. The apparent rate constants of the reduction determined in the present study take the middle values, and the contribution of the water-gas shift reaction is estimated to be 3% against its equilibrium. In reducing FeO₁.₀₅ with CO, the time when the sample is perfectly reduced is shortened by adding a small amount of H₂, and the enhancement effect of H₂ on the gaseous reduction remarkably appears at 1093K. The effect originates in the proceeding of the water-gas shift reaction.

Although the hydrogen reduction is thermally more disadvantageous than the CO reduction, it is advantageous that the reduction rate with H₂ is much larger than that with CO. In order to examine the effective use of hydrogen, the reduction of FeO₁.₀₅ powder packed bed with H₂-CO mixture was conducted, and the results were analyzed by a proposed model. In the proposed model, when the water-gas shift reaction is taken into account, the additivity is established on the dependence of the rate constant of the reaction on the gas composition. When the water-gas shift reaction is not taken into account, the rate constant deviates negatively from the additivity. The apparent rate constants of the reduction determined in the present study take the middle values, and the contribution of the water-gas shift reaction is estimated to be 3% against its equilibrium. In reducing FeO₁.₀₅ with CO, the time when the sample is perfectly reduced is shortened by adding a small amount of H₂, and the enhancement effect of H₂ on the gaseous reduction remarkably appears at 1093K. The effect originates in the proceeding of the water-gas shift reaction.

Keywords

gaseous reduction, water-gas shift reaction, equilibrium constant, hydrogen reduction, iron oxide

gaseous reduction, water-gas shift reaction, equilibrium constant, hydrogen reduction, iron oxide