Inhibiting the Carbon Deposition from the Reverse Boudouard Reaction in Refractories Submitted to CO–H2 Atmosphere

S. Brassamin, J. Kadok, C. Genevois, N. Bost, A. Coulon, M.R. Ammar , J. Poirier

CNRS, CEMHTI UPR 3079, University of Orléans, Orléans/France

Revision

Volume 11, Issue 2, Pages 83 - 91

Abstract

The catalytic decomposition of carbon monoxide via the reverse Boudouard reaction in the presence of a mixture of CO–H2 gas produces a solid sp2 carbon deposit, which has deleterious effects on refractory materials. The catalytic effects of iron oxides and the structural evolution of carbon during the reverse Boudouard reaction in CO–H2 atmosphere is investigated at a nano and micro-scale. Sulphur compounds inhibit the carbon monoxide dissociation on contact with iron and iron oxides. The samples were characterised by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy. A mechanism that governs the inhibition of the reaction is proposed and validated at lab scale, in which the formation of a very thin protective FeS layer (0,5–1 nm) is involved. This research is applied to develop ew CO/H2 resistant refractories.

Keywords

Boudouard reaction, carbon deposition, refractory damage, cementite, sulphur

References

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