Reverse-flow reactor concept for combined SO2 and co-oxidation in smelter off-gases

• CO may complicate abatement of SO2 in waste gases of non-ferrous smelters.
• Low-temperature oxidation of CO in the RFR may prevent reactor overheating.
• Pt fiber-glass catalyst is suitable for CO oxidation in presence of SO2.
• The novel RFR concept for SO2 oxidation in presence of CO is proposed.

The study is dedicated to the problem of CO admixtures in the SO2-containing waste gases of non-ferrous smelters which may significantly complicate the operation of SO2 oxidation reverse-flow reactors, used for purification of such gases, due to catalyst overheating, decrease of SO2 conversion and worsening of operation stability. The concept of the reverse-flow reactor with additional catalyst beds for separate CO oxidation between the beds of vanadia catalyst and inert heat regenerative material was proposed. The catalyst with Pt supported in small amount (0.01–0.1% mass) at SiO2–ZrO2 glass fabric (Pt–GFC) was experimentally found to have the sufficient activity in CO oxidation at moderate temperatures combined with experimentally proven high resistance to deactivation by SOx. According to mathematical simulation data, the proposed approach provides efficient elimination of the reverse-flow reactor overheating and subsequent problems, caused by CO appearance in smelter waste gases.

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