Process compatible desulfurization of new suspension preheater cement production: Rapid catalytic oxidation of trace SO2 over V2O5-based catalysts in preheater environment

Efficient capture of sulfur dioxide (SO₂) in the preheater of the cement production system is the key to achieving process compatible flue gas desulfurization (FGD). Herein, the rapid oxidation of trace SO₂ over V₂O₅-based catalysts in the preheater environment was realized to enhance the SO₂ capture capacity of limestone in raw meal, and the catalytic efficiency was further improved by 45.2%, 56.1% and 61.9% after introducing TiO₂/MnO₂/CeO₂ as cocatalysts, respectively. The V₂O₅-based catalysts had superior catalytic behavior only when the flue gas temperature exceeded 500 °C, while the composition variation of flue gas had a minor influence on SO₂ oxidation. Finally, a maximum SO₂ oxidation efficiency of 68.1% was achieved in the presence of 4.0% O₂, 25.0% CO₂ and 15.0% H₂O at 600 °C. Furthermore, the mechanism of SO₂ catalytic oxidation over V₂O₅-based catalysts was deduced based on the results of XRD, BET, XPS and Raman, and V⁵⁺ was identified as the primary vanadium species for SO₂ oxidation. The results provide a deeper insight into the catalytic oxidation of SO₂ in the preheater environment, and then facilitate the improvement of process compatible FGD and available dry FGD technologies for cement industry.