Catalytic Conversion of Multipollutants (Hg⁰/NO/Dioxin) with V₂O₅-WO₃/TiO₂ Catalysts

A multipollutant (Hg⁰/NO/dioxin)-containing gas-stream-generating system is developed to investigate the effectiveness of V₂O₅-WO₃/TiO₂ catalyst for multipollutant control. The results indicate that plate-type 1.52 wt% V₂O₅ performs much better than two other catalysts for oxidizing Hg⁰. With a higher vanadium loading of 1.52 wt% V₂O₅, higher Hg⁰ conversions (53-75%) are observed compared to 0.66 wt% V₂O₅ (45-68%) and 0.26 wt% V₂O₅ (32-63%) for simulated flue gas streams. In addition, the mercury oxidation activity significantly increases with increasing concentration of hydrogen chloride. For removal of PCDD/Fs, the results show that the removal efficiencies of PCDD/F congeners achieved with V₂O₅-WO₃/TiO₂ range from 50% to 65%. It is observed that the removal efficiency of highly chlorinated PCDD/Fs is slightly higher than that of low-chlorinated PCDD/Fs. Overall, plate-type catalyst of 1.52 wt% V₂O₅ shows the highest Hg⁰/NO/dioxin conversion and reduction efficiency among three catalysts evaluated.