Sulfur Dioxide Promoted Mercury Fast Deposition over a Selenite-Chloride-Induced Surface from Wet Flue Gas

A novel surface-induced method usingselenite-chloride intermediato reverse the effect of flue gas SO2 and H2O realized Hg-0 fast deposition and stabilization. Gaseous elemental mercury (Hg-0) extractionfrom industrialflue gases is undergoing intense research due to its unique properties.Selective adsorption that renders Hg-0 to HgO or HgS overmetal oxide- or sulfide-based sorbents is a promising method, yetthe sorbents are easily poisoned by sulfur dioxide (SO2) and H2O vapor. The Se-Cl intermediate derived from SeO2 and HCl driven by SO2 has been demonstrated tostabilize Hg-0. Thus, a surface-induced method was put forwardwhen using & gamma;-Al2O3 supported selenite-chloride(xSeO(3) (2-)-yCl(-), named xSe-yCl) for mercury deposition. Results confirmed that under 3000 ppmSO(2) and 4% H2O, Se-2Cl exhibited the highestinduced adsorption performance at 160 & DEG;C and higher humiditycan accelerate the induction process. Driven by SO2 underthe wet interface, the in situ generated active Se-0 hashigh affinity toward Hg-0, and the introduction of Cl- enabled the fast-trapping and stabilization of Hg-0 due to its intercalation in the HgSe product. Additionally,the long-time scale-up experiment showed a gradient color change ofthe Se-2Cl-induced surface, which maintained almost 100% Hg-0 removal efficiency over 180 h with a normalized adsorption capacityof 157.26 mg/g. This surface-induced method has the potential forpractical application and offers a guideline for reversing the negativeeffect of SO2 on gaseous pollutant removal.

Automated summary

A novel surface-induced method using selenite-chloride intermediato was developed for fast deposition and stabilization of elemental mercury (Hg-0) from flue gas. The method utilizes Se-Cl intermediate to stabilize Hg-0 and shows high adsorption performance under specific conditions. The long-term experiment also demonstrates the potential for practical application with almost 100% Hg-0 removal efficiency over 180 hours.