Polyoxometalate/Ionic Liquid Desulfurization System for Hydrogen Sulfide Removal from High-Temperature Gas Stream

The temperature of industrial gas containing harmful H(2)S can reach hundreds of degrees. However, few processes can be used directly for H(2)S removal from industrial high-temperature gas. In this work, three polyoxometalates with different central atoms ((n-Bu(4)N)(3)VMo(12)O(40), (n-Bu(4)N)(3)PMo(12)O(40), and (n-Bu(4)N)(4)[α-SiMo(12)O(40)]) were synthesized and dissolved in four ionic liquids (Bmim]Cl, [Bmim]HCO(3), [Bmim]Mes, or [Bmim]OAc) for H(2)S removal from high-temperature (90–180 °C) gases. The result showed that (n-Bu(4)N)(3)VMo(12)O(40)/[Bmim]OAc exhibited the optimal desulfurization performance, maintaining more than 98.6% desulfurization efficiency within 10 h. The reacted desulfurization solution can be regenerated by blowing air. FT-IR and XPS results show that both the central atom V and the coordination atom Mo of the polyoxometalate are involved in the oxidation of H(2)S; after the regeneration by introducing air, V(+IV) and Mo(+IV) recovered to V(+V) and Mo(+VI), respectively. Our research shows that (n-Bu(4)N)(3)VMo(12)O(40)/[Bmim]OAc is an efficient, easy-to-regenerate, and suitable high-temperature gas desulfurization solution.