Direct Reduction of SO₂ to Elemental Sulfur by the Coupling of Cold Plasma and Catalyst (I)

Abstract

The direct reduction of SO2 to elemental sulfur in flue gas by the coupling of cold plasma and catalyst, being a new approach for SO2 reduction, was studied. In this process, CO2 can be disassembled to form CO, which acts as the reductant under the cold plasma. With the coupling of the cold plasma and the catalyst, sulfur dioxide was selectively reduced by CO to elemental sulfur with a byproduct of metal sulfate, e.g., FeSO4. In the present work, Fe2O3/γ-Al2O3 was employed as the catalyst. The extent of desulfurization was more than 80%, and the selectivity of elemental sulfur is about 55%. The effects of water vapor, temperature, and the components of simulated flue gas were investigated. At the same time, the coupling of thermogravimetry and infrared method and a chemical analysis method were employed to evaluate the used catalyst. In this paper, we will focus on the discussion of the catalyst. The discussions of the detail of plasma will be introduced in another paper.

Catalytic Reaction Assisted by Plasma or Electric Field

“…Application of non‐equilibrium plasma for biomethane conversion enables the direct conversion of biomethane to syngas by dry reforming. Also, H 2 S was desulfurized to solid sulfur simultaneously by virtue of the plasma reactivity . Dry reforming of biomethane can occur as described in eq.…”

Simultaneous dry reforming and desulfurization of biomethane with non-equilibrium electric discharge at ambient temperature

“…So far there were some reports for effective utilization of electrical discharge (Ban et al, 2004;Chavadej et al, 2005;Kim et al, 2002;Larkin et al, 2001;Li et al, 2002Li et al, , 2004Liu et al, 1999;Shao et al, 2004;Zou et al, 2003) and an electrical discharge could convert methane and carbon dioxide mixture into hydrogen and carbon monoxide at ambient temperature without any catalyst by dry reforming of methane (Eq. (1)).…”

One-Step Low-Temperature Reduction of Sulfur Dioxide to Elemental Sulfur by Plasma-Enhanced Catalysis

“…Considerable efforts have been dedicated to the use of NTP in air pollution control applications, like volatile organic compounds (VOC) and NO x removal, CO 2 activation, − as well as CH 4 conversion. , While some work has been devoted to SO 2 removal from flue gas via oxidation by OH radicals to form H 2 SO 4 , only a few attempts were made to reduce SO 2 to elemental sulfur by plasma catalysis. , These attempts studied CO as the reductant, but no reports were found on using H 2 or CH 4 . SO 2 conversion to solid sulfur over sulfuric acid is highly desired as it is easier to handle and transport with no corrosion issues.…”

“…18,19 While some work has been devoted to SO 2 removal from flue gas via oxidation by OH radicals to form H 2 SO 4 , 20 only a few attempts were made to reduce SO 2 to elemental sulfur by plasma catalysis. 21,22 These attempts studied CO as the reductant, but no reports were found on using H 2 or CH 4 . SO 2 conversion to solid sulfur over sulfuric acid is highly desired as it is easier to handle and transport with no corrosion issues.…”