The catalytic reduction of SO2 to elemental sulfur by CO or CH4 over ceria-based catalysts under demanding operating conditions is reported in this paper. Cuor Ni-containing ceria catalysts have been shown before to be highly active and selective for SO2 reduction by CO in dry gas streams or in the presence of low amounts of H2O. In this work, the activity/selectivity of 10 at.%La-doped ceria, ...

The catalytic reduction of SO2 to elemental sulfur by methane was studied over ceria-based catalysts. Both La-doped and undoped ceria were found to catalyze the SO2 reduction by CH4 in the temperature range of 550–750◦C at atmospheric pressure and with feed gases containing a molar ratio of CH4/SO2 = 0.5–3. At temperatures below ∼550◦C, the catalyst surface is capped by SO2. The reaction light-...

The catalytic reduction of sulfur dioxide with methane to form elemental sulfur has been studied. Al2O3, Cu-Al2O3 and Ni-Al2O3 were examined as catalysts and their performances were compared in terms of SO2 conversion and selectivity. Performance of the catalyst extremely enhanced when nickel and copper were added as promoters. The effects of temperature, SO2/CH4 molar ratio, and reaction...

Complete treatment of sulfur dioxide (SO2) from flue gases in a two-stage process consisting of a biotrickling filter followed by biological post-treatment unit was investigated. The biotrickling filter could remove 100% of influent SO2 from simulated flue gas at an empty bed residence time of 6 s for a concentration range of 300-1000 ppm(v). All the absorbed SO2 was recovered in the biotrickli...

The catalyst activity of fluorite-type oxide, such as ceria and zirconia, for the reduction of sulfur dioxide by carbon monoxide to elemental sulfur can be significantly promoted by active transition metals, such as copper. More than 95% elemental sulfur yield, corresponding to almost complete sulfur dioxide conversion, was obtained over a Cu-Ce-O oxide catalyst with a feed gas of stoichiometri...

Mass-independent fractionation of sulfur isotopes (S MIF) in Archean and Paleoproterozoic rocks provides strong evidence for an anoxic atmosphere before ~2,400 Ma. However, the origin of this isotopic anomaly remains unclear, as does the identity of the molecules that carried it from the atmosphere to Earth's surface. Irrespective of the origin of S MIF, processes in the biogeochemical sulfur c...

This report presents the chemical and physical factors governing the generation of sulfur dioxide (SO2), its transformation into other sulfur compounds, and the removal of sulfur oxides within the cement kiln system. Sulfur in cement kilns is derived from both kiln feed and from the kiln fuel. The form of the sulfur dictates the location in the kiln where the SO2 generation takes place. Sulfur ...

Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H2S and SO2) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative ...

Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H2S and SO2) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative ...

An on-line method for S-isotope analysis is described. Samples are combusted in an elemental analyzer. SO2 is separated from other combustion gases by gas chromatography, and the gases enter the ion source of the mass spectrometer through a split interface. Integrated peak areas for %O2+ and %OZ+ are compared to the response for a standard gas sample to determine the 6% value. 6% values of samp...