The present application relates to a process for treating the off gas from a carbon black process, said process comprising the steps of: providing an off gas from a carbon black process, reacting said off gas in a first reaction step forming water and S, and condensing the S at a temperature Tcon where S is in a liquid phase and the water is in gas form thereby achieving a gaseous stream comprising water and a liquid stream comprising S, and wherein the first reaction step is carried out over a monolith catalyst.

A method for cleaning an off-gas from viscose production, essentially containing H.sub.2S and CS.sub.2, comprises passing the gas through a catalytic reactor containing a direct oxidation type catalyst, such as V.sub.2O.sub.3 on silica, to convert H.sub.2S in the gas to elemental sulfur, SO.sub.2 or mixtures thereof, either via the oxygen present in the gas or via oxygen added to the gas stream. Elemental sulfur and SO.sub.2 are removed from the effluent gas from the catalytic reactor, and the unconverted CS.sub.2 is recycled to the viscose production process.

Described is a process for treatment of a fluid comprising an oxidizable contaminant selected from one or both of a sulfide and a thiol, the process comprising the step of contacting the fluid with a first complex of ferric iron and a polyphosphate to oxidize the oxidizable contaminant and generate a second complex of ferrous ion and the polyphosphate.

Presented is a catalyst composition having exceptional properties for converting sulfur, sulfur compounds, and carbon monoxide contained in gas streams by catalyzed hydrolysis, hydrogenation and water-gas shift reactions. The catalyst comprises underbedded molybdenum and cobalt with an overlayer of molybdenum and cobalt. These metals are present in the catalyst within certain concentration ranges and relative weight ratios. The underbedded metals are present in the catalyst within a specified range relative to the overlayer and total metals. The underbedded metals are formed by co-mulling an inorganic oxide with the catalytically active metals of molybdenum and cobalt. The co-mulled mixture is calcined and then impregnated with overlaid molybdenum and cobalt.

A sulfur recovery unit (SRU) and method including converting hydrogen sulfide to elemental sulfur via the SRU having a reaction furnace and three catalytic reactors including a first catalytic reactor, a second catalytic reactor, and a third catalytic reactor disposed operationally in series, wherein catalyst in the first catalytic reactor consists of alumina catalyst, and wherein catalyst in the second catalytic reactor consists of a first layer of alumina catalyst, a second layer of hydrogenation catalyst, and a third layer of titania catalyst.

Metamaterials may be utilized to facilitate conversion of hydrogen sulfide into elemental hydrogen and elemental sulfur in the presence of suitable photocatalyst particles. Photoreactor systems utilizing metamaterials may comprise a flow-through reaction space having at least one metamaterial-catalyst surface. The at least one metamaterial-catalyst surface comprises a metamaterial surface having a plurality of resonators patterned thereon and a plurality of photocatalyst particles located upon at least a portion of the resonators, within a gap between a first region and a second region of one or more resonators, or within a gap between adjacent resonators. The plurality of photocatalyst particles comprise at least one photocatalyst effective to convert hydrogen sulfide into elemental hydrogen and elemental sulfur upon exposure to electromagnetic radiation.

A multi-metal composition and a method utilizing the multi-metal composition is disclosed. The multi-metal composition may comprise: an alloy comprising at least five elements selected from the group consisting of Co, Cr, Fe, Mn, Ni, Al, Mg, Cu, Zn, Zr, Ru, Rh, Pd, Ag, W, Re, Ir, Pt, Pd, Au, Ce, Yb, Sn, Ca, Be, Mo, V, W, and Sr. The method may comprise: providing a multi-metal composition comprising an alloy comprising at least five elements selected from the group consisting of Co, Cr, Fe, Mn, Ni, Al, Mg, Cu, Zn, Zr, Ru, Rh, Pd, Ag, W, Re, Ir, Pt, Pd, Au, Ce, Yb, Sn, Ca, Be, Mo, V, W, and Sr; and interacting a gas stream comprising hydrogen sulfide with the multi-metal composition.