Process for the thermal reduction of sulfur dioxide to sulfur

A thermal reduction process for the production of sulfur from sulfur dioxide (SO2)-containing effluent streams, the process comprising:

• combining a sulfur dioxide-containing effluent stream with an oxygen-containing gas stream comprising oxygen in a first preheater to elevate the temperature of the gaseous mixture to a temperature ranging from about 500° C. to about 650° C.;
• heating a hydrocarbon gas stream in a second preheater to a temperature ranging from about 500° C. to about 650° C.;
• concurrently contacting an oxygen-containing gas stream with the sulfur dioxide-containing effluent gas stream and the hydrocarbon gas stream in a single, primary reaction furnace for a period of time sufficient to produce a reducing gas effluent stream comprising hydrogen sulfide (H2S) and hydrogen gas;
• contacting the reducing gas effluent stream from the reaction furnace with an activated catalyst in a first reaction zone comprising a catalyst system at a temperature effective for the reaction between hydrogen sulfide and sulfur dioxide to generate a product gas stream comprising elemental sulfur and water by way of the Claus reaction;
• further contacting the effluent gas stream from the first reaction zone with one or more additional catalytic reaction zones comprising one or more additional catalysts;
• and
• recovering the elemental sulfur from the product gas stream.