METHOD OF PRODUCING ELEMENTARY SULPHUR FROM SULPHUR DIOXIDE-CONTAINING EXHAUST GAS Russian patent published in 2013 - IPC C01B17/04 

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry and can be used to produce elementary sulphur from exhaust gas which contains sulphur dioxide at chemical, petrochemical, gas processing and metallurgical companies. The method involves concentrating sulphur dioxide extracted from exhaust gas; partial high-temperature reduction of the concentrated sulphur dioxide with a gaseous reducing agent to sulphur, hydrogen sulphide and water; condensation of the formed sulphur vapour with removal of liquid sulphur into a sulphur collecting tank; processing the exhaust process gas by successive catalytic Claus conversion and subsequent cleaning of the process gas from the last catalytic stage, which contains residual amounts of H₂S, SO₂, H₂ and water vapour. To this end, the process gas is fed into the reactor of a cleaning unit in which H₂S reacts with SO₂ in aqueous solution to form a suspension of sulphur in water and in which temperature gradient of 20-60°C is maintained in the cold part and 70-100°C in the hot part, and counter flow of the gaseous and liquid phases is formed. Gas which consists of unreacted hydrogen, traces of hydrogen sulphide and sulphur dioxide is separated from the suspension and returned to the high-temperature reduction step.

EFFECT: high efficiency of the method.

4 cl, 1 dwg, 1 ex