METHOD OF OBTAINING ELEMENTAL SULPHUR FROM SULPHUR DIOXIDE-CONTAINING DISCHARGE GAS Russian patent published in 2014 - IPC C01B17/04 

FIELD: chemistry.

SUBSTANCE: method includes concentration of sulphur dioxide, partial high-temperature reduction of the concentrated sulphur dioxide with concentrated hydrogen to sulphur, hydrogen sulphide and water, condensation of the formed sulphur vapour with output of a liquid medium into a sulphur collector. Then, processing of discharged technological gas by catalytic Claus-conversion, and following purification of the tail gas, which contains residual quantities of H₂S, SO₂, N₂ and water vapours, is carried out. A part of flow of concentrated sulphur dioxide is diverted by a bypass line, skipping stages of high temperature reduction, condensation of sulphur and catalytic convention, and the discharged from a catalytic stage of Claus-conversion tail gas is introduced into a hydrogenation unit. Gas after hydrogenation, consisting of H₂S, H₂ and water vapours, is supplied into a condensation column for water separation. Dehydrated gas is mixed with a bypass flow of concentrated sulphur dioxide and a mixture is directed to an additional catalytic stage of Claus-conversion, residual gases after which are returned to the input of any catalytic stage, which precedes the hydrogenation unit.

EFFECT: increase of the outgoing gas utilisation efficiency.

8 cl, 2 dwg, 1 ex