Oxygen or oxygen-enriched air is employed to support combustion in furnace
(16) of part of the hydrogen sulphide content of a first feed gas stream.
Sulphur is extracted from the resulting gas stream in a sulphur condenser (26).
Catalyst Claus reaction between hydrogen sulphide and sulphur dioxide in the resulting
sulphur vapour depleted gas stream takes place in a catalytic reactor (32).
Sulphur is extracted in a further sulphur condenser (34). The resulting
sulphur vapour depleted gas stream is passed into a catalytic reduction reactor
(40) in which all the residual sulphur dioxide and any sulphur vapour are
reduced to hydrogen sulphide. The resulting reduced gas mixture has water vapour
extracted there from in a quench tower (52). The resulting water vapour
depleted gas stream flows to a Claus plant for further treatment typically together
with a second feed gas stream.
