The SUPERCLAUS process recovers elemental sulfur from hydrogen sulfide (H2S) containing gases originating from gas treating plants such as alkanolamine units or physical solvent plants. Modern SUPERCLAUS plants should be able to process H2S/ammonia (NH3) containing gases as well, originating from sour water strippers, to yield up to 99.4% overall sulfur recovery without any further tail gas clean-up.
The SUPERCLAUS process has a thermal stage followed by three catalytic reaction stages with sulfur removed between stages by condensers. Two reactors are filled with standard Claus catalyst while the last reactor is filled with a new selective oxidation catalyst.
In the thermal stage, the acid gas is burned with a substoichiometric amount of controlled combustion air such that the tail gas leaving the second reactor contains typically 0.8 vol.% to 1.0 vol.% of H2S. The catalyst in the third reactor oxidizes H2S to sulfur at more than 85% efficiency.
However, because the new catalyst neither oxidizes H2S to SO2 and water nor reverses the reaction; total sulfur recovery up to 99% can be obtained. If sulfur recovery more than 99% is required, one additional Claus reactor stage will be installed upstream of the selective oxidation reactor.
Licensor: Comprimo Sulfur Solutions, a member of Jacobs Engineering Group