To remove dissolved hydrogen sulfide (H2S) and H2Sx from liquid sulfur coming from Claus units. Liquid sulfur from Claus units contains approximately 300 ppmw dissolved H2S and H2Sx; to meet environmental and safety restrictions the liquid sulfur should be degassed such that less than 10ppmw H2S remains.
Description: Sulfur from the Claus unit is rundown into either a concrete sulfur pit or a steel vessel. It is then circulated over a stripping (bubble) column by bubbling air through the sulfur. By agitating the sulfur in this way, H2S is released. Sweep air is passed over the top of the sulfur to remove released H2S. The vent gasses are usually sent to an incinerator via an ejector. The degassed sulfur is then pumped into storage. The advantage to this process is that there are no moving parts and no catalyst is required, consequently, the process is easy to operate.
Economics: The Shell sulfur degassing process has been developed to decrease residence time and consequently capital expenditure. Operational costs are kept low as no catalyst is required.
Licensor: Shell Global Solutions International B.V. and Jacobs Nederland B.V.