Units
H2S Scavengers – Treating and Removal
For very low-capacity H2S bearing streams, process vent streams, and direct gas treating including biogas processes, anaerobic digestion, and landfill gas that cannot be efficiently or cost-effectively treated through traditional amine and sulfur recovery units, H2S scavengers can be an excellent option. While most scavenger technologies require increased operating costs for reagent replacement and disposal, Iron Sponge, fixed bed treating, and absorbent systems offer low CapEx investment.
H2S scavenging means removing small amounts of H2S from a larger stream and is used in the direct treatment of gaseous process streams or vents. Scavengers are typically solid absorbents ranging from iron sponge, which has been used since 1875, to modern high-capacity absorbent solid media. Scavengers are rarely regenerated and create a solid waste stream typically disposed of in a landfill.
Scavenging systems usually contain just two vessels and don’t require additional process equipment like pumps or heat exchangers. The vessels contain a layer of scavenging media on a support system and a gas distributor. They are operated in a lead-lag configuration where the first vessel processes incoming gasses while the lag vessel is on standby loaded with fresh media. When media in the lead vessel is spent, the operation is switched to the standby vessel, the first vessel’s spent charge is dumped, and it is reloaded with new media.
Scavengers are cost-effective in applications with sulfur removal requirements <0.25 to 0.5 long tons per day. To perform correctly and maintain process onstream time, designers must select the right scavenging technology for the application and adequately size treating vessels. Stream H2S monitors and switching valves can be added for alarming and process automation. An improperly sized scavenging system can lead to operational headaches and unnecessary process outages.
PTI’s engineers and designers have the know-how and experience to help you with your small-scale scavenging application.
Contact us to discuss your Hydrogen Sulfide treatment challenges.
