The 236 Series Gas Purifier utilizes a bed of iron sponge as the active media for H2S removal. In the Gas purification process, hydrogen sulfide is removed by passing sour gas through the purifier.
As the biogas goes through the purifier and reacts with the media, H2S is removed by reacting with the (Fe2O3). The chemical reaction results in forming ferric sulfide (Fe2S3), water and heat.
After some time, the sponge material is fully reacted. Spent sponge can then be regenerated through a reaction with atmospheric oxygen which converts Fe2S2 back to Fe2O3 and produces elemental sulfur. The reaction is exothermic.
Caking of the bed with the elemental sulfur limits the sponge life. H2S levels and pressure drop should be continuously measured at the outlet of the purifier.
When maximum allowable concentrations of H2S and pressure drop are beyond recommended levels, the media needs to be regenerated or replaced.
The unit can come with a continuous regeneration system wherein a set amount of air is controlled and injected to pre-mix with the biogas to regenerate the media.