How does LO-CAT work?
The H2S containing gas comes in contact with LO-CAT solution in the “absorber.” The H2S is converted to elemental sulfur and is removed from the absorber with the “spent” catalyst solution. “Sweet gas” exits the absorber. The “spent” catalyst goes to the “oxidizer” where 1) air is blown into the catalyst solution to regenerate the iron catalyst; and 2) the elemental sulfur settles in a cone to create concentrated sulfur slurry. The sulfur slurry is pumped to the sulfur filter where sulfur is washed. Most catalyst is recycled back to the LO-CAT unit, while some catalyst and wash water exit LO-CAT as part of the sulfur product. In this process, iron, in its ferric state (+3), is held in solution by chelating agents. The intent of the process is to oxidize hydrosulfide (HS-) ions to elemental sulfur by the reduction of the ferric (Fe+3) iron to ferrous (Fe+2) iron, and the subsequent reoxidation of the ferrous ions to ferric ions by contact with air. The chemistry of all chelated iron pro
