| abstract |
Sour water is stripped with air in a tower to remove hydrogen sulfide, and the evolved gas is scrubbed with an aqueous chelated iron solution in an upper portion of the tower to absorb the hydrogen sulfide and oxidize it to sulfur. The treated gas is discharged from the top of the tower. In the lower portion of the tower the chelated iron solution mixes with the sour water and effects removal of residual hydrogen sulfide in solution in the water. The stripping air is introduced into the lower portion of the tower and also functions to reoxidize the chelated iron solution to maintain its activity. The treated water containing chelated iron and sulfur solids is withdrawn from the bottom of the tower and a major portion is preferably recycled and fed to the stripping zone along with the inlet sour water. After separation and recovery of the sulfur solids, if desired, the remainder of the stream is discharged to waste. |