Ammonia (NH3) and hydrogen sulfide (H2S) are usually encountered in refinery sour water stripper offgas. This gas is often processed in a Claus sulfur plant prior to venting to atmosphere. Ammonia must be completely destroyed in the Claus plant reaction furnace to prevent deposition of ammonia salts in the downstream equipment.
The process utilizes a split-flow reaction furnace to destroy NH3. All the NH3 containing sour water acid gases from the sour water stripper (SWS), and all the combustion air is mixed with a controlled portion of the amine acid gas stream from the amine treating units.
The furnace is divided into two zones. The NH3-rich stream combustion occurs in the first zone at 2,650°F to 2,800°F. This temperature is sufficiently high to ensure complete NH3 destruction. Zone 1 temperature is controlled by the amine acid gas amount diverted to that zone. The balance is sent to the reaction furnace’s Zone 2 and mixed with the combustion products from Zone 1.
Licensor: Fluor Enterprises, Inc.