General process begins with compressed air, compressed from the turbine driven centrifugal compressor and mixed with superheated ammonia vapor.
This mixture flows through the ammonia converter where the ammonia is catalytically oxidized to nitric oxide. The process gas leaves the catalyst gauze and passes in succession through the turbine gas heater, the burner gas boiler, the platinum recovery filter, the tail gas heater, the boiler feed water heater, the nitric gas cooler and the water cooled weak acid condenser.
The gas at about 140 degrees F enters the absorption tower below the oxidation trays. The acid condensed which is approximately 80wt.% HNO3 flows to the corresponding trays in the absorption tower.
In the absorption town Nitrogen dioxide forms nitric acid by reaction with the water on the bubble cap trays in the tower. Tail gas is processed and vented to the atmosphere.