The sour water stripping process is used to treat waste water generated from atmospheric and vacuum distillation, the hydrogenation process and the coking process in the refinery. Treated water can be reused as makeup water in refining processes, recovered ammonia can be used as a absorbent for the ammonia desulfurization process, and the acid separated can be sent to the acid gas treatment unit to produce sulfur and ammonium sulfate fertilizer.
An amine solution is used to absorb hydrogen sulfide (H2S) containing gases generated from refining processes such as product refining, atmospheric and vacuum distillation, residual oil hydrogenation, high-pressure hydrocracking, dry gas LPG refining, and ethylene recovery from dry gas. The rich amine solution can be regenerated in the stripping unit, yielding acid gas and lean amine solution.
Sour Water Stripping
The sour water stripping process is used to extract H2S and NH3 with pressurized steam at high temperature, which can be the single-column pressurized stripping process with the ammonia extraction or the single-column low-pressure stripping process.
Amine Solution Regeneration
The amine solution regeneration process is shown in the following figure.
Amine solution regeneration process flow:
Sour water stripping:
Treated water: H2S ≤ 20 ppm; NH3 ≤ 80 ppm
Amine solution regeneration:
Lean amine solution: H2S ≤ 0.8g/L; CO2 ≤ 0.2g/L