Removal of CO2 and H2S from natural gas, syngas, etc. Removal of CO2 from ammonia syngas, ethylene oxide recycle gas, etc.
Product: Purified gas to meet pipeline or LNG plant, ammonia plant or petrochemical plant specifications as appropriate.
Acid gases are scrubbed from the feed in an absorber column (1) using potassium carbonate solution with Benfield additives to improve performance and avoid corrosion. The rich scrubbing solution is regenerated by reducing its pressure and stripping with steam in the stripper tower (2). Waste heat is commonly used to provide the steam. In the LoHeat version, the hot, lean solution is flashed by sending the steam through ejectors to reduce the energy requirements. In the HiPure version, acid gases are reduced to very low levels by polishing using an integrated DEA absorption loop.
Operating conditions: Absorption pressure is 150 to 1,800 psi, as available. Feed temperature is about 150°F to 250°F. If the feed is available at a higher temperature, that heat will be used to supply regeneration heat. Acid gas content may be 5–35%. Heavy hydrocarbons are easily handled. If no H2S is present, oxygen contents of several percent are handled without difficulty or solvent degradation.
Licensor: UOP LLC