Use refrigeration to boost liquids recovery from LPG-rich gas

M. Hani, Energy Enterprise Associates, Karachi, Pakistan Technology is improving day by day to increase the profitability of gas processing plants. The LPG recovery unit plays a vital role in boosting revenue by increasing liquids recovery from the feed gas. Turboexpander technology with an absorber column is conventionally used for >99% propane recovery in many licensed processes, with several variations. A turboexpander reduces the pressure of the inlet gas to the outlet pressure, and it produces a cryogenic temperature, which aids in the recovery of NGL and LPG from the feed gas stream to meet hydrocarbon dewpoint specifications. Fig. 1 shows a schematic of the LPG recovery unit.