Abstract
Nowadays, gas processing for natural gas liquids (NGLs) recovery is becoming of great interest. However, many of the present NGLs recovery units in operation do not give the desired revenue. This study focuses on the retrofitting of an existing NGLs plant constructed in Egypt for maximizing LPG product recovery due to its high economic value. Various alternatives have been suggested to maximize LPG recovery, while achieving the same cooling target and ethane recovery in terms of power consumption and additional capital cost. The economic study shows that replacing the existing pure propane refrigerant used to recover C5+ (pentane and heavier) in the existing plant by a mixed refrigerant type is the best retrofitting technique. Furthermore, the exergy of the whole NGL unit was studied to evaluate the exergetic performance of all suggested upgrading methods. Regarding the upgraded plant, the butanes and propane recoveries were increased by 13% and 7%, respectively, with 15.95% increase in LPG overall recovery. In addition, the solutions of operational problems that may appear in the glycol injection system, propane refrigeration facilities, and de‐ethanizer unit facilities when switching from single refrigerant to mixed refrigerant have been taken into consideration.