The patented AET Process NGL Recovery Unit technology utilizes propane-refrigerationbased absorption to recover C2+ or C3+ NGLs from natural gas streams.
The absorbed NGLs in the rich solvent from the bottom of the NGL absorber column are fractionated in the solvent regenerator column, which separates NGLs overhead and lean solvent at the bottom. After heat recuperation, the lean solvent is presaturated with absorber overhead gases. The chilled solvent flows into the top of the absorber column. The separated gases from the presaturator separator form the pipeline sales gas.
Operating conditions: Wide operating pressure range: 200 to 1,200 psig feeds without inlet gas compression. Inexpensive metallurgy: Lowest temperature, limited by C3 refrigeration, permits the use of predominantly carbon steel metallurgy. Feed pretreatment: CO2 removal is not necessary, and glycol injection for dehydration is adequate. The AET NGL plant uses lighter (70 MW to 90 MW) lean oils. For most applications, there are no solvent makeup requirements.
Economics: Low capital and operating costs: The initial and on-going costs are lower when flexibility for ethane recovery or rejection is important. High ethane recoveries: One pass ethane recovery typically exceeds 96+%. NGL component flexibility: Online switching, from 96+% C2 and 99+% C3 to <2% C2 and 98+% C3, with simple controls. Upgrading simple refrigeration plants: Add-on unit enhances propane recoveries, from typical 30–55% to 96+%, by processing cold separator gases. Depending upon the economics of ethane recovery, the operation of the AET NGL plant can be switched online from ethane plus recovery to propane plus recovery without affecting the propane recovery levels. Licensor: Advanced Extraction Technologies, Inc.,