Gas Processing & Vapor RecoveryCleaner and More Revenue

Refrigerated Lean Oil System (RLOS)

Inlet gas enters the bottom of absorber, while lean oil enters the top of the absorber and flows downward making contact in a counter flow fashion over some packing material. The Lean Oil absorbs the vapors from gas stream and becomes Rich Oil. This process leaves mostly methane vapor (C1) behind. Methane is released through the top of the absorber. Special mechanisms are in place to minimize slippage or carry-over of the lean oil. Rich oil goes to the Lean/Rich heat exchanger for exchanging heat with recycled lean oil before entering the Deethanizer. Ethane vapor (C2) flows upward in the column after being heated by the reboiler and goes out of the top of the column. Rich oil containing propane and heavier hydrocarbons (C3+) leaves from the bottom of the Deethanizer and goes to the Stripper column. In this column the rich oil is heated to strip out the propane plus gas vapors (C3, C4, C5,…) absorbed in the rich oil and then the rich oil is recycled back to the lean oil. The vaporized propane and heavier hydrocarbons (C3, C4, C5,…) are liquefied by a condenser and chiller and transferred to storage tanks. Finally the Lean Oil leaves from the bottom of the last Stripper and enters a chiller taking the Lean Oil to its lowest temperature before entering the absorber to start the whole process again. Two more columns, the Depropanizer and the Debutanizer can be added to get further separation. In that case C5+ will be stripped out in the last stripper.

PETROGAS Refrigerated Lean Oil Absorption Systems are designed to operate continuously in a fully automatic mode and the systems are supplied as complete factory packaged units, including instrumentation, piping and electrical, on a structural skid.

The advantages of Lean Oil system

  • Uses proprietary lean oil for absorption of C2+
  • Uses reactive distillation methods for lean oil regeneration and condensate fractionation
  • High C3+ recovery and high turndown
  • Low feed pressure requirements
  • Immune to moisture in the gas
  • Low initial capital cost
  • Lowest operating costs
  • Fully automatic and operates safely unattended
  • Simple installation and operation
  • Reliable and robust
  • Highest production of liquids than any other systems (recovery 95~99%)
  • Mobile skid mounted structure
  • No trapped condensates in the system
  • Minimal slippage and consumption of lean oil