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Nitrogen Rejecton Unit

Nitrogen Rejection Unit

Removing nitrogen from natural gas

A Nitrogen Rejection Unit is used to remove nitrogen from natural gas. Thanks to the proprietary design of its technology, Air Liquide Engineering & Construction offers flexible solutions that cover a wide range of needs, including the ability to treat any natural gas composition, and the capacity to minimize greenhouse gas emissions in the vented nitrogen. In addition, the Air Liquide Group operational feedback allows Air Liquide Engineering & Construction to offer cutting edge technology, and robust design with high efficiency and flexibility.

Efficiency and flexibility

In a Nitrogen Rejection Unit, natural gas containing nitrogen is partially condensed. Methane and nitrogen are then separated in a system composed of one to three distillation columns depending on the feedstock composition and pressure. The process scenario is always selected according to project-specific parameters such as feed evolution with time and product specifications.

Air Liquide Engineering & Construction offers a range of solutions for Nitrogen Rejection Units. The feedstock used for this process can be natural gas, associated gases or unconventional gas sources, and almost any mix of nitrogen and methane (5-90%) can be treated. This proprietary technology delivers high efficiency and flexibility, and generates a sales gas at pipeline specification. Furthermore, greenhouse gas emissions to the atmosphere are kept at a minimum, with less than 1% methane in the nitrogen vent.


  • Purifies natural gas by removing nitrogen
  • Compatible with almost any ratio of nitrogen and methane
  • Very high recovery rates (>99% methane)
  • Optimized investment
  • Proprietary technology offers flexibility
  • Minimal greenhouse gas emissions

Key figures

  • Capacity: up to 1 million Normal cubic meters per hour (Nm³/h)

Nitrogen Rejection Unit