Nitrogen Rejection Unit (NRU) Calculator

About Nitrogen Rejection

NRUs remove excess nitrogen from natural gas to meet pipeline specifications (typically N₂ < 4%) and improve heating value. Cryogenic distillation is preferred for high-purity, high-volume applications.

Technology Selection

• Cryogenic: > 95% CH₄ recovery; >20 MMSCFD; high N₂ (>10%)
• PSA: 90-93% recovery; moderate volume; simpler operation
• Membrane: Membrane Separation Calculator →

Key Design Parameters

• Relative volatility (α): 2.0-3.0 typical at -220 to -260°F
• Column stages: 30-60 theoretical stages
• Feed purity: < 0.1 ppm H₂O, < 50 ppm CO₂
• BAHX approach: 3-5°F at cold end