Nitrogen Rejection Units (NRU)

Monetization of low btu gas reserves and technology solutions for maximized revenue via nitrogen rejection with integrated helium recovery, NGL extraction, LNG and/or LIN production.

Nitrogen Rejection Nitrogen Rejection Nitrogen Rejection
Nitrogen Rejection Nitrogen Rejection Nitrogen Rejection

Cryogenic NRU offers the highest methane recovery rates and is standard practice for plants >15 MMSCFD. A Chart integrated nitrogen rejection unit is the ideal solution for the monetization of low btu gas reserves and increased revenue opportunities through the recovery of natural gas liquids (NGL) and helium and the off-take of LNG and liquid nitrogen.

Why Chart?

  • Extensive, proven and demonstrative worldwide NRU experience 
  • Vertically integrated design and manufacture of integral Brazed Aluminum Heat Exchangers (BAHX)
  • Process design, detailing and shop fabrication of flange to flange cold box solutions 
  • Gas monetization opportunities via integrated process design
  • NRU solutions from 15MMSCFD to >900MMSCFD of feed gas
  • Inlet nitrogen concentrations from 1% to >70% processed to monetize low btu gas

Nitrogen Rejection Unit

Design Basis Guidelines

5 features of a Chart Industries Nitrogen Rejection Unit

Single low pressure column NRU

  • Generally applicable to an inlet nitrogen concentration >40%

Single high pressure column NRU

  • Generally applicable to inlet flows <30 MMSCFD and without integrated helium recovery

Two (or more) Column NRU
Where inlet nitrogen concentrations are <40% and/or integrated helium recovery is required Chart’s patented and proven pre-fractionator nitrogen rejection technology is the optimum processing solution. The resultant two column design features a pre-fractionator followed by a low pressure NRU fractionator and offers the following:

  • Conditions very low nitrogen concentration inlet gases for efficient separation and minimized methane losses
  • Recovery of a substantial fraction of methane at elevated pressure reduces recompression horsepower
  • Permits higher concentrations of CO2 and C4+ hydrocarbons in the inlet feed
  • Permits high recovery of crude helium