Integrated Systems

A Chart integrated nitrogen rejection unit monetizes low btu gas reserves and provides increased revenue opportunities through the recovery of natural gas liquids (NGL) and helium and the off-take of LNG and liquid nitrogen.

Design Basis Guidelines

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

Superior Design & Engineering

Nitrogen Rejection Unit


Chart is responsible for around 25% of the world's installed NRU database and 50% of the world's name plate capacity.


Vertically integrated design and manufacture of integral Brazed Aluminum Heat Exchangers (BAHX).

One-stop Shop

Process design, detailing and shop fabrication of flange to flange cold box solutions.

NGL Recovery

Incorporating recovery of ethane, propane and heavier hydrocarbons results in significantly reduced equipment costs and lower energy consumption compared to independent nitrogen rejection and NGL recovery units.


Just Another Day

Built and shipped from our New Iberia, LA facility, this Nitrogen Rejection Unit comprises dual cold boxes and processes 900 million scf/day of natural gas.


Technical Library

View and download sales literature, technical manuals and more

Brazed Aluminum Heat Exchangers

Integrated Energy Systems

Nitrogen Rejection Units

Product brochure for Cryogenic Nitrogen Rejection Units.

Holding the Key

Integrated nitrogen rejection units hold the key to unlocking gas processing. First published in Hydrocarbon Engineering in 2016.

LNG Production

Producing LNG as an adjunct to a gas processing facility.

BAHX Installation, Operation, Maintenance Manual (2024)

Connect with Chart

Our global engineering center for nitrogen rejection units is in The Woodlands, TX

Telephone  +1 281 364 8700