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