CNS Arabia

Technology of Membrane

What Is Membrane Air Separation Technology?

  • A technology used to generate Non-cryogenic (gaseous) Nitrogen on-site.
  • A polymeric hollow fiber selectively permeates oxygen, water vapor, and other impurities out of its side walls while allowing Nitrogen to flow through its center and Emerge as product.
  • Thousands of hollow fibers are bundled and encased to form a high performance gas separation module.

Click to view animation of the Nitrogen Generation Process.

Nitrogen Generator Components


The NGU uses a twin screw compressor. The compressor draws ambient air and delivers pressurized after cooled air to a series of water, oil and particulate filters, and separators. Cleaned dry air passes through air separation Membranes producing high purity nitrogen. The nitrogen gas passes through metering and flow devices before entering a reciprocating booster. The booster increases the nitrogen gas pressure for final discharge out the side of the truck.

On board generator

The generator produces 120 Vac, 60 Hz, 1 phase @ 41 Amps. The diesel driven motor is fueled from the main fuel tank.


The compressor is a rotary screw type delivering after cooled feed air. It compresses air to approximately 365 psig @ 1250 scfm (25 bar @ 35 sm3/min) for delivery.

Control Cab

The control cab has the control panels for the compressor, Membrane module and booster.

Hollow Fibers

“Membrane” Separation of nitrogen from the air by selective permeation through a bundle of hollow fibers. Nitrogen Membrane separators removing oxygen, carbon dioxide and other trace gases, resulting in high purity Nitrogen.


The booster increases the nitrogen gas pressure for final discharge out the side of the truck, The three stage reciprocating booster delivers up to 700 SCFM @ 4000 psig (20 SM NITROGEN GENERATING UNIT 700-HPNGU-95-4000/min @ 276 bar) with a 300 - 330 psig (21 - 23 bar) input.

Secondary after cooler

The cooler is a second aftercooler between the compressor and the filters. The three fans (electrical) on the aftercooler are controlled (on/off) by the aftercooler inlet temperature.