NITROGEN GENERATION

Nitrogen Generators come in two designs, PSA (Pressure Swing Adsorption) and Permeation Membrane Systems, both are unique in design, operation, complexity, and service requirements.

PSA (Pressure Swing Adsorption) System;

How PSA Nitrogen Generation Works

Ad-sorption is the physical process of separating molecules. Pressure Swing Adsorption (PSA) systems generate nitrogen, by separating it from the oxygen in ordinary air.

A vessel containing carbon molecular sieve, or CMS, is filled with compressed air.  While under pressure the smaller oxygen molecules are adsorbed by the sieve material while the larger nitrogen molecules drift past and are collected in a nitrogen receiver.

 

Pressure is then released from the vessel, and the oxygen molecules are vented to the atmosphere. While the depressurization is occurring, the cycle is repeated in a second vessel.  The process is repeated swinging from one vessel to another for as long as there is a nitrogen demand.

Permeation Membrane Systems;

How a Nitrogen Generator Membrane Works

Pressurized air is fed to one end of the hollow fiber membranes. Membranes contain a bundle of hollow fibers with holes small enough to allow the smaller oxygen molecules to exit through them under pressure. The permeation rates of water vapor, CO2, and oxygen contained in the air stream are faster than nitrogen and argon and will rapidly diffuse through the fiber walls. The slower diffused nitrogen molecules remain in the fiber bore and are collected as the nitrogen product gas. The air flow rate will determine how much undiffused oxygen remains with the nitrogen gas. The nitrogen product gas is extremely dry, with atmospheric dew points typically below -40°F. The membranes act like a filter with no moving parts and continuously generate nitrogen at selected flow and purity.