PSA Nitrogen Plant
Nitrogengenerators and stations arestationaryor mobileair-to- nitrogen production complexes.PRESSURE: The technology of air-to-nitrogen production with the use of adsorption processes in nitrogen generators is well studied and widely applied at industrial facilities for the recovery of high-purity nitrogen.
SWING: The operating principle of a nitrogen generator utilizing the adsorption technology is based upon the dependence of the adsorption rates featured by various gas mixture components up on pressure and temperature factors.Among nitrogen adsorption plants of various types, pressure swing adsorption (PSA) plants have found the broadest application world-wide.
ADSORPTION: The system's design is based on the regulation of gas adsorption and adsorbent regeneration by means of changing pressures in two adsorber–adsorbent-containing vessels. This process requires constant temperature,close to ambient.With this process,nitrogen is produced by the plant at the above-atmospheric pressure, while the adsorbent regeneration is accomplished at below-atmospheric pressure.
At the adsorption stage oxygen,H2O and CO2 molecules diffuse into the porestructure of the adsorbent whilst the nitrogen molecules are allowed to travel through the adsorber–adsorbent-containingvessel.
Advantages
Economic benefits: By substitution of cryogenicor adsorption systems nitrogen production savings generally exceed 50%.The net cost of nitrogen produced by nitrogen complexes is significantly less than the cost of cylinde or liquefied nitrogen
Module design:With respect to the simplicity of the system,anitrogen generator can be split into modules.This is indirect contrast to classical systems where the equipment is designed for a certain stage of the separation process.Using amodular system,the generation facility may be built from a selection of preexisting equipmentand where necessary,the output capacity ofa plantmay be increased atthe minimum cost.This option appears all the more useful where a project envisages a subsequent increase in enterprise capacity, or where demand may simply require on site production of nitrogen by employing equipment that is already present.
Dependability:Gas separation units have no moving component parts, thus ensuring exceptional reliability.Membranes are highly resistantto vibration and shocks,chemically inert to greases, moisture-insensitive, and capable of operating over a wide temperature rangeof–40°С to+60°С.With appropriate maintenance,membrane unit useful liferanges between 130,000 and 180,000 hours (15 to 20 years of continuous operation).
Disadvantages
1. Limited capacity
2. Relatively low purity compared to PSA units(95% to 99% purity as compared to 99.9995%- higher purity applications are available at lower flow rates ≤ 10L/min)