Nitrogen generator, nitrogen purification, PSA, membrane, air.

Nitrogen generator
Crystec Technology Trading GmbH

Nitrogen generators for the production of high purity nitrogen (N2) from air

Nitrogen is required for various industrial processes. The Haber-Bosch process for the synthesis of ammonia and the production of calcium cyanamide are the most important examples. The use as a protective gas is also a commen application. This is used to prevent fire, explosion, corrosion or unstable chemical syntheses. Nitrogen can either be purchased directly in gas containers or generated by a gas generator. The on-site purification of air to nitrogen offers several advantages:

There are two different systems for nitrogen generators. One is the pressure swing adsorption generator (PSA) and the other one is a membrane generator.

PSA-Nitrogen-Generator

So-called Pressure Swing Adsorption (PSA) is used to remove oxygen and therefore seperate nitrogen (N2) from the air. This is based on a physical process that makes use of the different adsorption properties of different gases at differend pressure levels in order to separate them. Depending on the implementation, it is also possible to separate other gases such as carbon dioxide. Oxygen-affine materials such as carbon molecular sieves (CMS) are used to remove oxygen and generate high-purity nitrogen. The gas mixture (air) flows at a certain pressure into the molecular sieve designed for this application. Due to the stronger interaction of oxygen with the molecular sieve, it accumulates here. The second gas (nitrogen) on the other hand is not adsorbed and thus leaves the generator enriched. After the molecular sieve has reached its capacity limit, the gas flow is diverted to another molecular sieve. The first molecular sieve can be regenerated through pressure reduction using the associated significantly weaker interaction between the molecular sieve and oxygen. After this, it is available for purification, again. The system is controlled by a program logic control (PLC). This allows continuous purification to be achieved.

Nitrogen PSA-Gas-Generator (SinceGas)
  • Stable gas generation using a semi-continuous process
  • Fully automatic system
  • Small footprint and easy operation: The system is operated from the front.
  • The cracker is characterized by its low power consumption and operating costs.
  • Implementation and design can be adapted within certain limits according to customer requirements
  • Depending on the design, purities up to 99.9995% can be realized
  • Depending on the design a gas flow of 3-5500 N m3/h can be realized
  • Full CE Certification

Stickstoffgenerator PSA

Nitrogen-Membrane-Generator

Unlike pressure swing adsorption, a membrane generator uses polymer hollow fiber membranes to primarily remove oxygen from the gas flow. The separation of nitrogen and oxygen takes place in the membrane separators. These always consist of a bundle of the above-mentioned hollow fibers and are gathered in a cylindrical shell. Based on the selective pass through and therefore different strong interactions of the gases with the hollow fiber, these can be separated. Each gas has a characteristic penetration rate. So there exists "fast" gas like oxygen and "slow" gas like nitrogen. By applying a pressure difference between the compressed inlet gas and low pressures behind the membrane, dry compressed air is selectively transferred through the membrane wall. As nitrogen migrates along the inside of the fiber and thus can form a nitrogen-rich product stream, oxygen emerges quickly from the fiber again and can therefore be vented at atmospheric pressure.
A nitrogen membrane generator is always made up of several hollow fiber bundles and offers a simple solution for generating nitrogen gas.

Nitrogen-Membrane-Gas-Generator (SinceGas)
  • Stable gas generation using a continuous process
  • Small footprint, easy operation: Operation switch installed on front panel.
  • The cracker is characterized by its low power consumption and operating costs.
  • Almost no start-up times necessary
  • Implementation and design can be adapted within certain limits according to customer requirements
  • Depending on the design, purities of up to 99.9% will be realized
  • Depending on the design a gas flow of 3-5000 N m3/h can be realized
  • Full CE Certification

Stickstoffgeneraor, Membrangenerator

Comparison of PSA generator and nitrogen membrane generator

PSA-Generator Nitrogen-Membrane-Generator
  • very high purity up to 99.9995% easy to implement
  • high efficiency
  • short start-up time
  • moderate requirements for input gas
  • low maintenance costs
  • purity up to 99,9% possible
  • Purity depends on pressure and gas flow
  • very short start-up time of the generator
  • very low maintenance costs
  • low weight and space requirement

Crystec will be pleased to engineer a cost effective system to satisfy your most demanding and exacting requirements.