How do membranes concentrate nitrogen from compressed air?
The membrane nitrogen separator uses hollow fibre asymmetric membrane technology to separate and recover nitrogen from compressed air.
The membrane uses the selective permeation principle to produce nitrogen of high purity.
Each gas has a characteristic permeation speed as a function of its ability to dissolve and to pass through a membrane.
The different speed, related to the molecular shape and weight of each element, influences their behaviour through the membrane.
It is like in a car race, where every gas chooses the path that best suits it, or better, the only that suits it.
Oxygen is a “fast” gas (as well as carbon dioxide and water vapour) and is spread selectively through the membrane wall, while the slower nitrogen continue to flow along the inner and smaller part of the fiber creating a high-concentration stream and reaching the outlet of the fibers bundle, where it is collected.
The oxygen-enriched or permeated gas is discharged from the membrane separator at atmospheric pressure. The physical reason for the separation is the difference between the partial pressure of the gas inside the hollow fibre and the external pressure.
There is no need for actuated valves or moving parts. Simplicity and reliability are at the base of this technology, from the installation of the system to the production of nitrogen with its relative maintenance.
What is needed at the inlet of a membrane generator is just clean compressed air at a constant temperature (even wet) and the production can immediately be operative.
Many nitrogen applications require high purity, for inertization or delicate and accurate purposes (like in food or pharmaceutical industry), and membrane can produce nitrogen with a purity up to 99,9 %.
As Sinergia referance list (contact us and we can feed your curiosity) can prove, we have a very big experience and know-how with this technology, for so many various applications, with relative different requirements, from oil&gas fields and facilities, to industries and power-plants.
Keep following Sinergia. Next “technology” article will be about “Nitrogen Generation – PSA Technology”, the big brother of membranes.