Nitrogen generators

Nitrogen is a gas that does not react with other elements (an inert gas), does not support combustion and has no smell, colour or taste, which makes it suitable for a very wide range of applications: from various processes in chemical manufacture, through the processing industry, to handling, storage and delivery.

Nitrogen has very low reactivity and is ideal for “blanketing” products, and is often used as a purging gas as well. It can be used to remove contaminants from process streams in stripping and injection methods. Thanks to its properties it can be used to protect products from harmful elements. Being inert, it also allows flammable ingredients to be stored and used safely, and can help prevent explosions of combustible dusts.

A nitrogen generator separates nitrogen from compressed air at the point of use, removing the costs of buying, transporting and storing cylinders. The purity is set according to the application and directly affects the air consumption per cubic metre of nitrogen.

In the wine, juice, dairy and water industries, nitrogen is used to prevent products spoiling by blanketing their surface. The nitrogen purity required in these applications is 99 – 99.9%.

In the food industry, nitrogen is used for packaging in a protective atmosphere, where packing is completed by blowing in nitrogen, so products stay fresh longer and their aroma and smell remain almost unchanged from the moment the pack is sealed. The nitrogen purity required in such applications is 95 – 99.99%.

Nitrogen is also used for modified atmosphere packaging, in MAP processes, which keeps products fresh for longer and preserves the authenticity of their natural aromas and flavours. The nitrogen purity required in MAP applications is 95 – 99.5%.

In industrial applications, nitrogen is used to ensure process stability, quality stability and safety. It is therefore used in the electronics industry, in laser cutting, in assisted injection moulding, and for safety in potentially flammable and explosive areas. The nitrogen purity required in these applications ranges from 95 to 99.9999%.

1. By membrane separation, where the maximum achievable nitrogen purity is 90 – 99.5% and the maximum capacity is up to 1,000 m³/h. This is medium to lower purity nitrogen and can be used in applications that do not demand high purity. Low capital outlay; low to medium nitrogen purity.

2. By pressure swing adsorption (PSA), where the maximum achievable nitrogen purity is 90 – 99.5% and the maximum capacity is up to 10,000 m³/h. An affordable investment with a fast return; medium to high nitrogen purity.

3. By cryogenic technology, which yields the purest nitrogen, up to 99.9999%, but this technology requires enormous, costly investment and a large footprint, and is therefore economical only for the professional production and sale of liquid nitrogen in large quantities.

In industrial applications, where nitrogen consumption is constant over time, a PSA (pressure swing adsorption) nitrogen generation system is the ideal solution. Producing nitrogen with your own generator works by separating oxygen from compressed air in the quantity and purity your process requires. The size of the PSA nitrogen generator is matched to the actual nitrogen consumption in your plant, and production is most economical when the unit runs at or close to full consumption capacity.

An example of good practice: a plant for in-house nitrogen production used in coffee packaging; client GRAND PROM, Šimanovci. The client’s requirement was controlled production of 260 m³/h of nitrogen at 99.9% purity, with the emphasis on constant, sustainable purity throughout the year in all ambient conditions.