11th March 2020
From cost savings to consistent purity - the benefits of on-site nitrogen generators are numerous for labs requiring a reliable source of nitrogen gas. A common type of such nitrogen gas generators is one with one or more integrated compressors. But how do compressor-based nitrogen gas generators actually work?
Nitrogen gas Compressor Technology
When a nitrogen generator produces nitrogen gas, the generator does not create nitrogen by itself. Rather, nitrogen gas present in air (roughly 78% of air is nitrogen) is purified inside the generator, as any additional molecules, such as, oxygen, carbon dioxide or water (moisture), are removed from the gas. Once separated from these extra compounds, nitrogen gas can be used for analysis.
Nitrogen compressor technology enables this separation process by providing air to a nitrogen generator system to purify either through a membrane and other filters or through a Pressure Swing Adsorption (PSA) system and filters. This means that a compressor-based nitrogen generator is a standalone solution for labs. – used the word integrated later in this piece, good word to use to describe compressors in the product.
At Peak Scientific, we understand the importance of having a dependable gas supply delivering consistency purity levels 24/7. That’s why we work closely with world-leaders in compressor technology to ensure best-in-class compressor efficiency for optimum purity and results across LC-MS instruments
One way of separating nitrogen gas from air with an internal compressor is through a membrane nitrogen generator, where air is compressed and passed through a membrane consisting of hollow fibres with pores small enough to prevent nitrogen from being pushed through along with oxygen. High purity nitrogen gas is then left behind and is ready to be supplied to the instrument.
There are more advanced nitrogen generators offering multiple filtration stages to further remove dust or moisture before nitrogen gas gets to the membrane. For instance, Peak’s Genius XE nitrogen generator includes a two-stage removal process to eliminate moisture, and a proprietary non-methane hydrocarbon (NMHC) filtration stage to remove long-chain hydrocarbons found in air. Whilst these additional stages of purification and filtration generate higher purity nitrogen gas, they also serve to protect the membrane inside the generator to reduce wear and tear and increase efficiency and output, whilst offering redundancy for backup in the unlikely event one compressor has an issue.
Another nitrogen compressor-based system is the PSA technology. A PSA nitrogen generator, just like a membrane nitrogen generator, also uses an air compressor to supply nitrogen gas from atmospheric air. However, a PSA nitrogen generator then passes nitrogen gas through a column – a Carbon Molecular Sieve (CMS) – which has its surface covered by tightly packed carbon granules which only allow oxygen molecules to adsorb to the carbon material. The nitrogen gas molecules instead pass through the CMS and are filtered by this method.
For a PSA nitrogen generator, two CMS columns are required, where one column is depressurized whilst the other column sends the air through the sieve at pressure. PSA nitrogen generators also include a multistage prefiltration processes to remove dust particles and moisture from air before it reaches the CMS.
With nitrogen compressor systems, it is highly advisable to have regular compressor maintenance performed. A compressor will require a preventative maintenance service once a year in order to maintain output purity and integrity, but also to enhance the life span of the generator, and ultimately protect a lab’s investment. For these gas generators, Peak Scientific offers market leading gas generator service plans for all Peak Scientific gas generators, giving your lab a rapid response time, even in the unlikely event of a product issue. With Pea engineers located throughout the world you can be sure that help is never far away and uptime of your gas generator is at its maximum.
Compressor-based generators have made a huge positive impact on laboratory nitrogen gas supply. All integrated in a single generator system, nitrogen compressor-based generators provide labs with access to nitrogen gas at a consistent purity, thanks to membrane and PSA technologies.
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