Talkin' 'bout nitrogen generation

As an inert gas, nitrogen will displace oxygen from a product or process and can be used to prevent oxidation, stop bacteriological growth and reduce the risk of combustion and explosion. 

This can help with eliminating product spoilage in food and beverage applications, ensuring safety standards are maintained in pharmaceutical production and minimising contamination in chemical processing, to name a few.

Manufacturing and analytical equipment can be purged with nitrogen gas to remove oxygen and water vapour from process lines, which can increase product quality and reduce the need for further conditioning treatments.

Harsh oil and gas environments are also familiar with the uses of nitrogen, where it is not only used to suppress oxygen and thereby remove a potential fire hazard but also for a wide variety of other applications including blanketing, purging and sealing. 

Supply and demand

Typically, operators will purchase the nitrogen they require from a supplier, either as gas in small high-pressure cylinders or in liquid form, stored either in mini-tanks or in bulk storage vessels. With up to 97% of global nitrogen supply fulfilled by traditional gas companies, it is clear that there is growing demand.

However, obtaining and maintaining a ready supply of nitrogen is not without its drawbacks. As well as finding a reliable vendor and arranging deliveries and payment, companies require sufficient space to store the gas alongside a thorough procedure to monitor and manage the supply safely.

This is where the installation of an on-site nitrogen generation system, such as Gardner Denver’s nitrogen generators, can pay dividends, providing operators with on-demand supply and complete control over the volume and flow of the gas required.

The system converts compressed air in to guaranteed-purity nitrogen. Pre-treated air from a standard industrial compressor is ‘sieved’ using carbon molecular technology to remove all oxygen and other trace gases, leaving the nitrogen to pass through to the application.

The system can reduce supply costs by as much as 90% with payback in less than two years for a company using liquid nitrogen or as little as one year where gas cylinders are being used.

Key considerations

Operators considering investing in an on-site nitrogen generation system have a number of factors to consider.  The first of these is the purity of the gas, as each application demands different quality levels depending on whether the gas comes into direct contact with a food or pharmaceutical product, or indirectly to form packaging or for general blanketing.

It is advisable to select a generator that can offer a flexible range of purity levels, to avoid the time and expense of commissioning a completely bespoke package.  Gardner Denver’s range for example provides purity levels from 5% to 5ppm remaining oxygen content, and features an integral oxygen analyser for continuous purity monitoring.

Site limitations, particularly around available floor space and installation costs should also be taken in to account to avoid any expensive civil engineering works.  Operators should also ensure easy integration with existing compressor installations to minimise capital expenditure.

Flow rate should be matched accurately to the application requirements, so that the required amount of nitrogen is being generated.  This will help to improve efficiency while also ensuring that sufficient gas is always available, maximising production uptime.

Energy consumption is a major consideration in the purchase of any new plant equipment and typically, an on-site system will use significantly less energy to generate the nitrogen required on-site than it takes for a supplier to produce and deliver the same amount.