Nitrogen generators cut costs of food packaging

Phil Green, at Parker Hannifin's industrial division, explains how the latest nitrogen-generation technology can help food and beverage companies increase their operational efficiency and cut costs.

Nitrogen is used in food-and-drink manufacturing, processing and packaging for a range of industrial applications, from modified-atmosphere packaging for perishable-food products to blanketing alcoholic drinks to prevent oxidation.

However, while nitrogen is all around us, making up 78 per cent of the air we breathe, obtaining a ready supply of the gas can be problematic and expensive.

Typically, food and beverage businesses use supply methods such as high-pressure cylinders, liquid mini tanks or bulk-storage vessels.

Each of these options introduces a range of problems that need to be solved.

There is the need to source a reliable supplier, set aside valuable space in or outside the company's premises and install and maintain the network of pipe-work.

The cost of addressing these logistical issues can be high and difficult to budget for, while the price of gas and supplier rates are changing continually.

One potential solution lies in a new range of gas-generation systems that enable users to produce their own supply of nitrogen onsite.

As a result, companies can generate as much or as little nitrogen as they need, at a fraction of the cost of having the gas delivered by an external supplier.

These integrated systems, such as the Midigas and Maxigas ranges from Parker Hannifin, use a principle known as pressure swing adsorption (PSA) to produce a continuous stream of nitrogen.

Pre-treated air from a standard industrial compressor is essentially 'sieved' so that oxygen and other trace gases are adsorbed while nitrogen is allowed to pass through.

While using a carbon molecular sieve (CMS) for air separation is not a new idea, the radical design and control system employed on these latest nitrogen generators has maximised gas output and reduced compressed-air consumption to achieve even higher levels of efficiency than were previously achievable.

Being able to control the nitrogen supply in this way, as opposed to having to rely on a third party, can reduce costs considerably.

Unlike cylinders, liquid mini-tanks and bulk-storage vessels - which present rental, refill, delivery, environmental levy and order-processing costs - once a nitrogen-generation system has been purchased, the ongoing costs can be reduced by more than 90 per cent when compared with traditional methods of supply.

If a company using liquid nitrogen was to switch to gas-generation technology, it could expect the new system to pay for itself in less than two years, while for a company using cylinders, the payback period could be even sooner - less than 12 months in many cases.

In addition to the cost benefits, nitrogen-generation units offer a more convenient solution than sourcing gas externally and storing it onsite.

The latest compact systems can be installed quickly, easily and at minimum cost and disruption, simply requiring a pre-treated compressed-air stream to start producing nitrogen.

With no need to transport or contain the gas, the environmental impact of using nitrogen for industrial processes can be minimised, while the new systems can also make the workplace considerably safer for employees, eliminating the safety risks of storing, handling and changing heavy high-pressure cylinders.

Generating its own nitrogen on-site puts a food or beverage company in control of its gas supply, producing as much or as little gas as needed and at a consistent, measurable cost.

This more-efficient nitrogen supply is a flexible solution to a company's changing gas needs, as the modular design of the latest systems means that extra banks can be added as required at minimum cost.

Furthermore, to guarantee 100 per cent back up and secure the supply when routine maintenance on one set of systems is required, additional banks of units can be quickly and easily setup onsite.

A large US-based coffee packager that was using nitrogen delivered in liquid form to displace the oxygen in its packs of coffee and prolong shelf life decided to install banks of nitrogen-generation units at its site.

The improvements were immediate; the company no longer needed to worry about late deliveries, fluctuating prices, de-icing the evaporator or signing long-term supply contracts.

Most importantly, the company expects to save more than USD100,000 per year after a payback period of four years.

With the system providing a service life of more than 15 years, the cost savings should be substantial.

By eliminating the problems and costs associated with sourcing nitrogen from an external supplier and storing it onsite, companies can achieve a considerably more reliable, efficient and affordable source of gas for a wide range of applications.

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