With nitrogen making up 78% of the environment (the air we breathe), and freely available, it’s not surprising more and more manufacturers are investing in innovative systems so they can generate their own nitrogen on-site, based on demand, purity and quality requirements.
Manufacturers involved with laser cutting, injection moulding and heat treatment, as well as several other manufacturing applications, are reaping the significant benefits of having continuous availability of dry nitrogen, which is mainly used to displace oxidation-causing oxygen.
Instead of relying on the costly and timely process of using nitrogen bottled gas supply (bottle banks) or bulk gas supplied in either gaseous or liquid form and stored on site in large tanks, manufacturers are moving to a more reliable and environmentally friendly system, and in the process considerable reducing their production costs.
Sonik Barot, Atlas Copco Australia’s Product Manager for CNG & Industrial Gas Projects, said the company’s energy efficient on-site nitrogen generation systems are generating considerable interest as manufacturers search for new ways to improve their production efficiencies and reduce operating costs at the same time.
“It is not surprising manufacturers are taking notice of our all-in-one nitrogen skids as they offer savings of 40 to 80% compared to existing nitrogen supply costs from bottled or bulk gas supply,” he said.
Barot highlights the fact that bottled and bulk nitrogen gas supply prices are normally between $5 to $17 per m3 based on the purity and the supply terms negotiated.
“However with our on-site nitrogen skid based system, generation costs work out to be less than $3 per m3 in most cases, with payback normally within 18 to 24 months.”
He pointed out that once paid for, electrical and maintenance costs were the only operational expenditure; offering savings of more than 80% compared to traditional nitrogen supply from bottled or bulk gas supply.
“Once companies look at the figures, it’s an easy decision for them from a financial and reliability perspective. Plus of course they are lowering their environmental impact as well. A win-win situation,” he said.
Barot explained that the Atlas Copco Nitrogen Skid comes with the company’s highly-efficient GA VSD+ compressor, an NGP+ nitrogen generator using the latest generation PSA (Pressure Swing Adsorption) technology, air and nitrogen receivers, a booster, dryers and filters, all integrated into one compact and pre-commissioned skid.
“It is a true plug-and-play solution, which drastically reduces installation time and costs, and delivers cost savings and nitrogen supply independence for complete peace of mind,” he said.
“We are the only company which can offer the complete package mounted on just one small footprint skid; saving valuable floor space at the customer’s site.”
He said all components are built to Atlas Copco quality and energy efficiency standards, and are tested to work together for optimal performance and reliability.
Barot explained that the PSA nitrogen generators are used to separate nitrogen molecules from other molecules in the compressed air with oxygen, CO2, water vapour and other gases adsorbed and released back to the atmosphere.
“The result is virtually pure nitrogen at the outlet of the generator,” he said.
With an air factor of 1.8 (at 95% purity) to 5.5 (at 99.999% purity) and a special cycle time modulation algorithm, Mr Barot said the running costs of the new NGP+ can be 50% lower compared to other nitrogen generators.
There are eight models available; four 40-bar versions for direct use and four 300-bar versions that also allow users to fill the skid-mounted storage tank or cylinders to create their own supply to their nitrogen process gas network.
”They can serve as the users’ nitrogen back-up supply, but they also allow users to downsize their system in case of fluctuating demand,“ Barot said.
Barot said that by catering to peak requirements with the user’s own pre-filled bottles, rather than with a higher capacity generation system, it offers significant savings.
He said the nitrogen skids are available in various capacity models, delivering from 6 to 60Nm3/hour at 99.9% purity and 4 to 38Nm3/hour at 99.999% purity.
“For larger companies, with higher capacity requirements, Atlas Copco can custom design and build a customised nitrogen generation system as per their needs and requirement,” he said.
Recognising that the nitrogen purity required varies from application to application, Barot said the purity of the nitrogen produced by the system can be easily adjusted to suit the company’s needs, from 95% to 99.999% or 5000ppm to 10ppm
“In laser cutting, for example, the higher the purity the cleaner the cut, with no burrs and no oxidation taking place,” he said.
He said it’s a similar story with the plastics industry.
“Operating the injection moulding machines at a high purity and the high pressure nitrogen delivers a far better finish, very clean with no burrs. Like laser cutting there is no oxidation with high purity nitrogen,” he said.
He explained that the nitrogen skid package comes standard with an oxygen analyser to measure the oxygen molecules and confirm the purity levels.
“If there is a problem with the nitrogen’s purity, all the gas generated is simply released into the atmosphere,” Barot said.