A global speciality chemicals company has nearly halved its nigtrogen gas costs by introducing domnick hunter on-site gas generation technology being adopted by leading Australian companies.
Arch Chemicals BV, with chemical processing sites in more than 20 countries, has adopted at its Dublin copper and zinc omadine manufacturing facility the same MAXIGAS continuous on-site gas generation technology used in Australasia by industry leaders including De Bortoli, Fonterra, Terraharvest, and Portavin.
The omadine biocides produced by Arch are used in market-leading marine antifouling paints and as an anti-dandruff ingredient in popular shampoo brands. Arch relies on nitrogent to blanket Zyline, a highly flammable substance that is a key component during the manufacturing process. Inert nitrogen prevents oxygen coming into contact with flammable substances. It is also used to purge equipment.
After installing a trial MAXIGAS unit, the company concluded it could achieve substantial cost savings and still maintain nitrogen quality by using the reliable domnick hunter pressure swing technology, which extracts nitrogen from ordinary compressed air.
Arch installed an N2MAX112 unit supplying nitrogen gas at a purity of 99 per cent which, achieved considerable economies
In addition to the cost savings, Arch has also benefited from space-saving after the removal of its bulk liquid nitrogen tank. A small multi-cylinder pack has been installed to provide an emergency backup gas supply in the unlikely event of generator failure.
Being introduced to Australia as part of a global launch by domnick hunter (which operates in more than 80 countries) MAXIGAS generators are a proven technology, having been used in more than 10,000 installations worldwide.
MAXIGAS operates on the pressure swing adsorption (PSA) principle to separate larger nitrogen molecules from the air stream. This domnick hunter MAXIGAS nitrogen generation system - which can be set to supply nitrogen from 97% to 10 parts per million (99.999%) - incorporates a self-regeneration feature to minimise maintenance.
MAXIGAS units are constructed in pairs of extruded aluminium columns filled with carbon molecular sieve (CMS) material. Operating on the pressure swing adsorption principle (PSA), the two columns function alternately, with one side producing gas while the other regenerates itself.
The side of the unit being pressurised by compressed air produces a continuous stream of nitrogen, which passes through the CMS while oxygen and other trace cases are adsorbed by it.
The carbon molecular sieve differs from ordinary activated carbons in that it has a much narrower range of pore openings. This allows smaller molecules such as oxygen to penetrate the pores and be separated from the air stream. The larger molecules of nitrogen bypass the CMS and emerge as high purity gas. Purities are determined by the velocity at which the air passes through the CMS columns.
At a pre-set time, before the online bed is saturated with adsorbed gases, the system switches to regenerative mode, venting the contaminants from the CMS. As this happens, the second CMS bed comes online and takes over the separation process to ensure uninterrupted nitrogen production. An in-built oxygen analyser with alarm function ensures only gas of the required purity is delivered to the storage vessel.
Mr Davis says this CMS technology is state-of-the-art for purity of on-site gas production, and is largely maintenance-free in operation, provided it is protected against water, oil and oily gas vapours, which are the enemy of sieve and membrane technology alike.
Installation is simple and proven at applications such as Arch Chemicals. The MAXIGAS design means that if users want more gas, they simply add extra banks of generators. With this system, nitrogen is available on-demand 24/7 without the risk of nitrogen supply failures holding up production, says Mr Davis.