Many common manufacturing processes in metals, aerospace, automotive, medical, silicon, and a range of other industries require an inert environment and use argon to achieve it. The argon used in these processes is very pure, usually 4N or 5N purity (99.99% to 99.999%). At the outlet of the process, the argon is often still present at high concentrations but can be mixed with other impurities, like nitrogen, for example.
Most manufacturers vent this very expensive argon back into the atmosphere and buy it all over again from their gas supplier. After all, there doesn’t seem to be any other option.
On the one hand, they can’t recirculate the argon back into their process because it’s not pure enough anymore, and even if it is at first, they eventually create a snowball effect where the argon becomes less and less pure each time it’s recirculated. This inevitably affects the quality of their product. On the other hand, while distillation is used to extract and purify argon from the atmosphere, it’s not a viable option to re-purify the exhaust argon. A manufacturer would never make their initial capital back, even without incorporating the cost and difficulty to operate the distillation at high efficiency. Nonetheless, venting the high concentration argon in the exhaust network and having to buy it all over again results in enormous waste and cost.
... to continue reading you must be subscribed
