A process comprising: subjecting a process gas containing NOx to a stage for absorption of NOx in a suitable absorption means, obtaining nitric acid and a tail gas containing nitrogen, argon and residual NOx; subjecting said tail gas to a treatment which comprises at least one NOx removal stage, obtaining a conditioned tail gas; subjecting at least a portion of said conditioned tail gas to a separation treatment, obtaining a product stream containing argon and a product stream containing nitrogen.

A process comprising: subjecting a process gas containing NOx to a stage for absorption of NOx in a suitable absorption means, obtaining nitric acid and a tail gas containing nitrogen, argon and residual NOx; subjecting said tail gas to a treatment which comprises at least one NOx removal stage, obtaining a conditioned tail gas; subjecting at least a portion of said conditioned tail gas to a separation treatment, obtaining a product stream containing argon and a product stream containing nitrogen.

The invention relates to a gas purifier that removes moisture and oxygen from inert gases and reducing gases, for example, at sub-atmospheric pressures. The purifier can remove part per million levels of moisture in a gas stream to less than 100 parts per trillion by volume, and has a low pressure drop and a sharp breakthrough curve.

The invention relates to a gas purifier that removes moisture and oxygen from inert gases and reducing gases, for example, at sub-atmospheric pressures. The purifier can remove part per million levels of moisture in a gas stream to less than 100 parts per trillion by volume, and has a low pressure drop and a sharp breakthrough curve.

The invention relates to a gas purifier that removes moisture and oxygen from inert gases and reducing gases, for example, at sub-atmospheric pressures. The purifier can remove part per million levels of moisture in a gas stream to less than 100 parts per trillion by volume, and has a low pressure drop and a sharp breakthrough curve.