SF6 reclaimer from SF6/N2 mixtures by gas separation with molecular sieving effect

This paper discusses the various methods for sulfur hexafluoride (SF₆) separation from a mixture of low concentrations of SF₆ in N₂ pressure swing adsorption (PSA) with a suitable kind of synthetic zeolite, which has the expected molecular sieving effect. This molecular sieving effect, derived from molecular size difference between SF₆ and N₂, is confirmed by the difference between two equivalent volumes filled with SF₆ and N₂. Prototype equipment of SF₆ separation and liquefaction, that is about 1 m cube in size and 150 kg in weight, has been assembled and tested. The ability of gas mixture handling is 13 l/min on average, and the SF₆ content is reduced to 0.0% (undetectable level) in separated N₂ to exhaust into the atmosphere.