METHOD FOR THE SIMULTANEOUS RECOVERY OF A PURE HELIUM AND PURE NITROGEN FRACTION

摘要

A process for simultaneous recovery of a pure helium and a pure nitrogen fraction from a feed stream containing at least methane, nitrogen and helium, is disclosed. The feed stream is partially condensed and separated into a helium-rich gas fraction and a nitrogen- and methane-rich liquid fraction. The helium-rich gas fraction is conveyed to a purification stage in which a pure helium fraction is recovered by adsorption, permeation and/or rectification. At least one partial stream of the nitrogen- and methane-rich liquid fraction is taken to a rectification process for recovery of a pure nitrogen fraction.