Method for separating gases

摘要

The invention relates to a special apparatus, in particular linkage of gas separation membrane modules, and a special method for separating gas mixtures containing helium.

主权项

1. A method for separating gases containing helium, wherein said method
is carried out in an apparatus which comprises a feed stream separation stage, a retentate separation stage and a permeate separation stage, at least one compressor and/or at least one vacuum pump, and the feed stream separation stage separates a feed stream consisting of helium and at least one other component into a first permeate stream enriched with regard to helium compared to the feed stream, and a first retentate stream depleted with regard to helium compared to the feed stream, and the retentate separation stage separates the first retentate stream into a second permeate stream enriched with regard to helium compared to the first retentate stream, and a second retentate stream depleted with regard to helium compared to the first retentate stream, and the permeate separation stage separates the first permeate stream into a third retentate stream depleted with regard to helium compared to the first permeate stream , and a third permeate stream enriched with regard to helium compared to the first permeate stream, and the third permeate stream is removed as product or processed further and optionally the second retentate stream is removed as a first further product or processed further or discarded, and the second permeate stream and/or the third retentate stream is or are fed to the feed stream, and the first permeate stream is not subjected to a recompression, and wherein upon recycling the second permeate stream and the third retentate stream, the volume of the combined recycled stream comprises less than 50% by volume of the feed stream after combining with the crude gas stream, and wherein upon recycling the second permeate stream and the third retentate stream, the helium concentration after the first recycling of the second permeate stream and of the third retentate stream in the feed stream is increased, by at least 2% compared to the concentration in the crude gas stream.