Method for separating gases

An apparatus for separating gases containing helium, wherein said apparatus comprises

• a feed stream separation stage, a retentate separation stage, a permeate separation stage, at least one compressor, and/or at least one, vacuum pump, wherein
• the feed stream separation stage is designed such that it 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 is designed to separate 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 is designed to separate 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 apparatus is designed such that the third permeate stream can be removed as a product or processed further and optionally the second retentate stream can be removed as a further product or processed further or discarded, and
• the apparatus is designed such that the second permeate stream and/or the third retentate stream can be fed to the feed stream, and
• the apparatus is designed so that the first permeate stream is not subjected to a recompression, and
• wherein the apparatus is designed with a control such that 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 recycling of the second permeate stream and of the third retentate stream is regulated such that the helium concentration after the first recycling of the second permeate stream and of the third retentate stream in the feed stream is increased compared to the concentration in the crude gas stream.

An apparatus for separating gases containing helium, wherein said apparatus comprises

• a feed stream separation stage, a retentate separation stage, a permeate separation stage, at least one compressor, and/or at least one, vacuum pump, wherein
• the feed stream separation stage is designed such that it 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 is designed to separate 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 is designed to separate 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 apparatus is designed to remove the third permeate stream as product or processed further, and
• the apparatus is designed to feed the second permeate stream to feed stream, and
• the apparatus is designed to remove the second retentate stream as a first further product or processed further or discarded, and
• the apparatus is designed to feed the third retentate stream to the feed stream or discarded, and
• the apparatus is designed so that the first permeate stream is not subjected to a recompression, and
• wherein the apparatus is designed with a control such that upon recycling the second permeate stream and optionally the third retentate stream, the volume of the optionally 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 optionally the third retentate stream, the recycling of the second permeate stream and optionally of the third retentate stream is regulated such that the helium concentration after the first recycling of the second permeate stream and of the third retentate stream in the feed stream is increased compared to the concentration in the crude gas stream.

An apparatus for separating gases containing helium, wherein said apparatus comprises

• a feed stream separation stage, a retentate separation stage, a permeate separation stage, at least one compressor, and/or at least one, vacuum pump, wherein
• the feed stream separation stage is designed such that it 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 is designed to separate 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 is designed to separate 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 apparatus is designed to remove the each of the second retentate stream and the third permeate stream as product or to further process each of the second retentate stream and the third permeate stream, and
• the apparatus is designed to discard the second permeate stream to feed stream, and
• the apparatus is designed to feed or discard the third retentate stream is fed to the feed stream, and
• the apparatus is designed to so that the first permeate stream is not subjected to a recompression, and
• wherein the apparatus is designed with a control such that upon recycling the third retentate stream, the volume of the recycled stream comprises less than 50% by volume of the feed stream after combining with the crude gas stream, and
• wherein upon recycling the third retentate stream, the helium concentration after the first recycling of the third retentate stream in the feed stream is increased compared to the concentration in the crude gas stream by at least 2% compared to the concentration in the crude gas stream.