A method of purifying a gas composed of a product gas and one or more impurity gases including combining a feed stream with a second stream thereby forming a combined feed stream, introducing the combined feed stream into a pressure swing adsorption device, thereby producing a high purity product gas stream and an off-gas stream, and introducing the off-gas stream into a membrane separation device, thereby producing a gas stream lean in product gas and a permeate stream.

A method and system for purification of helium and CO.sub.2 from a stream containing at least Helium, CO2, nitrogen or methane uses a combination of cryogenic, membrane and adsorption technologies.

A method for recovering a helium product or intermediate product, wherein a first natural gas stream containing helium is supplied to a first natural gas processing unit and at least one second natural gas stream containing helium is supplied to at least one second natural gas processing unit, at least the first natural gas processing unit comprising helium recovery means via which the helium product is formed from at least a part of the first natural gas stream. At least temporarily a helium transfer from the at least one second natural gas stream to the first natural gas stream by means of a helium transfer arrangement comprising a membrane unit is performed before the first natural gas stream is provided to the first natural gas processing unit and before the at least one second natural gas stream is provided to the at least one second natural gas processing unit.

The present disclosure relates to a cross-linked thermally rearranged polymer membrane and a method for preparing the same. The cross-linked thermally rearranged polymer membrane prepared according to the present disclosure has fluorine atoms distributed in a cross-linked thermally rearranged polymer membrane so as to have a concentration gradient from the surface and is formed into a three-layer structure consisting of a fluorine deposition layer, a transition layer and a thermally rearranged polymer base layer, thereby having remarkably increased selectivity as compared to the existing commercialized gas separation membrane and, particularly, enabling helium to be separated with high purity and recovery rate from a natural gas well, etc. even with a small membrane area, and thus being commercializable.

Method for operating an adsorber arrangement comprising a first and a second adsorber device, arranged in parallel between an upstream process device providing a process gas and a downstream process device receiving a purified process gas. The method comprising during a process of purifying the process gas with the first adsorber device, cooling the second adsorber device by passing a portion of purified process gas, received from the first adsorber device, through the second adsorber device; and directing the process gas portion that has passed through the second adsorber device to the upstream process device. Then, the first and the second adsorber devices are sequentially coupled, such that process gas from the upstream process device passes through the second adsorber device for cooling the second adsorber device, and then through the first adsorber device. Finally, purified process gas is received at the downstream process device from the first adsorber device.

Process and apparatus for producing helium, neon, or argon product gas using an adsorption separation unit having minimal dead end volumes. A purification unit receives a stream enriched in helium, neon, or argon, and a stream is recycled from the purification unit back to the adsorption separation unit in a controlled manner to maintain the concentration of the helium, neon, or argon in the feed to the separation unit within a targeted range.

Helium-containing natural gas is processed with three gas separation stages to produce a natural gas product and a Helium-containing gas that may be injected into the reservoir from which the Helium-containing natural gas is obtained. A permeate from the first gas separation membrane stage is compressed and fed to the second gas membrane stage. The permeate from the second gas separation membrane stage is recovered as the Helium-containing gas that may be injected into the reservoir. The non-permeate from the second gas separation membrane stage is fed to the third gas separation membrane stage. The non-permeate from the first gas separation stage is a natural gas product. A permeate from the third gas separation membrane stage is combined with a non-permeate from the first gas separation membrane stage before it is compressed and fed to the second gas separation membrane stage. A non-permeate from the third gas separation membrane stage is fed to the first gas separation membrane stage along with the Helium-containing natural gas.

Process and apparatus for producing helium, neon, or argon product gas using an adsorption separation unit having minimal dead end volumes. A second separation unit receives a stream enriched in helium, neon, or argon, and a stream is recycled from the second separation unit back to the adsorption separation unit in a controlled manner to maintain the concentration of the helium, neon, or argon in the feed to the separation unit within a targeted range.

A multi-stage membrane system is provided to separate helium from a gas stream such as a natural gas stream. There are at least two permeate streams from a first membrane module. One of the permeate streams is compressed and sent to a second membrane module while one of the permeate streams bypasses the compressor. There are control means provided to determine the flow for these two permeate streams based on factors including the compressor capacity, the concentration of the target component in the combined permeate streams and the capacity of the second membrane module.

The present invention relates to a process for obtaining pure helium using a first membrane separation stage a second membrane separation stage and a third membrane separation stage. The first membrane separation stage is supplied with a first helium-containing feed mixture, the second membrane separation stage with a second helium-containing feed mixture and the third membrane separation stage with a third helium-containing feed mixture a first permeate and a first retentate are formed in the first membrane separation stage, a second permeate and a second retentate in the second membrane separation stage and a third permeate and a third retentate in the third membrane separation stage. The first feed mixture is formed using at least part of a helium-containing starting mixture. The second feed mixture is formed using at least part of the first permeate. The third feed mixture is formed using at least part of the second permeate. The third permeate is at least partly processed by pressure swing adsorption to obtain pure helium and a residual mixture at least some of the residual mixture is used in the formation of the second or third feed mixture.