A process for the separation of the components of a gas mixture to be treated comprising methane, nitrogen and at least one hydrocarbon having at least two carbon atoms, or a mixture of these hydrocarbons, including introducing the gas mixture to be treated into a first distillation column, thereby producing, in the column bottom, a first liquid stream enriched in hydrocarbon having at least two carbon atoms and, at the column top, a first gas stream enriched in methane; and introducing the first liquid stream enriched in hydrocarbon having at least two carbon atoms resulting from stage a) into a second distillation column, thereby producing, at the top of this column, a second gas stream rich in methane and, in the bottom of this column, a second liquid stream comprising at least 85 mol % of the hydrocarbons having at least two carbon atoms initially present in the mixture to be treated.

Systems and methods are provided for recovering helium from a feed comprising helium, carbon dioxide, and at least one of nitrogen and methane. The feed is separated in a first separator to form helium-enriched stream and a CO.sub.2-enriched stream. The helium-enriched stream is separated in a pressure swing adsorption unit to form a helium-rich product stream and a helium-lean stream. At least a portion of the helium-lean stream is recycled to the first separator with the feed. In some embodiments, a membrane separation unit is used to enhance helium recovery.

A method for producing a helium gas stream from a gas source containing at least helium, methane, and nitrogen is provided. The method includes introducing the gas into a double column nitrogen rejection unit.

The present provides a helium gas separation and recovery process involving cryogenic fractionation process, which comprises cooling a dehydrated high-pressure gas stream while maintain velocity and pressure of the stream; reducing pressure of the dehydrated high-pressure gas stream via a Joule-Thompson's process to obtain a partially liquefied gas stream; and iii) subjecting the partially liquefied gas stream to at least one gas-liquid separation process to obtain at least one liquid stream and a gaseous stream comprising helium, and a residual amount of the gaseous components; recycling the liquid stream obtained in step iii) for use as cooling refrigerant to cool the dehydrated high-pressure gas stream; and purifying the unrefined helium gas stream using pressure swing adsorption (PSA) and/or membrane separation process to obtain a helium product stream having a purity of 98.0 mole % or more.

A system and method for removing nitrogen and producing a high pressure methane product stream from natural gas feed streams having wide variations in nitrogen and methane content are disclosed. Optional add-on systems may be incorporated into the nitrogen and methane separation to produce an NGL sales stream to reduce excess hydrocarbons in the nitrogen vent stream, or to recover helium. The system and method of the invention are particularly suitable for use with feed streams in excess of 50 MMSCFD and up to 300 MMSCFD and containing up to 100 ppm carbon dioxide. Typical power requirements for compressing the methane product stream to produce a suitably high pressure stream for sale are reduced according to the systems and methods of the invention.

A method for recovering a helium product fraction (6) from a nitrogen- and helium-containing feed fraction (3) is described, wherein the nitrogen- and helium-containing feed fraction (3) is partially condensed (E1), separated into a first helium-enriched fraction (5) and a first nitrogen-enriched fraction (8) and the former is cleaned again in an adsorptive manner.

According to the invention, the separation is carried out in a separation column (T), which is supplied with the first nitrogen-enriched fraction (8) as return flow and with a sub-flow of the second nitrogen-enriched fraction as stripping gas (12), wherein the stripping gas quantity (12) is set such that a third nitrogen-enriched fraction (20), which contains at least 30% of the nitrogen contained in the first nitrogen-enriched fraction (8), can be recovered in the separation column (T).

A feed gas including neon, nitrogen, and helium is cooled in a heat exchange system to a first temperature to produce a two-phase mixture that is introduced into a first phase separator and separated into a nitrogen-rich liquid and a first gaseous crude neon stream. The pressure is reduced in at least a portion of the nitrogen-rich liquid, which is vaporized in the heat exchange system to generate a portion of the refrigeration therein. The first gaseous crude neon stream is introduced into a first adsorber that removes impurities such as nitrogen. The gaseous crude neon stream is further cooled to a second temperature. A portion of the cooling duty may come from the heat exchange system and another portion may come from a cryocooler to produce a two-phase stream. The two-phase stream is separated in a second phase separator into a crude helium vapor stream and a crude neon liquid stream with the latter being introduced into a distillation column to produce a vent stream containing a helium impurity and a pure liquid neon product. The pure liquid neon product is vaporized in the heat exchange system to generate refrigeration and produce the pure gaseous neon product.

Disclosed is a segregating gas arrangement that generally comprises a gas segregation chamber, at least one cooling plate in the gas segregation chamber, and a carbon adsorber in an adsorption gas capturing chamber. The gas segregation chamber has a rim that when resting atop regolith defines a first interior environment. The cooling plates are in the gas segregation chamber, wherein the cooling plates are maintained at a first temperature above 5 K, which is a condensation temperature that higher temperature condensing gases will condense. The adsorption gas capturing chamber defines a second interior environment that is in communication with the first interior environment. The carbon adsorber is in the second interior environment and is maintained at a second temperature below 3 K. The carbon adsorber is configured to capture the low temperature condensing gas.

A system and method for removing nitrogen and producing a high pressure methane product stream from natural gas feed streams having wide variations in nitrogen and methane content are disclosed. Optional add-on systems may be incorporated into the nitrogen and methane separation to produce an NGL sales stream to reduce excess hydrocarbons in the nitrogen vent stream, or to recover helium. The system and method of the invention are particularly suitable for use with feed streams in excess of 50 MMSCFD and up to 300 MMSCFD and containing up to 100 ppm carbon dioxide. Typical power requirements for compressing the methane product stream to produce a suitably high pressure stream for sale are reduced according to the systems and methods of the invention.

A system for purifying helium gas, a method, and an application. The system includes a first gas-liquid separation device, a primary helium extraction tower, a second gas-liquid separation device, a secondary helium extraction tower, and a nitrogen removal tower, which are in sequential communication. The first gas-liquid separation device performs first treatment to convert helium-containing natural gas into a first gas and first liquid phases; the primary helium extraction tower performs first distillation on the first gas and first liquid phases to obtain a second gas and second liquid phases; the second gas-liquid separation device performs second treatment to convert the second gas phase to a third gas and third liquid phase; the secondary helium extraction tower performs second distillation on the third gas and third liquid phases to obtain crude helium and a fourth liquid phase form which nitrogen is removed by the nitrogen removal tower.