초록 ▼

The disclosed hybrid membrane and pressure swing adsorption process can recover helium from source streams of about 0.5 to 5 percent by volume helium and concentrate the helium to a concentration of greater than about 98 percent by volume. The process comprises a membrane separation followed by two

The disclosed hybrid membrane and pressure swing adsorption process can recover helium from source streams of about 0.5 to 5 percent by volume helium and concentrate the helium to a concentration of greater than about 98 percent by volume. The process comprises a membrane separation followed by two stages of pressure swing adsorption which are used in series. The source gas will primarily contain hydrocarbons but will contain some nitrogen. The membrane unit will contain a semipermeable membrane which is permeably selective for helium and will to the extent feasible reject hydrocarbons. The permeate gas will be increased in helium content by 2 to 10 times. Part of the residue gas is used in the regeneration of the adsorbent beds in the first stage of pressure swing adsorption. Each stage of pressure swing adsorption will contain a plurality of adsorbent beds, and will be cycled through multiple phases. In the first stage the adsorbent beds will sequentially undergo the phases of adsorption, recycle, depressurization, evacuation, helium pressurization and recycle feed pressurization. The product gas from the first stage is flowed to the second stage and in the second stage sequentially will undergo the phases of adsorption, depressurization, evacuation, purge, and helium pressurization. The offgas from the evacuation and purge in the second stage is flowed to input to the first stage. The process efficiently produces a product stream with a helium content of more than 98 percent by volume.

대표청구항 ▼

A method for the separation of helium from an input gas stream containing helium and other gases comprising feeding said input gas from a source to a membrane separation unit at an elevated pressure, flowing a residue stream from said membrane separation unit, a first portion of said residue gas str

A method for the separation of helium from an input gas stream containing helium and other gases comprising feeding said input gas from a source to a membrane separation unit at an elevated pressure, flowing a residue stream from said membrane separation unit, a first portion of said residue gas stream being flowed to the source of said input gas and flowing a permeate gas stream enriched in helium from said membrane separation unit to a first stage of a first stage and a second stage pressure swing adsorption unit and after processing said permeate gas in said first stage of pressure swing adsorption flowing the non-adsorbed portion of said permeate gas from said first stage of pressure swing adsorption to said second stage of pressure swing adsorption, said first stage of pressure swing adsorption and said second stage of pressure swing adsorption each containing a plurality of interconnected adsorbent beds, the first stage of pressure swing adsorption concentrating the helium in said input gas stream to greater than about 50 percent helium by volume and in said second stage of pressure swing adsorption concentrating said input gas stream to greater than about 95 percent helium by volume, a second portion of said residue gas stream being fed to said first stage of pressure swing adsorption as a processing gas.