Helium recovery from higher helium content streams

A method for the separation of helium from an input gas stream containing helium and other gases by selectively adsorbing said other gases in a first stage of pressure swing adsorption, said first stage of pressure swing adsorption consisting of at least four interconnected adsorbent beds, each adsorbent bed undergoing five phases for each complete cycle of pressure swing adsorption, said five phases comprising in sequence an adsorption phase, a depressurization phase, an evacuation phase, a purge phase and a helium pressurization phase, feeding said input gas to a first adsorbent bed of said first stage and collecting three portions of a first stage helium product gas therefrom, concurrently depressurizing a fourth adsorbent bed of said first stage which has completed the production of said first stage helium product gas and which contains substantial amounts of said other gases, recovering an effluent first stage recycle gas from said fourth adsorbent bed of said first stage and pressurizing said first stage recycle gas to about the pressure of said input gas to said first stage and flowing said first stage recycle gas to the input gas to said first adsorbent bed of said first stage, concurrently reducing the pressure in a third adsorbent bed of said first stage to less than about ambient pressure and removing at least a portion of said other gases therefrom, concurrently flowing a first portion of first stage helium product gas from said first adsorbent bed of said first stage to said third adsorbent bed of said first stage which has completed said evacuation phase as a purge gas and further removing said other gases therefrom, concurrently flowing a second portion of said first stage helium product gas to a second adsorbent bed of said first stage to increase the pressure within such adsorbent bed, and flowing said other gases from said third adsorbent bed of said first stage as a first stage secondary product gas to a first adsorbent bed in a second stage of pressure swing adsorption, said second stage of pressure swing adsorption comprising an adsorption phase, a recycle phase, a depressurization phase, an evacuation phase, a helium pressurization phase and a recycle feed pressurization phase, feeding said first stage secondary product gas to the input end of a first adsorbent bed of said second stage entering on said adsorption phase as a feed gas and selectively adsorbing other gases therefrom, collecting a second stage helium product gas flowing from said first adsorbent bed of said second stage and flowing a portion thereof to a second adsorbent bed of said second stage that has completed said evacuation phase and that has entered said helium pressurization phase, concurrently depressurizing a fourth adsorbent bed of said second stage and collecting an effluent second stage recycle gas, pressurizing said second stage recycle gas to about the pressure of said second stage feed gas and flowing said pressurized second stage recycle gas to said first adsorbent bed of said second stage upon the completion of said adsorption phase and the initiation of said recycle phase, flowing the effluent from said first adsorbent bed of said second stage during said recycle phase to a second adsorbent bed of said second stage upon the completion of said helium pressurization phase and that is to enter said adsorption phase to pressurize said second adsorbent bed of said second stage to about second stage feed gas pressure, concurrently evacuating a third adsorbent bed of said second stage that has completed said depressurization phase to remove said other gases therefrom, flowing the remaining portion of said second stage helium product gas to said first stage of pressure swing adsorption along with said input gas.