Helium separation and recovery process

A process for separating and recovering helium from a nitrogen rich gas feed stream comprising up to 10 mole % of said helium, and other components comprising CO2, H2, N2, O2, Ar and water, the process comprising:

• a. providing a high-pressure gas feed stream having a pressure from 300 to 3000 psi;
• b. removing CO2 from the high-pressure gas feed stream to obtain a treated high-pressure gas stream;
• c. drying the treated high-pressure gas stream to obtain a dehydrated high-pressure gas stream;
• d. subjecting the dehydrated high-pressure gas stream to a cryogenic fractionation process comprising:
• i) cooling the dehydrated high-pressure gas stream through a heat exchanger;
• ii) reducing pressure of the dehydrated high-pressure gas stream to 100-200 psi via a Joule-Thompson's process to obtain a first partially liquefied gas stream comprising nitrogen and hydrocarbons, and gaseous components comprising helium;
• iii) subjecting the first partially liquefied gas stream to at least one gas-liquid separation process to obtain at least one liquid stream comprising condensed nitrogen and/or condensed hydrocarbons, and an unrefined helium gas stream comprising helium and a residual amount of gaseous components comprising H2, N2, and/or Ar;
• e) recycling the at least one liquid stream obtained in step iii) to the heat exchanger for use as cooling refrigerant to cool the dehydrated high-pressure gas stream via heat exchange;
• f) 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.