humidifying a gas stream comprising the hydrogen isotope to be concentrated and an additional non-hydrogen containing gas other than the hydrogen isotope, wherein humidifying the gas stream comprises flowing the gas stream through a humidifier comprising isotopic water to form a humidified hydrogen isotope stream;

delivering the humidified hydrogen isotope stream to an anode of an electrochemical cell comprising a hydron exchange membrane comprising hydrons of the hydrogen isotope, and also comprising said anode on a first side of the hydron exchange membrane, a cathode on a second side of the hydron exchange membrane, and an electrical circuit connection between the anode and the cathode;

removing a first stream in fluid communication with the cathode, the first stream comprising concentrated hydrogen isotope; and

removing a second stream in fluid communication with the anode, comprising the additional non-hydrogen containing gas delivered to the anode depleted of the hydrogen isotope.