Purification of gas mixtures is a major issue for tritium facilities. With purification levels often below ppm, processes that must optimize the purified gas recovery, while maintaining its efficiency across various type of impurities. In this context, we present a tritium gas purification process based on the cryocondensation of gas impurities on a cooled surface kept at cryogenic temperature. The purification efficiency was tested with a non-nuclear H₂/He mixtures, containing various type of impurities, and using gas chromatography to quantify the impurity concentration. The system performance is characterized through parametric studies of various physical parameters such as temperature, pressure, flowrate and initial impurity concentration. Several regimes are identified and compared with theoretical predictions. The study reveal that the purity might be ultimately limited by the nucleation of ice particles within the supercooled gas, later escaping the purification system. Several improvements are proposed to increase the purification efficiency.

Keywords
Cryocondensation|Purification|Chromatography|Nucleation|Hydrogen