Experimental Study on Tritium Concentration and Recovery of Hydrogen Isotope Gas with Low Tritium Abundance

In order to further reduce the tritium abundance of hydrogen isotope exhaust with low tritium content, realize the recovery of tritium efficiently, and reduce the impact of tritium emission sources on the environment, this paper carried out the research of low-abundance tritium recovery process based on thermal cycle adsorption process. When the separation column packed with palladium deposited on kieselguhr (Pd/K) is at low temperature, hydrogen isotope gas is injected from the front end, and then the column is controlled to perform a heating-cooling cycle. After several cycles, the light component argon is enriched at the inlet of the separation column, and the recombinant tritium concentration is concentrated at the outlet. The research showed that the gas with a tritium abundance of 3.2% entered the experimental system, and after 7 cycles, the tritium abundance at the inlet of the separation column is less than 0.01%. A total of 7.55 mol of low-abundance gas is processed in the experiment, and finally 7.42 mol of the exhaust gas with a tritium abundance of less than 0.05% was extracted, as well as 72.31 mmol of tritium gas with an abundance of 98.68% and 0.048 mol of a medium-abundance gas with an average abundance of 29.68%. The system tritium recovery rate reached 99.54%. Experiments have verified that the thermal cycle adsorption optimization process can further reduce the tritium abundance in the exhaust gas and directly obtain high-abundance tritium gas products, greatly increasing the effective extraction of tritium.