低丰度氚气体的浓缩与回收实验

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

为进一步降低含氚氢同位素尾气的氚丰度,实现高效的氚回收,降低氚排放源项对环境的影响。本研究开展基于热循环吸附工艺的低丰度氚气体回收实验。在填充载钯硅藻土(Pd/K)的分离柱低温时,将氢同位素气体从前端注入,随后进行热循环吸附过程,数次循环后,在分离柱前端得到富集的轻组分,后端得到浓集的重组分。结果显示,氚丰度3.2%的气体进入实验系统,经7次回流循环,分离柱前端氚丰度小于0.01%;实验共处理低丰度气体7.55 mol,获得了氚丰度小于0.05%的尾气7.42 mol,平均丰度98.68%的氚气72.31 mmol以及平均丰度29.68%的中丰度气体47.93 mmol,系统氚回收率达99.54%。实验验证热循环吸附优化工艺可以降低尾气氚丰度和直接获取高丰度氚气体产品,实现氚的有效提取。

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.