Study on Adsorption Kinetics of Gaseous Iodine by 8% Silver Loaded Mordenite
-
摘要: 为了除去乏燃料后处理过程产生的放射性碘,本研究采用8%载银量的丝光沸石作为吸附剂,采用动态吸附法研究了在气体线速度、吸附柱高度、湿度和NO2体积分数等因素下其对气态碘的吸附效果的影响。实验结果表明,气体线速度对饱和吸附容量几乎没有影响,在较低气体线速度条件下,吸附柱传质阻力会增大;吸附柱高度对传质阻力几乎没有影响,随着吸附柱高度的增加,饱和吸附容量有一定的提高;湿度不影响吸附效果;NO2对吸附效果具有促进作用;Yoon-Nelson模型能够很好地拟合碘在8%载银丝光沸石吸附柱上的吸附过程。Abstract: To remove radioactive iodine from spent fuel reprocessing, in this study, 8% silver loaded mordenite was used as the adsorbent, and the dynamic adsorption method was used to study the effects of gas linear velocity, adsorption column height, humidity and NO2 volume fraction on the adsorption effect of gaseous iodine. The experiment results show that the gas linear velocity has little effect on the saturated adsorption capacity, and the mass transfer resistance of the adsorption column increases at lower gas linear velocity; The height of the adsorption column has little effect on the mass transfer resistance. With the increase of the height of the adsorption column, the saturated adsorption capacity increases to a certain extent; Humidity does not affect the adsorption effect; NO2 can promote the adsorption effect; Yoon-Nelson model can well fit the adsorption process of iodine on 8% silver loaded mordenite adsorption column.
-
Key words:
- Silver loaded mordenite /
- Post treatment /
- Gaseous iodine /
- Kinetics
-
表 1 在不同温度、湿度、NO2体积分数下8%载银丝光沸石的吸附容量
Table 1. Adsorption Capacity of 8% Silver Loaded Mordenite under Different Temperatures, Humidity and NO2 Volume Fractions
温度/
℃相对湿
度/%NO2体积
分数/%穿透时
间/min穿透吸附量/
(mg·g−1)饱和吸附量/
(mg·g−1)30 100 0.1 200 81.6 102.5 70 100 0.1 245 100 127.1 70 50 0.1 240 96.8 128.3 70 15 0.1 255 102.8 129.6 30 100 0.3 245 100 112.8 70 100 0.3 280 114.4 133.2 表 2 不同线速度下的Yoon-Nelson模型参数
Table 2. Yoon-Nelson Model Parameters at Different Linear Velocities
线速度/(cm·s−1) k′/min−1 τ/min τexp/min R2 22 0.034 251.2 250.6 0.916 13 0.030 376.7 406.5 0.964 5.5 0.013 1032.3 990.6 0.970 τexp—实验所得的50%的穿透时间 表 3 不同吸附柱高度下的Yoon-Nelson模型参数
Table 3. Yoon-Nelson Model Parameters at Different Adsorption Column Heights
吸附柱高度/ cm k′/min−1 τ/min τexp/min R2 2.2 0.035 300.0 300.0 0.954 4.4 0.029 641.7 630.4 0.963 6.6 0.024 950.0 954.6 0.990 -
[1] 刘玉珠,刘卉. 气态放射性碘捕集方法研究进展[J]. 辐射防护通讯,1996, 16(6): 28-31. [2] 叶明吕,茅云,唐静娟,等. 动力堆核燃料后处理过程废气中碘的去除的研究−吸附放射性碘用的附银硅胶的制备和筛选[J]. 核技术,1985(2): 65-68. [3] 梁飞,李永国,张计荣,等. 核燃料后处理厂溶解废气中放射性碘吸附材料的研究与应用[J]. 中国辐射卫生,2015, 24(4): 423-426. [4] 岳龙清,罗德礼. 捕集气体中放射性碘用固体吸附材料研究进展[J]. 材料导报,2012, 26(S1): 285-289. [5] 李启东, 何燧源, 黄昌泰. 放射性废气中碘的净化和监测[M]. 北京: 中国原子能出版社, 1986. [6] 梁俊福,何千舸,刘学刚,等. 溶液堆的应用及其核燃料处理[J]. 核化学与放射化学,2009, 31(1): 3-9. [7] 董瑞林,郭亮天. 无银13X分子筛吸附后处理厂溶解废气中放射性碘的实验研究[J]. 辐射防护,1994, 14(2): 110-117. [8] 熊伟,曹骐,王海军,等. 载银丝光沸石和载银氧化铝对气态碘的吸附研究[J]. 核动力工程,2019, 40(1): 131-134.