Influence of Framework Silica-to-Alumina Ratio on the Tritiated Water Adsorption and Desorption Characteristics of NaX and NaY Zeolites

概要

論文の詳細を見る
The fixed-bed adsorption process has been studied as one of the promising processes for the recovery of tritiated water in the field of nuclear fusion. The influence of the framework SiO2/Al2O3 ratio ranging from 2.0 to 10.0 on the tritiated water adsorption and desorption characteristics in the H2O-HTO binary systems was systematically examined using NaX and NaY zeolites. A large difference in isotherm was observed by changing the SiO2/Al2O3 ratio from 7.0 to 10.0. The framework SiO2-to-Al2O3 ratio has a slight effect on the isotope separation factor. The capacity of removable water from NaY10.0 around room temperature is approximately four times larger than that from NaA2.0 even though both zeolites have nearly the same capacity for absorbable H2O at nearly P⁄P0=1.0. The weaker interaction generates the isotope effect on desorption. The HTO dehydration ratio has a strong interrelation with the accumulative amount of purge gas. Dehydration is independent of the flow rate of the purge gas. On the design side of the water adsorption process with multi-absorber systems, the size of the water absorber such as a dryer or dehumidifier can be downscaled with NaY10.0 as the adsorbent since the consideration of the heating and cooling periods necessary for the temperature swing desorption process is not required in the NaY10.0 column.
2008-06-01