Adsorption separation of hydrogen isotopes with metallic palladium

In order to separate hydrogen isotopes by adsorption, molecular sieve or active carbon has been considered as the adsorbent, but it has been known that the desorption seems to be difficult. Palladium has been well known as a metal adsorbing hydrogen, but the difference of adsorbing capability according to the isotopes in the wide ranges of temperature and pressure has not been clarified. Therefore, the test of adsorbing hydrogen and deuterium with palladium was carried out in the ranges from 27 to 182 deg C and from 1 to 3.5 atm. As the result, the sufficient isotopic effect was confirmed, and the separation factor was measured. For separating isotopes by adsorption, it is necessary to utilize the difference of adsorbing capability at two points by swinging temperature or pressure, but pressure swinging is economically advantageous since it does not require large heat energy, and the operational time is short. Therefore, the possibility of concentration was calculated with a model on the duo-bed, a kind of pressure swinging. The experimental apparatus, experimental method and the results are reported. The separation factor was measured with hydrogen containing 10% deuterium, and the feasibility of adsorption separation was presumed. The numerical analysis of the duo-bed with a mass balance model is reported. (Kako, I.)