Present status of hydrogen isotope separation by CECE process at the NIFS

Abstract

At the National Institute for Fusion Science experimental studies on hydrogen isotope separation by a combined electrolysis catalytic exchange (CECE) process have been carried out in order to apply it to the system of water detritiation for D–D burning experiments of the large helical device (LHD). Isotope separation experiments of hydrogen and deuterium are performed with two types of packed beds filled with Kogel catalysts (4.0–6.7 mm spherical, 0.8 wt% Pt deposited) and Dixon gauze rings (6 mm outer diameter, 6 mm height). One is the layered bed where layers of Kogel catalysts and that of Dixon gauze rings are filled in the column alternately. The other is the homogeneous bed where Kogel catalysts and Dixon gauze rings are mixed and filled in the column homogeneously. The separative performance of the homogeneous bed is appreciably greater than that of the layered bed, where the quantities of the catalysts are equal for both beds. The homogeneous packed bed exhibits fine performances; pressure drop is small in the range of 40–300 Pa/m and the coefficient of vapor-liquid mass transfer becomes more than 900 kmol/m 3/h, while the superficial velocity is in the range 0.2–0.7 m/s.