Hydrogen isotope separation characteristics of cryogenic distillation column

Abstract

Abstract Cryogenic distillation is a promising method for a hydrogen isotope separation system in the fuel cycle of nuclear fusion reactors. However, sufficient experimental information has not yet been obtained to enable us to achieve the cascade operation of cryogenic distillation columns. The present study aims to obtain such information. The experimental apparatus used in the present study is composed of a cryogenic distillation column, gas chromatographs and a helium refrigerator. The cryogenic distillation column can be operated in three modes; the total reflux mode, the total recycle mode and the total recycle mode with a feedback stream. In each experiment, the gas in the condenser and the gas or liquid in the reboiler are sampled and analyzed with gas chromatographs after the column pressure, the pressure drop in the packed section, and other operating conditions reach a steady state. The experimental results are arranged with the pressure drop in the packed section and the height equivalent to a theoretical plate (HETP). As a result of the total reflux experiments, it should be noted that the pre-flooding operation of the distillation column before the total reflux operation improves the separating efficiency of the distillation column and reduces the HETP value. The experimental results also show that the pressure drop increases with vapor velocity. The flooding point or the loading point is not observed with vapor velocity lower than 20 cm/s. As a result of the total recycle experiments, the HETP value is observed to decrease with reflux ratio.