Modeling and experimental investigation on phase isotope exchange of water in a wet scrubber column for air detritiation system

Air detritiation systems are important for tritium confinement during fusion reactor operations. The wet scrubber technology is recommended for the removal of tritiated water vapour in air detritiation systems, which are operated in a wet scrubber column without the need to regenerate the adsorbent. To systematically evaluate the performance of the wet scrubbing process, a combination of experimental and modeling approaches was employed to investigate the purification of air flows containing deuterium or tritium. The effects of feed water flow rate, superficial gas velocity, operating temperature, and feed gas pressure are discussed to reveal the decontamination performance. The rigorous steady-state equilibrium stage model established in this study accurately predicted the wet scrubbing process. The molar ratio of water vapour flow to the flow of liquid water in a packed column is an important parameter for controlling the efficiency of hydrogen isotope removal from the airstream. The height equivalent to the theoretical plate is affected by the superficial gas velocity at high operating temperatures; therefore, the wet scrubbing process is more suitable for operation at or below ambient temperature. Furthermore, the very low liquid spray density in the column results in poor packing wetting, and the phase isotope exchange is insufficient at high operating temperatures. The pressurisation of the feed gas produces a large decontamination factor with higher energy consumption. The model also accurately predicted tritium removal, and the design of the air detritiation process could be aided by the model.