Evaluation of thermal profile in catalytic reactor by exothermic hydrocarbon feed into detritiation system

Absract Air detritiation system of a fusion facility consists of catalyst reactors for tritium oxidation and a system to remove tritiated vapor from air. In the event of fire in the facility, the impact of gaseous impurities produced by polymeric materials on catalytic oxidation of tritium is one of the evaluation items. The point is the impact of reaction heat needs to be detected since gaseous impurities such as hydrocarbons are likely to combust in the catalyst reactors as well as heat generation by the combustion reaction is large. The distributions of temperature and concentration in a catalytic reactor are numerically evaluated using the thermophysical and chemical properties. The numerical analysis showed that the temperature in a catalytic reactor rose to 1173 K by the combustion of ethylene and hydrogen when air containing 1% concentration of hydrogen and 1% concentration of ethylene was fed into the reactor heated initially at 473 K. Since the increase in temperature is large, further technical consideration will emerge for designing such as the selection of material for a reactor, the increase in tritium permeation, and the impact of excessively heated air on equipment located at the downstream. The heat removal mechanism needs to be designed for catalytic reactors.