Hydrogen breakthrough behaviors for cryogenic adsorption and HAZOP study

The exhaust gas of fusion reaction has various gaseous compounds and all of the hydrogen isotopes must be recovered and reused for the reaction. Helium is used to clean up the inside of the torus and to extract tritium from bleeding blanket. At this time, helium is the main component of the exhaust gas and contains a small amount of hydrogen isotopes. Such small quantities of hydrogen isotopes can be recovered with cryogenic adsorption method. In this work, hydrogen adsorption capacity of molecular sieve 5 A in liquid nitrogen was measured at the partial pressure of hydrogen from 1 to 12 kPa. The breakthrough behaviors of hydrogen on the adsorbent were investigated. Molecular sieve 5 A adsorbed hydrogen weakly and released the adsorbed hydrogen partially even though it did not reach to the full capacity of adsorption. It was also confirmed that the hydrogen breakthrough time was not linear proportionally to hydrogen partial pressure and input time. HAZOP study was also conducted for safe use of hydrogen isotopes.