Multi-Component Behavior of Hydrogen Isotopes in Zeolite Packed-Beds Used for Cryogenic Pressure Swing Adsorption

Verification of hydrogen isotope separation by pressure swing adsorption process: Successive volume reduction of isotopic gas mixture using SZ-5A column

“…As has been mentioned, the adsorption process in the 1st cycle is to be longer than in the other cycles because of no tracer residual in the column. The 1st cycle experimental adsorption process, however, was shortened compared with the estimation from breakthrough curves measured in previous works [11][12][13][14][15]. Probably, the cause was in a lack of cooling time, that is, the column was not enough at 77.4 K when starting the initial operation.…”

Breakthrough curves of non-trace H2–D2 mixture replacement adsorption with SZ-13X packed column at 77.4K

“…The right-side first-term values were determined by estimating the values of D L in the bulk of H 2 or D 2 flowing through the 0 500 1000 [3,5]. These values are specialized for H 2 and D 2 in the packed column used here though D L for general gases can be calculated by an empirical equation [13].…”

“…The right-side terms of Eqs. (5) and (6) describing the dispersion can be neglected in the case of an adsorption system in which Henry's type isotherm is assumable, as follows:…”

“…In previous works [1][2][3][4][5][6][7][8], they clarified dynamic behaviors of trace one in H 2 -D 2 (99:1) mixtures in zeolite packed columns from the breakthrough curve analysis. The tracer curves can be analytical because assumptions are acceptable of ignoring the fluid outflow-rate change with breakthrough concentration variation and the change of isotope separation factor in binary component adsorption equilibrium depending on concentration.…”