FIELD: gas treatment. SUBSTANCE: step A: hydrogen flow is kept in contact at 5-50 C with one or more granular material layers containing nickel and/or nickel compounds, at least 1 wt % of nickel being present in reduced form, until easily removable impurities are almost completely removed. Step B: flow from step A essentially free of easily removable impurities but still containing harder-to-remove impurities is brought into contact with one or more layers of nonvolatile getter material at higher temperature. EFFECT: improved has treatment quality. 18 cl, 1 dwg, 1 tbl, 3 ex
