742. パラジウム-銀合金膜の水素透過特性に及ぼす不純物の影響

Several purification processes of plasma exhaust gas have been proposed for fuel circulation system in fusion reactor. To study the applicability of Pd-Ag alloy membrane method for the process, effects of impurities on hydrogen permeability as well as the basic permeation characteristics of Pd-25W/0Ag membrane tube were studied. Activation treatments of poisoned membrane were also examined.Experimental conditions are as follows: Driving pressure 120-1, 500kPa; Permeation temperature 653-853K; Concentration of impurities (O2, NH3, CH4, CO, CO2 and N2) 10-10, 000ppm.Permeabilities of H2 and D2 through the activated alloy tube were ruled by Sieverts' law, i.e. square root pressure dependence, and Arrhenius relations. The hydrogen permeation coefficient was not effected in such systems of impurity as H2-O2, H2-NH3, H2-O2-CH4, H2-O2-CH4-CO-CO2-N2. The square root pressure dependence was also applicable to the permeation for H2-O2 and H2-NH3 systems.The permeability decreased very much due to oil vapor from vacuum pump, however, it was easily recovered by baking of air. Deterioration of the membrane with oxygen could be regenerated by hydrogen reduction.