储氢材料课件（英文）-2.ppt

3) Metal-hydrogen system 1957 German Gleuckauf and Kitt Diffusion through Pd black bed. Ⅱ. Hydride hydrogen isotope separation (1) Clean H2 out; (2) Pass He through; (3) Pass 40% D2 + 60% H2 (2.5 dm3). 2.4 Isotope effect of H.S.A. 1) Thermodynamic I.E. (1) Difference in equilibrium pressure of isotopes. Normal or positive effect: PT2 PD2 PP2 Inverse or negative effect: PP2 PD2 PT2 Ⅱ. Hydride hydrogen isotope separation (2) Mechanism of thermodynamic I.E. due to difference of potential in potential wells (势阱). Tetrahedral Octahedral ED EP, negative effect EP ED, positive effect At same T: PP2 PD2 PT2 PT2 PD2 PP2 Ⅱ. Hydride hydrogen isotope separation (3) Major elements and alloys obeying the rule of positive I.E. Pd, Ce, La, Mg, Ti, U……. TiNi, LaNi5 at room temp. at room temp., Peq TiNiD is 10× higher than TiNiH. (4) Some elements and alloys obeying the rule of negative I.E. Li, V, Nb, LaNi5 (at low temp.) Ⅱ. Hydride hydrogen isotope separation (5) Effect of temperature on I.E. is noticeable 2) Kinetic I.E. Positive and negative kinetic I.E. Ⅱ. Hydride hydrogen isotope separation speed of diffusion light elements are generally higher in diffusion speed. VP VD VT positive effect VT VD VP negative effect (1) chromatographic method (色谱); displacement chromatography. (2) pressure swing adsorption method; temp. swing adsorption method. (3) cascade (串级) pressure swing; (4) multi-stage compression and absorption. 1) Methods 2.5 Some promising metal-hydride hydrogen isotope separation methods Ⅱ. Hydride hydrogen isotope separation 2) Displacement chromatography (1) Gleuckauf and Kitt Pd black (2) Aldridge experiment on HSAs 65 different HSAs tried : V, ABx alloys (x=2,5; A= La, Ce