Thesis - Oztek_Muzaffer_T_200508_MA

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V∆P m . . H ∆n AWt AWt % H = =− =− RT m s m s m s where m H = mass of hydrogen m s ∆n AWt V ∆P R T = mass of sample = change in number of moles of hydrogen = atomic weight of hydrogen atom = volume of sample cell = change in pressure = gas constant = temperature 3.1.1. Mg 2 Ni The Mg 2 Ni alloy was ball milled and a sample weighing approximately 110 mg was loaded in the DSC and heated up to 250 ºC under 3.7 atm of H 2 . The thermogram and the percent hydrogen and pressure curves for the initial hydriding step are given in Figures 9 and 10, respectively. In the thermogram, two exothermic events were observed, of which only the first one is accompanied by a pressure drop. The first peak indicated uptake of hydrogen by the alloy at an onset temperature of 148 ºC. The amount of hydrogen absorbed was slightly less than 3%. The smaller peak observed during cool down was due to some phase change that did not involve absorption or release of gas. 36
DSC 111 heat flow/mW Exo 300 Figure: Experiment:Tonguc Mg2Ni 20040520_1 Crucible:Steel Atmosphere:H2 20/05/2004 Procedure: hydriding (Zone 1) Mass (mg): 109.5 Sample temperature/°C 250 225 250 200 200 150 Peak :169.4908 °C Onset Point :148.8891 °C Enthalpy /J/g : -1045.2410 (Exothermic effect) 175 150 125 100 100 50 75 0 50 25 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Time/s Figure 9: Thermogram for initial hydriding of Mg 2 Ni. 37
Page 1 and 2: RECOVERY OF HYDROGEN AND HELIUM FRO
Page 3 and 4: ABSTRACT Waste streams of hydrogen
Page 5 and 6: I dedicate this work to my family m
Page 7 and 8: I also would like to cheer for my f
Page 9 and 10: 2.2.2.1. Hydriding and Dehydriding
Page 11 and 12: LIST OF FIGURES Figure 1. Pressure-
Page 13 and 14: Figure 34. Pressure profiles under
Page 15 and 16: 1. INTRODUCTION The focus of this s
Page 17 and 18: ecause of the difference in partial
Page 19 and 20: hydrides by dissolving large amount
Page 21 and 22: hydrogen storage alloy has a specif
Page 23 and 24: • Insensitivity to poisoning by i
Page 25 and 26: hydrogen capacity was not reproduci
Page 27 and 28: showed the lowest plateau pressure
Page 29 and 30: grain boundaries increases the tota
Page 31 and 32: These parameters are generally inte
Page 33 and 34: Figure 4. CaCu5-type P6/mmm structu
Page 35 and 36: In this study, the addition of Al t
Page 37 and 38: 2. EXPERIMENTAL 2.1.Chemicals and R
Page 39 and 40: Figure 5. The high energy Spex 8000
Page 41 and 42: 2.2.1.1. Hydriding and Dehydriding
Page 43 and 44: approximately 5 atm, and heating th
Page 45 and 46: determined by the start and end of
Page 47 and 48: 450 400 coating thickness (Å) 350
Page 49: 3. RESULTS AND DISCUSSIONS 3.1. Hyd
Page 53 and 54: The thermogram associated with the
Page 55 and 56: total time was broken into three 30
Page 57 and 58: The VTiNi sample was subjected to d
Page 59 and 60: solid solution of hydrogen rather t
Page 61 and 62: DSC 111 Heat Flow/mW 180 Exo Figure
Page 63 and 64: 100 rpm setting, the milling vial w
Page 65 and 66: BPR, 400 rpm, 5 minutes) did not re
Page 67 and 68: Table 1: Effects of various milling
Page 69 and 70: Due to the fast kinetics observed a
Page 71 and 72: The mole % Al after milling was les
Page 73 and 74: Figure 24: Percent hydrogen capacit
Page 75 and 76: the start of the heating period, wh
Page 77 and 78: However, it was noted that the part
Page 79 and 80: percent hydrogen was decreased. The
Page 81 and 82: 3.2.2.4. AuPd and Pt Coating on LaN
Page 83 and 84: 1.0 0.8 (a) (b) Wt. % H absorbed 0.
Page 85 and 86: After dehydriding by the sample, th
Page 87 and 88: 19 18 P (atm) 17 16 15 14 0.74 %Al
Page 89 and 90: GC output, arbitrary units 0 5 10 1
Page 91 and 92: sample was LaNi 5 . This may indica
Page 93 and 94: 30 min. 15 min. Intensity (arb. uni
Page 95 and 96: After milling the percentages of Al
Page 97 and 98: 4. CONCLUSIONS This study has been
Page 99 and 100: 16. Van-Vucht, J.H.N., Kuijpers, F.
Page 101 and 102:
47. Suryanarayana, C., Progress in
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Thesis - Oztek_Muzaffer_T_200508_MA

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