Tego Magnan powder curves

Figure 2.1 la shows an example of PCT desorption curves for the activated commercial MgH Tego Magnan powder obtained at four different equilibrium temperatures. Figure 2.11b shows the Van t Hoff plot of In p vs. 1,000/T (where p is the pressure and T is the temperature), from which the enthalpy of decomposition of MgH of 71kJ/molH2can be obtained. This value is very close to aU the values for the enthalpy of formation of MgH obtained during absorption as reported... 

Fig. 2.11 (a) PCX desorption curves at various temperatures for the activated commercial MgH Tego Magnan powder numbers indicate the average mid-plateau pressure, (b) The Van t Hoff plot for finding the enthalpy and entropy of decomposition, which is equal to -71 kJ/mol and-134 J/ mol K, respectively. Note excellent coefficient of fit = 0.991 (p - pressure)... 

Fig. Z12 DSC curve of a commercial, as-received and nonactivated Tego Magnan powder obtained under argon flow and a heating rate 4°C/min...

Figures 2.23 and 2.24 show the desorption curves and the Arrhenius plots for the calculation of the apparent activation energy of the Tego Magnan powder milled for 20 and 100 h, respectively. In both cases desorption tests were made under 0.1 MPa...

Fig. 2.26 Hydrogen desorption curves at three different temperatures of Tego Magnan powder milled continuously for 100 h under the IMP68 mode in argon...

Figure 2.6a shows typical kinetic curves of first desorption carried out in a Sieverts-type apparatus at the initial hydrogen pressure of 0.1 MPa (atmospheric pressure of 1 bar) for the as-received, nonmilled, and nonactivated Tego Magnan powder. For each temperature, a fresh load of sample was desorbed. At each temperature in Fig. 2.6a, the desorption process is complete with 100% of MgH2 des-... 

Fig. 2.6 (a) Desorption kinetic curves at various temperatures under initial hydrogen pressure of 0.1 MPa of the as-received, nonactivated, commercial MgH powder Tego Magnan and (b) the Arrhenius plot of the desorption rate for the estimate of the apparent activation energy, fi, using kinetics data for four temperatures 350, 375, 400, and 420°C (fi -120 kJ/mol). Coefficient of fit = 0.996... 

Fig. 2.32 DSC curves for the as-received MgH2 (Tego Magnan) and ball-milled MgH2 powders (IMP2 single magnet), (a) As-received commercial MgH2. Milled for (b) 15 min, (c) 1 h, (d) 10 h, (e) 25 h, (f) 50 h, (g) 75 h, and (h) 100 h in hydrogen (heating rate 4°C/min) [6]...

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