Tego Magnan powder temperature

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

Table 2.13 Grain size of P-MgH, Mg, and retained P-MgH in the Tego Magnan powder after milling and desorption at various temperatures...

Figure 2.33 shows the plots of DSC desorption temperatures as a function of powder particle size (BCD) of the milled Tego Magnan powder. It can be seen in... 

Fig. 2.33 DSC hydrogen desorption temperatures vs. particle size for as-received and ball-milled Tego Magnan powder, (a) Onset temperature (T ) and (b) low-temperature (LT) and high-temperature (HT) DSC peaks. Numbers beside data points indicate grain (crystallite) size of the P-MgH phase. Standard deviation bars for the particle size (BCD) are omitted for clarity [6]...

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. 1.29 Plot ln(-ln(l - a)) vs. ln(0 for dehydrogenation of MgH (Tego Magnan ) milled for 20 h and catalyzed by 5 wt% Ni (tests were done in temperature range 275-375°C using nonacti-vated powder)...

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... 

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