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equilibrium data the conversions at 600 °C are significantly lower than the
equilibrium conversion values, whereas the conversions are closer to equilibrium at
750 °C (Figs. 4 and 5). Since the conversions are not much affected by the time-onstream (TOS) up to 4 hr., the catalyst does not get significantly deactivated during
this limited time period. Furthermore, the conversions of CH 4 are larger than those
observed for CO 2 , which is consistent with high contact time data used in the present
study. At high contact time, the conversions are expected to approach equilibrium.
At low contact times, the CH 4 conversions have been reported to be lower than CO 2
conversions due to the presence of the RWGS reaction, which consumes additional
CO 2 [12].
3.2 Increasing Reactor Temperature Marginally Increases
the H 2 /CO Ratio
Attaining higher H 2 /CO ratio is desirable for further processing of products of the
DRM reaction. Although equilibrium H 2 /CO ratios decrease significantly as the
temperature of the reactor increases, we found a small increase in actual H 2 /CO
ratio from 0.64 to 0.73 as the reactor temperature was increased (Fig. 6). An increase
in H 2 /CO ratio indicates that the reactor was operating under the kinetic regime.
Fig. 5 Variation of %CO 2 conversion during 4 h time on stream for DRM (CH 4 :CO 2 :N 2 = 1:1:1)
at 1 atm. over 10%Ni/MgAl 2 O 4 at 600 and 750 °C
S. Gupta et al.
equilibrium data the conversions at 600 °C are significantly lower than the
equilibrium conversion values, whereas the conversions are closer to equilibrium at
750 °C (Figs. 4 and 5). Since the conversions are not much affected by the time-onstream (TOS) up to 4 hr., the catalyst does not get significantly deactivated during
this limited time period. Furthermore, the conversions of CH 4 are larger than those
observed for CO 2 , which is consistent with high contact time data used in the present
study. At high contact time, the conversions are expected to approach equilibrium.
At low contact times, the CH 4 conversions have been reported to be lower than CO 2
conversions due to the presence of the RWGS reaction, which consumes additional
CO 2 [12].
3.2 Increasing Reactor Temperature Marginally Increases
the H 2 /CO Ratio
Attaining higher H 2 /CO ratio is desirable for further processing of products of the
DRM reaction. Although equilibrium H 2 /CO ratios decrease significantly as the
temperature of the reactor increases, we found a small increase in actual H 2 /CO
ratio from 0.64 to 0.73 as the reactor temperature was increased (Fig. 6). An increase
in H 2 /CO ratio indicates that the reactor was operating under the kinetic regime.
Fig. 5 Variation of %CO 2 conversion during 4 h time on stream for DRM (CH 4 :CO 2 :N 2 = 1:1:1)
at 1 atm. over 10%Ni/MgAl 2 O 4 at 600 and 750 °C
S. Gupta et al.