The effect of temperature and amount of Ni in catalysts In the autothermal reforming of methane is shown in Fig. 6. Methane conversion increases with increasing reaction temperature. Catalytic activity increase with increasing of amount of Ni. The thermodynamic equilibrium of methane reforming were attained only at temperature high 750°C and for catalysts containing 5 and 10 wt % of Ni.
Thus, for autothermal reforming of methane the Ni (10 wt.%) catalyst supported over Ce02-Zr02-Ca0/Al203 showed high activity and stability. We can use the Ni – Ce02- Zr02-Ca0/Al203 catalyst as the catalyst for the second layer of the two-layer reactor for methane autothermal reforming.
Fig. 6. Temperature dependence of methane conversion for autothermal reforming of methane over Ni – CeCF-
The concept of the two-layer fixed-bed reactor seems to be quite promising for the steam or autothermal reforming of ethanol to syngas. According to this concept, ethanol is first converted to the H2, CO, C02 and CH4 gas mixture over a bimetallic catalyst (for example, Cu-Pd/Ce02-Zr02) and then the mixture produced is converted to syngas over another Ni-contain catalyst by autothermal reforming. It has been shown that the use of
the two-layer fixed-bed reactor prevents coke formation and provides the syngas yield closed to equilibrium. It was found that the bimetallic catalyst being essentially more active then the catalyst containing Pd only. For autothermal reforming of methane (produced after ethanol decomposition in the first layer), the Ni (10 wt.%) catalyst supported over Ce02-Zr02-Ca0/Al203 showed high activity and stability for autothermal reforming of methane.