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Unformatted text preview: 0C900. Other side
products were CO2 and CH4. Traces of C2H4 and C3H6, were observed over several
catalysts (Y < 0.5%). Over the reference catalyst results were obtained very similar to
the catalyst Ni72C900. The results of the catalyst screening at 800°C are compared in Figure 33. Here again
the conversion of O2 was found to be almost complete in all experiments. The C3H8 4. Results and discussion - catalytic partial oxidation of propane 110 ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp
conversion and the yields of CO and H2 were for each catalyst generally higher than at
700°C and differences between the catalysts less pronounced. Again the catalysts with
a low to medium Ni/Mg ratio showed superior performance. As at 700°C the trend in
the yield of CO reflected the trend in the C3H8 conversion and the yield of H2 was lower
than the yield of CO and proved dependent on the catalyst. The most CO and H2 was
yielded over the catalysts Ni10C900 (90 and 73%, respectively). As in the catalytic
screening at 700°C H2O was found to be the main side product followed by CO2 and
CH4. Their yield was generally lower at 800°C than at 700°C. Also traces of C2H4 and
C3H6 were observed over the catalysts with a high Ni/Mg ratio, but again their yield was
very low (Y < 0.5%). The performance of the reference catalyst was similar to that of
Ni50C900. The catalysts exhibited higher stability with time on stream (TOS) and a lower tendency
towards coke formation at 800 than at 700°C (Fig. 34). The stability with time-onstream (TOS) exhibited no clear tendency. Of the HT derived catalysts Ni10C900
showed the best stability. The apparent improvement of several catalysts with TOS,
especially for the reference catalyst is mainly due to the fact that here the catalysts
needed a longer time to reach steady state conditions at which they were stable as
shown in Figure 35. Figure 35 also shows the good reproducibility of the catalytic tests.
Except for the reference catalyst the tendency towards coke formation was...
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