(1) Methanation rate

Tests on all three Ni-Al203 base catalysts proved both reaction rate constants k^o and k^o2 to be significantly influenced by the reaction temperature: For this reason, the reaction constants were equated to the inverse value of reaction temperature, recorded in Arrhenius plots. Representative reaction rate equations thus empirically derived were as given below.

- For CO methanation r co= 7. 436 x 10l 3 • exp(-l. 375 x 10VR T ) • p co/(H12. 97 • p co)!

A comparison is given in Fig. 2 between the reaction rate derived by the above equation and corresponding measured data.

- For CO2 methanation r coa= 1- 063x 10'1 • exp(-1.094xl05/RT) • p co2/(l+66. 86 • p co2) where the symbols are the same as for rco, with all references to CO and co replaced respectively by CO2 and CO2.

Calculated and measured values are compared in Fig. 3. (2) Methanation performance of catalyst

The CO concentration at reactor exit varied with reaction temperature and SV as shown in Fig. 4. Table 1 presents the gas compositions analyzed at reactor entrance and exit, in terms of dry gas content, for the run using S/C = 1.55 methanol/water mixture.


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