The influence of catalyst layer thickness, δc, on the reactor behavior, for given
operating conditions, was simulated for three values of catalyst thickness, i.e. 200,
100, and 50 μm and for two different operating conditions representing relatively
extreme cases. In both cases the molar flow rates of the reactants in the reforming
channel was that of the reference one. However, one case differs from the
reference one because, for the same methane molar flow rate, the inlet methane
concentration in the combustion channel was below the LFL (lower flammability
limit) in the homogeneous phase (λ= 4.2), while the other case differs from the
reference one because the reactants inlet temperature was 900 K. It is worth
noting that, for a given molar flow rate, decreasing δc from 200 μm to 100 and 50
μm corresponds to increasing GHSV of factors 2 and 4, respectively. As above
the comparison is made with respect to the main indicators defined in section 3.7
and reported in Table 5. Results of the simulations show that in the case of runs
with λ = 4.2, changes in the catalyst thickness influence considerably both thermal
behavior and outlet conversions.