Methane steam reforming coupled with methane catalytic combustion by direct
heat transfer in a plate catalytic reactor was successfully modelled in 2D and 3D
geometries.
The proximity between the heat source and heat sink increases the
efficiency of heat transfer resulting in transverse temperature gradients do not
exceeding, generally, 0.7 K across the metallic wall and 20 K across the gas in the
channel. In addition, such a proximity allows heat fluxes between heat source and
heat sink of the order of 105 W/(m2 s), impossible to realize in conventional
reformers.
The decrease of transverse temperature differences and of intraphase mass
transfer resistances have the global effect to contain the reactor dimension and the
catalyst amount.
Results obtained with the 2D and 3D models under the same operating
conditions evidenced relatively small differences in the assessment of the reactor
performance.
Change of reactor performance, as consequence of countercurrent (CTC)
and concurrent (CNC) flow patterns of endothermic and exothermic reactant
streams, have been obtained showing a significant prevalence of CNC flow
pattern.
Results indicate that steam reforming of methane in a surface-bed reactor
is feasible provided that mass flow rates, channels width, catalyst loadings and
thickness are properly designed.