INVESTIGADORES
LOPEZ Eduardo
artículos
Título:
Computational Fluid Dynamics simulation of ethanol steam reforming in catalytic wall microchannels
Autor/es:
I. URIZ; G. ARZAMENDI; E. LÓPEZ; J. LLORCA; L. GANDIA
Revista:
CHEMICAL ENGINEERING JOURNAL
Editorial:
ELSEVIER SCIENCE SA
Referencias:
Año: 2011 vol. 167 p. 603 - 609
ISSN:
1385-8947
Resumen:
A three-dimensional computational fluid dynamics (CFD)
simulation study of the ethanol steam reforming (ESR) in microreactors with
square channels has been carried out. A phenomenological kinetic model
describing the ESR on a Co3O4-ZnO catalyst has been
established and implemented in the CFD codes. This model includes the ethanol
dehydrogenation to acetaldehyde, ethanol decomposition to CO and CH4,
acetaldehyde steam reforming to H2 and CO2 and water-gas
shift as the reactions describing the catalyst behavior. The very different thermal
effects and apparent activation energies of these reactions allow interpreting
the influence of the main operating parameters on the microreactors performance.
The high activation energy and low energy demand of the ethanol decomposition
limit the production of hydrogen at high temperatures and space velocities at
values of the order of 4.5 moles of H2 per mol of
ethanol fed into the reactor. Another drawback is the presence of significant
CO contents in the reformate stream. This can be partially solved by increasing
the catalyst loading which leads to a lower temperature and then an improved
selectivity to ethanol dehydrogenation and acetaldehyde reforming. The
microchannel characteristic size in the 0.10-0.70 mm range has a strong
influence on the microreactor performance that is mainly governed by the
surface area-to-volume ratio. For the smallest sizes considered in this study
(0.10 and 0.35 mm)
it has been found that the flow of the gases is nearly isothermal.