Simulation of a low temperature water gas shift reactor using the heterogeneous model/application to a pem fuel cell

PABLO GIUNTA, NORMA AMADEO, MIGUEL LABORDE

JOURNAL OF POWER SOURCES

Elsevier

Lugar: Amsterdam; Año: 2006 vol. 156 p. 489 - 496

0378-7753

In the last few years, a renewed interest in the water gas shift (WGS) reaction at low temperature has arisen due to its application to fuelcells.In this work, a simulation of a fixed bed reactor for this reaction, which forms part of a hydrogen production–purification train for a 10 kWPEM fuel cell using ethanol as the raw material, was carried out. A commercial Cu/Zn/Ba/Al2O3 catalyst was employed and a one-dimensionalheterogeneous model was applied for the simulation. The catalyst deactivation due to thermal factors (sintering) was taken into account in themodel. Isothermal and adiabatic regimes were analyzed as well.Results of the simulation indicate that the pellet can be considered isothermal but temperature gradients in the film cannot be disregarded. Onthe other hand, concentration gradients in the film can be ignored but CO profiles are established inside the pellet. Adiabatic operation can berecommended because of its simplicity of operation and construction. The reactor volume is strongly sensitive to the CO outlet concentrationat CO levels lower than 6000 ppm. For a 10 kW PEM fuel cell, using adequate pellet size and taking into account the catalyst deactivation, areactor volume of 0.64 l would be enough to obtain an outlet CO concentration of about 7160 ppm. This concentration value can be handledby the next purification stage, COPROX.