Ethanol catalytic membrane reformer for direct PEM FC feeding

R. KOCH; E. LÓPEZ; N. DIVINS; M. ALLUE; A. JOSSEN; J. RIERA; J. LLORCA

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2013 vol. 38 p. 5605 - 5615

0360-3199

In this paper an ethanol reformer based on catalytic steam reforming with a catalytic honeycomb loaded with RhPd/CeO2 and palladium separation membranes with an area of 30.4 cm2 has been used to generate a pure hydrogen stream of up to 100 ml/min to feed a PEM fuel cell with an active area of 5 cm2. The fuel reformer behavior has been extensively studied under different temperature, ethanolewater flow rate and gas pressure at a fixed S/C ratio of 1.6 (molar). The hydrogen yield has been controlled by acting upon the ethanol-water fuel flow and gas pressure. A mathematical model of the ethanol reformer has been developed and an adaptive and predictive control has been implemented on a real time system to take account of its nonlinear behavior. With this control the response time of the reformer can be reduced by a factor of 7 down to 8 s. The improved dynamics of the controlled reformer match better the quickly changing hydrogen demands of fuel cells. They reached a magnitude where costly hydrogen buffers between the reformer and the fuel cell can be omitted and an electric buffer at the output of the fuel cell is sufficient.