Thermodynamic analysis and performance of a 1 kW bioethanol processor for a PEMFC operation

Abstract

A thermodynamic analysis of a bioethanol steam reforming processor for CO-free hydrogen production was performed. The stages selected to perform CO purification were water gas shift and CO preferential oxidation. In order to optimize the processor efficiency, several configurations were studied. A processor efficiency of 69% for a steam/carbon ratio (S/C) of 4.8 was achieved taking advantage of the heat released during the exothermic stages. An efficiency close to 28% at the same S/C ratio for a bioethanol processor-PEMFC system, which includes a heat recovery system for off-gas from the fuel cell anode, was obtained. To produce a CO-free hydrogen rich stream, a 1 kW bioethanol processor was designed, built and operated, based on previous simulation studies. A new catalyst developed in the Institute of Catalysis and Petro-chemistry (ICP-CSIC) and tested for more than 500 h, that demonstrated excellent results at laboratory scale, was selected for the steam reforming stage. From bioethanol processor operation, a hydrogen rich stream, with CO composition as low as 3 ppmV was obtained, which is able to supply a PEMFC.