Fuel processor for hydrogen production from methanol for PEM fuel cell

Abstract

The purpose of this study is to produce H₂-rich stream from methanol by an integration of steam reforming (SRM) and preferential CO oxidation (PROX). In SRM part, a series of supported Au catalysts were compared to MegaMax 700. It was found that 5%Au/(50:50)CuO–CeO₂ expressed complete methanol conversion, being higher than the performance of MegaMax 700. It was also stable and active in whole period test for 540 min. From the statistical analysis of four factors chosen at 95% confidence interval and central composite rotatable design (CCRD) falling response surface analysis, complete methanol conversion at a low CO selectivity was achieved with an operating temperature of 306.43 °C and an steam/methanol ratio of 2. The developed model was adequate. In PROX part, the effects of catalyst type, composition in catalyst, catalyst preparation, pretreatment condition, feedstream composition, operating temperature and mode of reactor was studied and revealed that 1%(1:1)PtAu/(1:1)CeO₂–ZnO prepared by co-precipitation exhibited the highest performance and was stable for ~60 h. From statistical analysis with face-centered central composite design (FCCCD) for PROX part, the optimum statistical conditions were found to lie within an operating temperature from ~100 °C to ~115 °C and 9–12% CO₂ content, in close agreement with the experimental results. When producing hydrogen with CO content less than 50 ppm by an integrating of SRM and PROX, hydrogen was yielded around ~75% at rate of ~320 L d-1 gcat-1.