Fuel Reforming and CO Removal for Transportable Hydrogen Production Systems

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Fuel Cells are highly efficiency devices, which use hydrogen as fuel, since the cells can directly convert chemical energy to electronic energy. In particular, polymer electrolyte fuel cells are compact and transportable ; therefore, they can beused in cars and houses. In transportable system, hydrogen must be produced on site. In this study, hydrogen productions form methanol and hydrocarbons were investigated.For hydrogen synthesis from methanol, supported Cu catalyst was used. For low loading catalyst, catalyst activity strictly depended on the support. The Cu catalyst supported on ZnAl_2O_4 with high surface area showed high activity. They had two kinds of active sites. One was an XRD-detectable species which showed high TOF and, the other was an XRD undetectable species which showed low TOF.Next partial oxidation of methane was conducted on Ni catalysts supported on hexaaluninate mixed oxide. Ni species was supported by the reduction of the mixed oxide at 800℃. It showed high activity and high stability even at high temperature range.CO removals from reformed methanol and hydrocarbon gasses were conducted on Cu-Al_2O_3-ZnO catalyst in the presence of small amount of oxygen. Oxygen promoted the CO removal, and enhanced CO removal in particular at low temperature of 150℃.Generation experiment was conducted on solid oxide fuel cell, inside of which methane was reformed with steam. CaO, SrO, and CeO_2 addition to Ni-YSZ cermet reduced the carbon formation rate. Deactivation for steam reforming was suppressed by the CaO addition. Performance of Ca-containing Ni-YSZ for Electrode catalyst was slightly lower than parent Ni-YSZ and showed stable activity.