Osamu Nakagoe

Effect of Al loading on CaO catalysts for biodiesel production

Al loaded CaO catalysts for biodiesel synthesis were prepared with alkali co-precipitation method and investigated. The catalytic activities were examined with transesterification of triolein to oleic methyl ester (OME) as model reaction of biodiesel formation. The catalytic activity of these catalysts strongly depends on the amount of Al loading and formation of composite oxide phase on catalyst surface. The structure and nature of active sites on the catalyst surface were measured with XRD and temperature programmed desorption of CO2 and methanol. The TPD results revealed that the initial reaction activity strongly depended on the formation and stability of methoxide intermediate on the catalyst surface.

Mechanism of Soot Oxidation Over CeO2–ZrO2 Under O2 Flow

Soot oxidation over CeO2–ZrO2 (CZ) has been studied herein. The soot-CZ mixtures were observed under different contact conditions using transmission electron microscopy (TEM) and evaluated using thermogravimetric-differential thermal analysis (TG-DTA). These results indicate that the soot ignition temperature depends on the soot/CZ contact degree, and the soot oxidation rate depends on the soot/CZ contact area. The TEM observation of soot-CZ mixture quenched at T50 (50% soot conversion) indicates that soot oxidation occurs only at the soot/CZ interface. Furthermore, the soot oxidation under 18O2 flow and under He flow suggests that CZ lattice oxygen is a more active oxygen species than the adsorbed oxygen on the CZ. The CZ lattice oxygen mainly oxidizes soot; however, the adsorbed oxygen on the CZ surface does not oxidize soot at lower temperatures. Thus, the adsorbed oxygen oxidizes the reaction intermediates such as adsorbed CO on the CZ surface, which shows that CZ lattice is more active than the adsor...

Hydrogen production from steam reforming of woody biomass with cobalt catalyst

Catalytic steam reforming of woody biomass was carried out with metal oxide supported Co catalysts. These catalysts were prepared by impregnation of Co²⁺ into SiO₂, Y₂O₃ and CeO₂ powder and sol-gel method for Co/MgO. Their catalytic activities were examined as hydrogen formation from steam reforming of woody biomass with as functions of reaction temperature. As the results, the highest amount of H₂ formation shows Co/MgO at 973K while Co/SiO₂ has maximum activity at 873K. This is because of activation of MgO basic site due to CO₂ desorption from the active site. We suggest that the basicity of metal oxide supports affect the rate of steam reforming of tar rather than that of thermal decomposition of anhydrous cellulose.