In this study, CuO-ZnO and Fe2O3-Cr2O3 were prepared by coprecipitation and their catalytic activity in super-critical water gasification (SCWG) was evaluated at 500 and 600 degrees C. Both catalysts improved the gasification efficiency and hydrogen production from cellulose and lignin. CuO-ZnO showed a higher catalytic activity in SCWG of lignin, while Fe2O3-Cr2O3 showed a higher impact on cellulose gasification. With CuO-ZnO, the highest H-2 yield of 29.62 mol/kg was obtained in lignin gasification at 600 degrees C. The catalysts were characterized using X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H-2-TPR), and scanning electron microscopy-energy-dispersive spectrometer (SEM-EDS), showing that Fe2O3 was reduced to Fe3O4 at 500 and 600 degrees C, while Cr2O3 was only reduced at 600 degrees C. In CuO-ZnO, the component CuO was reduced to Cu at both temperatures, while ZnO was not reduced, but it varied CuO performance in SCWG. The reduction of the oxides can release active oxygen species to promote the decomposition of organics, and the formed Cu can further promote the water-gas shift reaction and carbon conversion.

The factors with effects on the grain size in Gd2O3-UO2 pellets have been investigated by metalloscope and image analyzer. We have investigated the effects on the grain size in Gd2O3-UO2 pellets due to the sintering atmosphere, blending methods, pellets position in sintering furnace, and additive U3O8, ammonium oxalate and oxides (Al, Ti, V) in Gd2O3-UO2 pellets. The results have shown that grain growth and grain size distribution homogeneity of Gd2O3-UO2 pellets were enhanced by mixing methods using ball process, additive of oxides (Al,Ti,V) and sintering of low oxidizing atmospheres. The effect of adding U3O8 and ammonium oxalate on the grain growth of pellets is not obvious.