超臨界水中ビチュメン改質反応の速度的考察

要約のみTohoku University阿尻雅文課

Different Metal Support Interactions over NiK/Mixed Oxide Catalysts and Their Effects on Catalytic Routes in Steam Catalytic Cracking of Vacuum Residue

NiK/ceria-zirconia (CZ) and NiK/ceria-zirconia-alumina (CZ-A) catalysts were investigated in order to further understand the roles of mixed-oxide supports in the steam catalytic cracking of vacuum residue (VR). Compared to thermal cracking, higher conversions and liquid yields were achieved over the catalysts. Steam decomposition occurring over the CZ and ZrO2 phases provided an alternative hydrogen and oxygen sources for hydrogenation and oxidative cracking, respectively. The introduction of Ni into the CZ support induced the formation of Ce-x(Zr-Ni)(1-x)O2-delta solid solution and the isolation of the ZrO2 phase via a strong metal support interaction, resulting in greater oxygen vacancy in the bulk structure. In contrast, the strong interaction of CZ and Ni phases with Al2O3 induced higher dispersions of CZ and Ni phases in the NiK/CZ-A catalyst, which resulted in a greater density of oxygen vacancies on the surface and higher CeO2 reducibility. As a result, the quality of the liquid products and naphtha yields were significantly improved by hydrogenation over the nickel metallic sites and oxidative cracking through the metal support interaction

Effect of a CeyNi1-yO2-delta solid solution on the oxidative cracking of vacuum residue over NiK/CeO2

In this study, a NiK/CeO2 catalyst was employed to investigate the interaction between Ni metal and CeO2 support and its effect on the oxidative cracking of vacuum residue (VR). In the reaction results, a large amount of light oils, including naphtha, diesel and VGO, was produced through oxidative cracking over CeO2, and the quality of the liquid products was significantly improved by hydrogenation. The interaction between Ni metal and CeO2 support induced the formation of a CeyNi1-yO2-delta solid solution and increased the number of oxygen vacancies, thus enhancing the oxidative cracking of VR. Further, the addition of NiK into the supports provided Ni metallic sites for hydrogenation, producing more liquid products with a high H/C ratio. As a result, the NiK/CeO2 catalyst showed a higher diesel yield (22.87%) than that without catalyst (9.14%)