Oxidative Regeneration of Spent Molybdate and Tungstate Hydrotreating Catalysts

Autor: Suehiko Yoshitomi, Nobuyuki Matsubayashi, Akio Nishijima, Takashi Kameoka, Motoyasu Imamura, T. Sato, Hiroshi Yanase, Yuji Yoshimura, Hiromichi Shimada
Rok vydání: 1994
Předmět:
Zdroj: Energy & Fuels. 8:435-445
ISSN: 1520-5029
0887-0624
DOI: 10.1021/ef00044a023
Popis: Temperature-programmed oxidation of NiMo, CoMo and NiW hydrotreating catalysts from hydrotreatment of vacuum gas oil and coal-derived oils was carried out in thermogravimetric and fixed-bed reactors. Attempts were made to elucidate the mechanism of oxidative removal of carbon and sulfur from spent catalysts, and to investigate the structural changes of active metals and some solid-phase interactions between active metals and deposited metals during regeneration in order to correlate these resulting properties with the catalytic activities of regenerated catalysts. Changes in chemical states and structure of supported metals were analyzed by EXAFS and XPS. These structural changes were also analyzed by using the thermodynamical phase diagrams. This talk will discuss the differences in the oxidative regeneration severity between Mo and W spent catalysts, structural changes of supported metals during oxidation and following sulfidation, and effectiveness of the thermodynamics to predict a priori the regeneration and following sulfidation behavior.
Databáze: OpenAIRE