The intrinsic kinetics of hydrorefining catalyst in ex-situ presulfurization was investigated using a fixed-bed penetrating method. A mathematical model was built to express the intrinsic kinetics of presulfurization ...The intrinsic kinetics of hydrorefining catalyst in ex-situ presulfurization was investigated using a fixed-bed penetrating method. A mathematical model was built to express the intrinsic kinetics of presulfurization using an unreacted shrinking core model for catalyst grains and one-dimension unhomogeneous model for beds, and then the significance of the new model was tested. Results show that the presulfurization with hydrorefining catalyst was a nonstationary process, as the reaction rate changed with time, and this first-order reaction displayed high activation energy. In this dynamic mathematical model, a correction coefficient f0 was introduced into the common power-function-formed rate equation, which indicated the effects of solid diffusion on reaction. The model with high significance was able to improve the presulfurization rate and the raw material utilization ratio, thus providing theoretical guidance for achieving high presulfurization effects.展开更多
The development and application of ex-situ presulfurization(EPRES)technology for hydrotreating catalysts has been reviewed in the present article.The studies in laboratory scale and commercial practice indicated that ...The development and application of ex-situ presulfurization(EPRES)technology for hydrotreating catalysts has been reviewed in the present article.The studies in laboratory scale and commercial practice indicated that the adoption of the EPRES catalyst in industrial application can significantly enhance the degree of presulfurization of metal oxide components,shorten the start-up period,and effectively reduce the environmental impact as well as the danger of start-up procedure in industrial hydrotreating unit.This catalyst has been proved to be versatile for different types of hydrogenation reactions.Different types of active site models are also discussed for better understanding the nature of presulfur-ized catalysts.展开更多
文摘The intrinsic kinetics of hydrorefining catalyst in ex-situ presulfurization was investigated using a fixed-bed penetrating method. A mathematical model was built to express the intrinsic kinetics of presulfurization using an unreacted shrinking core model for catalyst grains and one-dimension unhomogeneous model for beds, and then the significance of the new model was tested. Results show that the presulfurization with hydrorefining catalyst was a nonstationary process, as the reaction rate changed with time, and this first-order reaction displayed high activation energy. In this dynamic mathematical model, a correction coefficient f0 was introduced into the common power-function-formed rate equation, which indicated the effects of solid diffusion on reaction. The model with high significance was able to improve the presulfurization rate and the raw material utilization ratio, thus providing theoretical guidance for achieving high presulfurization effects.
文摘The development and application of ex-situ presulfurization(EPRES)technology for hydrotreating catalysts has been reviewed in the present article.The studies in laboratory scale and commercial practice indicated that the adoption of the EPRES catalyst in industrial application can significantly enhance the degree of presulfurization of metal oxide components,shorten the start-up period,and effectively reduce the environmental impact as well as the danger of start-up procedure in industrial hydrotreating unit.This catalyst has been proved to be versatile for different types of hydrogenation reactions.Different types of active site models are also discussed for better understanding the nature of presulfur-ized catalysts.
