Modified Polymetallic Zeolite-Based Catalysts for Hydroprocessing Diesel Oil Fraction and Tetradecane

Abstract

According to international standards, motor fuels require limits on the content of sulfur, benzene, aromatic and olefinic hydrocarbons. To achieve this goal, it is necessary to create new, active and selective catalysts and improve technologies for deep hydrotreating and hydroprocessing. Tetradecane and diesel oil fraction hydroprocessing on modified zeolite-containing Ni(Co)-Mo(W)/Al2O3-ZSM-5 catalysts were studied under varying process conditions. The novelty of the work lies in the synthesis of new catalysts based on ZSM-5 type zeolite, modified with metals Ni(Co)-Mo(W) and active additives of rare earth metals and phosphorus. After hydrotreating the diesel oil fraction on the catalyst KT-3, the pour point decreases from -27 to -57°C, the sulfur level decreases from 0.141 to 0.059%, and the yield of the liquid phase is 92.2%. The lowest content of residual sulfur (0.005%) is observed on the KT-4 catalyst at 400°C. Electron microscopic examinations have demonstrated that the modified zeolite-containing catalysts are distributed in a highly dispersed manner, and the metal components in the active phase are primarily in the oxidized state, generating associate clusters on the surface, the dispersion, structure and state of which is influenced by the catalyst components' characteristics. The developed modified zeolite-containing catalysts have multifunctional properties and simultaneously carry out the reactions of hydrocracking, hydroisomerization, hydrodesulfurization and dehydrogenation.

Keywords

• catalyst
• diesel fraction
• hydroprocessing
• motor fuel
• tetradecane