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The function of hydrodenitration is: first, to remove nitrogen from the feedstock to a level that meets the process requirements, so as to fully utilize the functionality of the hydrocracking catalyst； II. Produce products that meet specification requirements (performance characteristics such as oil stability are related to nitrogen content). The rate constants for the denitration reaction of basic nitrides vary by only one order of magnitude; quinoline exhibits the highest denitration rate, while the rate decreases as the number of aromatic rings increases. Different nitrides are affected by steric hindrance in roughly the same way. During the denitration reaction, nitrides are not adsorbed onto the catalyst surface via the terminal nitrogen atoms, but rather through the π-bonds of the aromatic rings. Before the hydrogenolysis of the C-N bonds, hydrogenation of the heterocyclic rings takes place first. Therefore, the denitration reaction should first involve the hydrogenation and saturation of the aromatic rings, followed by further ring-opening denitration. Therefore, hydrogenation denitration requires more energy than hydrogenation desulfurization. The hydrogenation activity of nitrogen-containing compounds is characterized as follows for monocyclic nitrides: pyridine > pyrrole ≈ aniline > benzene ring ； Polycyclic nitrides: polycyclic > bicyclic > monocyclic ； Heterocycles > Aromatic rings. The hydrogenation of nitrogen-containing compounds is thermodynamically characterized by low equilibrium constants for the hydrogenation reaction within the typical temperature ranges used for this process; moreover, the hydrogenation of heterocycles is an exothermic reaction, and increasing temperature is unfavorable for the hydrogenation saturation of heterocycles ； However, the hydrogenolysis and denitration reactions of heterocyclic nitrides are thermodynamically favorable in this temperature range. In summary, operating at lower reaction temperatures favors the cyclohydrogenation reaction; however, the hydrogenolysis rate is low at such temperatures, resulting in a lower overall hydrodenitration rate ； As the reaction temperature increases, on the one hand, the nitrolysis rate increases, which facilitates an increase in the denitration rate; on the other hand, the equilibrium constant of the hydrogenation reaction decreases, resulting in a lower concentration of heterocyclic hydrogenation products, and thus a decrease in the overall denitration rate. Therefore, as the temperature increases, the overall hydrogenation denitration rate reaches a maximum; before this point, the reaction is controlled by kinetics, while after that it is controlled by thermodynamics. In some cases, the thermodynamic equilibrium between heterocyclic nitrides and their hydrogenated products can limit and affect the overall hydrodenitration rate. Taking pyridine as an example, as the reaction temperature increases, the reaction rate constant for the hydrodissociation of the intermediate product obtained after the hydrogenation of pyridine increases. However, at sufficiently high temperatures, the effect of the decrease in the equilibrium concentration of this intermediate outweighs the increase in the reaction rate constant for hydrodissociation, resulting in a decrease in the overall rate of hydrogenation-denitration reaction. The temperature at which the highest conversion is achieved is related to the operating pressure; the higher the pressure, the higher the temperature required for maximum conversion. This characteristic is very similar to that of the hydrogenation of polycyclic aromatic hydrocarbons. Only under quite high pressures can the equilibrium constraint between pyridine and ** be ignored. Low temperature and high pressure are favorable for the denitration reaction of heterocyclic nitrides. The influence of the presence of other heteroatoms on hydrodenitration is due to the fact that the adsorption equilibrium constant of nitrides at active sites is much larger than that of other heteroatoms; thus, the inhibitory effect of these other heteroatoms on the hydrodenitration reaction is minimal. On the contrary, the presence of thiophene and hydrogen sulfide can even promote the hydrolysis of C-N bonds under high-temperature conditions. Taking the effect of thiophene on the denitration of pyridine as an example: at low temperatures, the hydrogenation reaction of pyridine is moderately inhibited due to competitive adsorption ； At high temperatures, the formation of hydrogen sulfide due to the HDS reaction accelerates the breakdown of C-N bonds, thereby increasing the overall rate of the HDN reaction. However, the self-blocking and mutual blocking effects between nitrides are much more significant.