Abstract: Based on three-dimensional bulk of real four-leaf type hydrocracking catalyst, the meshfree calculation to solve the fourier partial differential equation for heat transmission was used to simulate the influence of external temperature fluctuation on the internal temperature distribution in the catalyst using industrial operating temperature and catalysts size as the boundary conditions. The analysis results show that the reactions in the catalyst do not occur under real isothermal surroundings. The maximum and average temperature increases in the cylindrical and four-leaf type catalyst as the increase of reaction heat release, space velocity, feed density, catalyst radius and length of the catalyst. Among them, the heat release and catalyst radius have much more influence. Even under ideal apparent isothermal reaction conditions, the non-isothermal area still exists in the two catalysts. When the operation conditions and catalyst size are the same, the four-leaf type catalyst has the highest internal temperature, while its average temperature and distribution are lower and better than cylindrical one.

Key words: hydrocracking catalyst, heat transmission, meshless method, numerical simulation, temperature distribution