Abstract: The high efficient operation of RHT unit is greatly influenced by feed properties, fluid distribution in reactor, catalysts and the graded loading technology. The feedstock not only influences the removal rate of hetero-atoms and CCR，but also impose an impact on the deactivation mechanism and the unit operating cycle. The inefficient fluid distribution leads to a higher radial temperature difference in reactor. The catalyst grading schemes can directly influence the activity and stability of the loaded catalysts. The mass transfer and diffusion of the residual are suffered due to the very high molecular weight and viscosity of residual oils. To solve these problems, based on the understanding of these influencing factors and practical operational experience, a series of corresponding RHT technologies were proposed by RIPP: tailored catalysts and grading technologies, crude pre-decalcification technologies, higher-efficient fluent distribution technology, switchable protection reactor technology as well as RICP technologies. According to the properties of feeds and the general process of the whole plant, several overall solutions were proposed for different RHT units. Commercial applications in three plants showed that long-term efficient operations with the overall solutions were realized.

Key words: RHT fixed bed residue hydrotreating, high efficient operation, overall solution