加氢处理催化剂级配技术及应用进展

渣油加氢处理催化剂需要具备加氢脱金属、加氢脱硫、加氢脱氮、加氢脱残炭及部分加氢转化等功能,但目前尚未开发出集这些功能于一体的单一品种的催化剂。因此,需要根据原料性质、操作条件和对产品质量的要求,将不同功能的加氢处理催化剂级配使用。在渣油加氢反应器中,催化剂级配装填的顺序为保护剂/HDM/HDS/HDN催化剂,沿反应物流方向,催化剂尺寸、孔径在反应器内由上到下逐渐减小,而催化剂活性则逐渐增加,整个催化剂床层中催化剂的物理和化学性质要保持平稳过渡。但这种级配装填方法不适用于高含氮渣油,于是又提出了反向催化剂级配装填技术,其特点是沿物流方向催化剂活性逐渐降低,改变了HDS、HDN催化剂床层的级配,并在床层之间增设一个过渡催化剂床层,使每个催化剂床层的温升更加平稳。催化剂的级配装填最初是为了解决渣油加氢处理存在的问题,但此后其应用范围几乎扩大到各种加氢处理工艺,从而极大地改善了各种加氢处理工艺的综合技术经济指标。

Hydrotreating Catalyst Grading Technique and Application Advances

Residuum hydrotreating catalysts need to perform a series of functions such as hydrodemetallization, hydrodesulfurization, hydrodenitrification, hydrodecarbonation and partial hydroconversion.However, no catalyst that can alone perform all these functions has been developed.For this reason,catalysts with different functions must be graded in accordance with the properties of raw materials ,operating conditions and the requirements for product quality.In a residuum hydrogenation reactor,the loading sequence of catalyst grading is： protective agent/HDM/HDS/HDN catalyst,in the reaction flow direction.The dimensions and diameters of catalyst granules inside the reactor decrease and the catalyst activity increases,from the top to the bottom of the reactor. Steady transition is required for the physical and chemical properties of catalyst throughout the catalyst bed layer.However,as this grading loading method is not suitable for high-nitrogen residuum,a reverse catalyst grading loading technique has been developed.A major characteristic of this method is that catalyst activity decreases in the material flow direction.This changes the grading for HDS and HDN catalyst bed layers.In addition ,a transitional catalyst bed layer was added between bed layers and as a result,the temperature rise on each catalyst bed layer became steadier.Catalyst grading loading was originally designed to solve the problems with residuum hydrotreating.However,its application has now been expanded into almost all areas of hydrotreating.This has greatly improved the overall technical and economic indicators of various hydrotreating technologies.