渣油加氢失活催化剂的积炭规律

以正庚烷为溶剂，采用索氏抽提法对渣油加氢工业失活催化剂进行预处理，以脱除表面吸附的烃类组分；采用碳硫元素分析仪、扫描电子显微镜 能谱分析仪(SEM EDS)分别测定了失活催化剂的碳、硫含量及碳含量沿颗粒的径向分布，并采用热重 质谱联用分析仪(TG MS)和BET低温物理吸附仪研究了失活催化剂的热解行为及其孔结构的变化。结果表明，沿着反应器物流方向，失活剂的积炭量呈上升趋势，硫含量呈下降趋势；脱金属失活剂的积炭沿颗粒径向分布比较均匀，而脱硫、脱残炭失活剂颗粒的碳含量呈现边缘部位较内部含量偏高；沿物流方向，积炭氧化温度逐渐升高；积炭影响催化剂的孔结构特性，对脱金属剂的孔结构影响相对较小，而对脱硫剂、脱残炭剂的孔结构影响比较大；脱硫、脱残炭失活剂高温脱炭后，比表面积和孔容可恢复率高，尤其是脱残炭剂。

Pattern of Coke Deposition on the Spent Residue Hydrotreating Catalysts

Industrial residue hydrotreating spent catalysts were washed with hot n heptane in a Soxhlet extractor for removing hydrocarbon components adsorbed on the surface, and then were characterized by elemental analysis, SEM EDX, TG MS and low temperature physical adsorption methods to obtain their coke and sulfur contents, radial distribution of coke content, pyrolysis behavior and pore structure. The results showed that coke amount increased and sulfur amount declined in spent catalysts along the flow direction of reactor. For spent demetalization catalyst, the radial distribution of coke content was uniform relatively, while for spent desulfurization and decarbonization catalysts, it was high at the edge and low slightly in the middle of the radial direction. In addition, the temperature of coke oxidative pyrolysis increased gradually along the flow direction of reactor. Specific surface and pore volume of the catalyst lost seriously due to coke deposition. Coke deposition little affected the pore structure of demetalization catalyst, while seriously affected the pore structures of both desulfurization and decarbonization catalysts. By calcining the coked desulfurization and decarbonization catalysts, especially the coked decarbonization catalyst, the high recovery ratios of specific surface area and pore volume could be obtained.