几种加氢预处理催化剂的失活原因探讨

Investigation on the Causes of Hydrotreating Catalyst Deactivation

通过小型加氢装置对催化剂进行活性评价 ,结果表明 ,失活催化剂经再生后加氢脱氮活性明显降低 ,其反应温度比新鲜催化剂反应温度高 7～ 8℃左右。通过使用XRD、XPS、TPR、ICP、IR等技术 ,测试和表征几种工业大量应用的加氢预处理催化剂 ,从不同角度研究再生前、后催化剂的各种性能的变化 ,研究、探讨催化剂失活的原因。研究表明 ,加氢预处理催化剂经工业使用后 ,导致催化剂失活的原因有 :在运转中碳的沉积使其暂时性失活、重金属沉积堵塞孔口、降低酸度、使催化剂部分活性位永久性失活 ,而金属聚集、载体烧结使催化剂加氢活性降低 。

The catalyst activity has been estimated through a small hydrogeneration unit. The results indicate that the hydrodenitrogen activity of regenerated catalyst decreased obviously compared with fresh catalyst. The reaction temperature by using regenerated catalyst is 7 - 8 °C higher than by using fresh catalyst. The physicochemical characteristics and their variation before and after regeneration of hydrogeneration catalysts largely used in commercial units were studied through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), inductive coupled plasma (ICP), and infrared spectroscopy (IR) in order to obtain the causes of catalyst deactivation. The results show that the deactivation causes of hydrogeneration catalysts used in commercial units fall into three major categories: temporal deactivation caused by pore blocking via coke deposition in the catalyst pores; permanent deactivation caused by pore blocking via heavy metal deposition at the catalyst pore mouths that decreases acidity and deactivates some active sites permanently; permanent deactivation caused by smaller metal aggregation and supports sintering.