Abstract:

The influence of curing temperature on catalytic desulfurization, nitrogen and acid removal of NiW/Al₂O₃ hydrotreating catalyst during the curing tprocess was studied. The catalyst with incomplete curing was re?cured and its hydrogenation performance was studied. The structure of the vulcanized catalyst was characterized by physical adsorption (BET), X?ray diffraction (XRD) and X?ray photoelectron spectroscopy (XPS). The results showed that the sulfur content and degree of vulcanization on the catalyst increased with the increase of vulcanization temperature, and the carbon accumulation also increased, which led to the decrease of the specific surface area, pore volume and average pore size of the catalyst. After vulcanization, the active phase of the catalyst changed from low active W⁶⁺ and Ni²⁺ to high active W⁴⁺ and Ni-W-S phases. After revulcanization, the pore volume and average pore size of the catalyst decreased, while the specific surface area, sulfur and carbon contents increased. The increase in carbon deposition covered part of the active center and reduced the atomic ratio of W and Al on the catalyst surface, resulting in the aggregation of active metals in the vulcanized state and reduced the activity of the catalyst, indicating that the revulcanized catalyst was difficult to achieve complete vulcanized catalyst activity.

Key words: NiW/Al₂O₃, Vulcanization temperature, Catalyst activity, Catalyst characterization, Catalyst vulcanization degree, revulcanization

摘要：

研究了硫化温度对NiW/Al₂O₃加氢处理催化剂在硫化过程中催化脱硫、脱氮、脱酸性能的影响；对硫化不完全的催化剂进行重新硫化，并对其加氢性能进行了研究；采用物理吸附仪（BET）、X射线衍射仪（XRD）、X射线光电子能谱（XPS）等技术对硫化态催化剂进行了结构表征。结果表明，催化剂上硫、碳质量分数和硫化度随着硫化温度的升高而增加，这导致催化剂的比表面积、孔容和平均孔径均下降，硫化后催化剂的活性相由低活性的W⁶⁺、Ni²⁺相向高活性的W⁴⁺、Ni-W-S相转变；重新硫化后催化剂的孔容、平均孔径均下降，比表面积、硫质量分数、碳质量分数均增加，碳质量分数的增加导致裸露的活性中心数减少，降低催化剂表面W与Al的原子个数比，硫化态活性金属发生聚集，降低催化剂的活性，表明重新硫化催化剂的活性难以达到完全硫化态催化剂的活性。

关键词: NiW/Al₂O₃, 硫化温度, 催化剂活性, 催化剂表征, 催化剂硫化度, 重新硫化