硫化压力对NiW/Al_2O_3催化剂加氢脱硫催化性能的影响  

Effect of Sulfidation Pressure on Hydrodesulfurization Catalytic Performance of NiW/Al_2O_3 Catalyst

作　　者：倪雪华[1] 龙湘云[1] 聂红[1] 陈文斌[1] 刘清河[1] 

机构地区：[1]中国石化石油化工科学研究院,北京100083

出　　处：《石油学报（石油加工）》2016年第3期444-452,共9页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家重点基础研究发展计划"973"项目(2012CB224802)资助

摘　　要：在硫化温度623 K下,硫化压力在2.0⁸.0 MPa范围内改变时,考察了硫化压力对含和不含柠檬酸的NiW/Al₂O₃催化剂的4,6-二甲基二苯并噻吩（4,6-DMDBT）加氢脱硫催化活性的影响,并采用X射线光电子能谱（XPS）和高分辨透射电镜（HRTEM）对硫化态催化剂进行了表征。结果表明,在2.0⁶.0 MPa范围,两个催化剂的加氢脱硫催化活性均随硫化压力增加而提高,且从2.0 MPa增加至4.0 MPa时,活性增幅最大。当硫化压力超过6.0MPa后,前者活性仍继续上升,而后者活性则变化很小。相同条件下,前者的脱硫活性均高于后者。随着硫化压力的提高,催化剂中W物种硫化度上升,WS2微晶数量增多,长度变短,而WS2微晶堆叠层数则呈现先升后降趋势。催化剂脱硫活性与W物种硫化度关联度较高,并受到WS2微晶形貌变化的影响。柠檬酸的存在促进了W物种的硫化,并导致生成数量更多、长度较长、堆叠层数较高的WS2微晶。NiW/Al_2O_3 catalysts with and without citric acid were sulfided under H_2 pressures ranging from 2.0 MPa to 8.0 MPa and at 623 K.The sulfided catalysts were tested with4,6-DMDBT hydrodesulfurization(HDS)reactions and characterized by means of XPS and HRTEM techniques.In the H_2 pressure range of 2.0-6.0 MPa,the HDS activity of the both catalysts increased with the elevation of sulfidation pressures.The most significant increment in HDS activity was observed when H_2 pressure was raised from 2.0 MPa to 4.0 MPa.Under H_2 pressure above 6.0 MPa,the HDS activity of the former kept rising with the pressure increase,while that of the latter remained almost constant.Under the same conditions,the HDS activity of the catalyst with citric acid was always superior to that of the catalyst without citric acid.As the H_2 pressure was elevated,the W sulfidation degree of the both catalysts increased,more and shorter WS_2 crystallites were formed,and the stacking number of WS_2 crystallites first ascended and then descended.The HDS activity of catalyst was found to be closely correlated with its W sulfidation degree.Meanwhile,the change in WS_2 morphology could be an important factor influencing HDS activity of the catalyst.The presence of citric acid in catalyst can promote the W sulfidation to form more WS_2 crystallites with increased length and stacking number.

关 键 词：NiW/Al2O3 柠檬酸 硫化压力 加氢脱硫活性 

分 类 号：TE624.9[石油与天然气工程—油气加工工程]