纳米SiO_(2)对NiMo/γ-Al_(2)O_(3)加氢处理催化剂性能的影响

Effect of nano-silica on the performance of NiMo/γ-Al_(2)O_(3) hydrotreating catalysts

通过在载体制备过程中加入不同含量的纳米SiO_(2)分散液,制备了不同纳米SiO_(2)含量的NiMo/γ-Al_(2)O_(3)加氢催化剂,研究了纳米SiO_(2)的加入对催化剂加氢性能的影响;采用N_(2)吸附-脱附、NH_(3)-TPD、FTIR、H_(2)-TPR、HRTEM等方法对载体及催化剂进行了表征。实验结果表明,添加纳米SiO_(2)使催化剂的硫化度整体提高,催化剂的酸量增加;当载体中纳米SiO_(2)含量达到6%(w)时,催化剂的MoS_(2)片晶长度最短、片晶层数最多,催化剂的中强酸量和B酸量达到最大值,催化剂的加氢性能最佳;在压力4.0 MPa、温度340℃、液态空速2.0 h^(-1)、氢气与原料油体积比600∶1的条件下,该催化剂的加氢脱硫率和加氢脱氮率分别达到91%和88%。

The hydrogenation catalysts NiMo/γ-Al_(2)O_(3)with different content of nano-silica were prepared by adding nano-silica dispersion in the preparation process of the support.The effect of nanosilica on the hydrogenation performance of the catalysts was studied.The support and the catalysts were characterized by N_(2)adsorption-desorption,NH_(3)-TPD,FTIR,H_(2)-TPR and HRTEM.The results showed that the addition of nano-silica dispersion not only improved the overall vulcanization degree but also improved the acid content of the catalysts.When the content of nano-silica in the support was 6%(w),the length of MoS_(2)lamellar crystal of the catalyst was the shortest,the number of lamellar crystal layers was the largest,the amount of medium strong acid and B acid of the catalyst reached the maximum,and the hydrogenation performance of the catalyst was the best.Under the conditions of 4.0 MPa,340℃,LHSV 2.0 h^(-1)and volume ratio of hydrogen to oil 600∶1,the hydrodesulfurization rate and hydrodenitrification rate of the catalyst reached 91%and 88%respectively.