不同金属含量Ni-W催化剂的煤焦油加氢脱硫脱氮性能研究
Hydrodenitrogenation and hydrodesulfurization of coal tar on Ni-W catalysts with different metal loadings
-
摘要: 以γ-Al2O3为载体, 采用等体积浸渍法制备了五种金属原子比相同而金属负载量不同的Ni-W基催化剂。通过X射线衍射(XRD)、光电子能谱(XPS)、程序升温脱附(NH3-TPD)、氮气吸附、高分辨透射电镜(HRTEM) 等技术对催化剂进行了表征。在固定床反应器中, 以中低温煤焦油为原料, 考察了催化剂的加氢脱氮(HDN) 和加氢脱硫(HDS) 性能。结果表明, 当Ni/W原子比为0.786时, 负载金属后, 催化剂的总酸量减少, 且以中强酸为主。随着金属负载量的增加, 催化剂的硫化程度逐渐增加, HDN活性先增加后降低, 当WO3负载量为24%时达到最优值, 而HDS活性逐渐增强。Abstract: The γ-Al2O3 supported Ni-W catalysts with different metal contents for the hydroprocessing of low and middle-temperature coal tar were prepared and characterized by the X-ray diffractogram (XRD), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of NH3 (NH3-TPD), N2 adsorption and high resolution transmission electron microscopy (HRTEM). The hydrodenitrogenation (HDN) and hydrodesulfurization (HDS) performances of the catalysts were evaluated by using low and middle temperature coal tar. The results show that the sulfidation degree of the catalysts increases with increasing metal content within a certain range, while the amount of total acid that mainly consists of intermediate acid decreases. The HDN activity of the catalysts with Ni/W atomic ratio of 0.786 increases initially and reaches an optimum value at 24% WO3, and then decreases, while the HDS activity increases gradually.