棒状γ-氧化铝的合成及其负载NiMo催化剂的加氢脱金属性能

SYNTHESIS OF ROD-LIKEγ-ALUMINA AND HYDRODEMETALLIZATION PROPERTY OF NiMoγ-ALUMINA CATALYST

以γ-氧化铝粉末及碳酸氢铵为原料,采用水热技术,成功制备棒状γ-氧化铝载体,并以此氧化铝为载体制备NiMo/γ-氧化铝加氢脱金属催化剂。应用X射线衍射、扫描电子显微镜、N 2吸附-脱附、H 2-程序升温脱附、拉曼光谱、原位CO吸附等技术表征氧化铝载体及加氢脱金属催化剂的结构与性质。研究发现,当γ-氧化铝粉末与碳酸氢铵质量比为1∶1.75、温度为140℃时,合成的棒状γ-氧化铝颗粒长为0.5~3μm、直径为50~100 nm,以该氧化铝为原料制备的γ-氧化铝载体比表面积为276 m^2/g、孔体积为0.79 mL/g。与常规氧化铝载体相比,以棒状γ-氧化铝为载体制备的NiMo/γ-氧化铝加氢脱金属催化剂更易于还原,催化剂中Ni-Mo-S活性位数量较多。在体积空速为1.0 h^-1、反应温度为380℃、氢油体积比为800、氢分压为15.7 MPa的条件下,金属杂质脱除率可达59.8%。

Rod-likeγ-alumina support was successfully prepared fromγ-alumina powder and ammonium bicarbonate by hydrothermal method,and NiMoγ-alumina hydrodemetallization catalyst was prepared based on the prepared rod-like/γ-alumina.The structure and properties of alumina support and the hydrodemetallization catalyst were characterized by XRD,SEM,N 2 adsorption-desorption,TPR,Raman and in-situ CO adsorption techniques.The results showed that when the mass ratio ofγ-Al 2O 3 powder to ammonium bicarbonate was 1∶1.75 and the synthesis temperature was 140℃,the synthesized rod-likeγ-alumina particle had a length of 0.5-3 microns and a diameter of 50-100 nm.Theγ-Al 2O 3 support prepared from rod-likeγ-alumina possessed the specific surface area of 276 m^ 2/ g and pore volume of 0.79 mL/ g.Compared with the conventional alumina support,the NiMo/γ-alumina hydrodemetallization catalyst from rod-likeγ-alumina was easy to be reduced,and there were many Ni-Mo-S active sites in the catalyst.Under the conditions of a LHS/V of 1.0 h^-1,a reaction temperature of 380℃,a V(H 2)/V(oil)of 800,a hydrogen pressure of 15.7 MPa,the removal rate of metal impurities reached 59.8%.