重油加氢脱氮催化剂的研制 Ⅰ.载体氧化铝的pH摆动法制备

STUDY AND PREPARATION OF HDN CATALYSTS FOR HEAVY OIL I. Preparation of Support Alumina by pH Swing Method

以铝钒土酸溶出的硫酸铝经脱铁后的溶液为铝源，与碱或碱金属盐交替加料中和沉淀（即ｐＨ摆动法）制备的氢氧化铝，具有典型的拟薄水铝石结构，可直接成型制成催化剂载体γ－Ａｌ２Ｏ３。该法原料价格低廉，制备方法简便。试验考察了原料匹配、溶液浓度、反应温度、摆动次数等条件对产品孔结构参数的影响，并对产品的晶型、形貌、表面酸性质等进行了测试。该法制备的氧化铝适宜作为加氢精制催化剂的载体，且特别适用于制备加工高含氮重油的加氢脱氮催化剂。

A pH swing method was used to prepare support alumina. In the method, aluminum sulfate solution prepared by removing iron from acid leaching liquor from bauxite and an aqueous solution of alkalis or alkali salts were added alternatively during the precipitation process for producing aluminum hydroxide with a typical crystalline phase of pseudo boehmite. The effects of preparing conditions, such as raw material, concentration of solution, precipitation temperature and frequency of pH swing, on pore structure, crystal form and surface acidity of alumina were investigated. These aluminas are suitable to be used as supports of hydrotreating catalysts, especially hydrodenitrogenation catalysts of heavy oils with high nitrogen content.