重质馏分油加氢处理催化剂用Y型分子筛—钛硅氧化物复合载体研究

Mixed support of Y zeolite and titania-silica composite oxide for the heavy oil hydrotreating catalyst

采用溶胶-凝胶结合CO2超临界干燥的方法制备了钛硅复合氧化物(CTS)载体基质材料。以不同方法将Y型分子筛与CTS混合制得Y/CTS复合载体,以Ni、W为活性金属组分,采用等体积溶液浸渍法制备了加氢处理催化剂。考察了Y型分子筛与CTS的复合方式及加入量对催化剂加氢精制性能的影响,进而研究了P改性对Y/CTS结构及酸性的影响。结果表明,Y型分子筛的加入提高了CTS复合氧化物的酸性和比表面积,适当的分子筛加入量没有破坏CTS原有的结构。当Y型分子筛的加入量大于20%,Y/CTS的总酸量高于CTS,尤其是B酸量提高幅度较大,B酸强度也明显增加;Y/CTS载体中加入P以后,载体的总酸量增加,L酸的比例提高。以胜利焦化蜡油为原料,对催化剂的加氢反应性能评价结果表明,Y型分子筛的加入以及P对Y/CTS的改性,能够在一定程度上提高催化剂的加氢脱硫和加氢脱氮活性。

Titania-silica composite oxides （CTS） were prepared by the sol-gel method combined with supercritical CO2 drying, and then CTS was mixed with HY zeolite by different methods to obtain the composite supports （Y/ CTS）. The structure and acidity of the supports were further modified by P. Hydrotreating catalysts were prepared with Y/CTS as supports and Ni-W as active metal through the equal volume impregnation method. The effects of the mixed method and the content of HY zeolite in Y/CTS on the catalyst behavior were investigated. The results showed that the specific surface area and acidity of CTS can be adjusted by the addition of zeolite HY and the CTS structure retained with proper content of HY in Y/CTS; when the content of HY is more than 20%, the acidity amount of Y/CTS is higher than that of CTS, especially for the Bronsted acidity. P modification can adjust the acidity of the catalyst; the total acidity amount of the catalysts together with the fraction of Lewis acidity was increased. Shengli eoker gas oil was used as feed stock to evaluate the hydrotreating performance of the catalysts. The results indicated that the hydrodesulferization （HDS） and hydrodenitrogenation （HDN） performance can be improved by using the mixed support Y/CTS with P modification.