Zr改性Y分子筛中油型加氢裂化催化剂设计制备

Development of hydrocracking catalyst supported on Y zeolite modified with Zr

采用等体积浸渍法对Y分子筛进行了Zr修饰改性,系统考察了不同用量Zr对改性Y分子筛的结构、催化剂的理化性质和加氢裂化反应性能的影响规律。通过XRD、NH3-TPD、H2-TPR和TEM等方法对改性分子筛和催化剂进行表征分析。结果表明:Zr改性降低了Y分子筛的酸量,随着改性Zr用量的增加,这种变化趋势不断增大。同时,Zr改性有效地削弱了分子筛催化剂中金属活性组分与载体间的作用,提高了W物种在催化剂表面的分散程度。加氢裂化反应结果表明:与Y分子筛催化剂相比,Zr改性Y分子筛催化剂的减压馏分油(VGO)转化率降低,中间馏分油选择性提高约20%,随着改性Zr用量的增加,VGO的转化率不断降低,中间馏分油选择性略有增加。

Y zeolite was modified with Zr by equal volume impregnation method.The effects of different amounts of Zr on the structure of modified Y zeolite,the physicochemical properties of the catalyst and the performance of hydrocracking reaction were investigated systematically.The modified Y zeolite and catalyst were characterized by X-ray diffraction (XRD),NH3 temperature programmed desorption (NH3-TPD),H2 temperature programmed reduction (H2-TPR) and transmission electron microscopy (TEM).The results show that Zr modification decreased the amount of acid sites of Y zeolite,and the trend became larger with an increase of Zr content.Moreover,Zr modification availably weakened the relation of metal species and support in the catalyst with Y zeolite,and improved the dispersion of W species on the catalyst surface.The hydrocracking reaction results suggested that VGO conversion over the catalyst with Y zeolite modified with Zr decreased compared with that with Y zeolite,and middle distillates increased about 20%(mass),as well as VGO conversion gradually decreased and the middle distillates slightly increased as the Zr content increased.