Y/ASA复合材料的制备及加氢裂化性能

采用原位包覆技术制备了无定形硅铝(ASA)包覆Y型分子筛的Y/ASA复合材料。分别以Y/ASA复合材料和工业Y分子筛与ASA的机械混合材料Y-ASA为载体,Ni-W为活性组分,制备了两种负载型催化剂,并考察了两种催化剂的加氢裂化性能,通过XRD、SEM、吸附吡啶的原位红外光谱和N₂吸附-脱附对载体和催化剂进行了表征。结果表明,Y/ASA载体和Ni-W/Y/ASA的总酸量较低,但强酸量和强弱酸比例均高于Y-ASA和Ni-W/Y-ASA,Y/ASA载体和Ni-W/Y/ASA催化剂拥有更大的介孔比表面积、孔容及平均孔径。正癸烷的加氢裂化反应结果表明,Ni-W/Y/ASA催化剂上正癸烷的转化率和中间组分(C_5~9)收率比Ni-W/Y-ASA催化剂分别高7.6 %和12.4 %。

Synthesis and hydrocracking performance of Y/ASA composite

In-situ covering technology was used to prepare the Y/ASA composite material in which Y zeolite was covered around with amorphous silica-alumina(ASA).Two kinds of supported Ni-W catalysts for hydrocracking of decane were prepared using Y/ASA and Y-ASA as supports,respectively.Y-ASA was a kind of mechanical mixture of industrial Y zeolite and ASA.The supports and catalysts were characterized by X-ray powder diffraction,scanning electron microscopy,infrared spectroscopy of pyridine adsorption and N2 adsorption-desorption.The results showed that,while there were less total acid sites on Y/ASA and Ni-W/Y/ASA,there were more strong acid sites.The ratios of strong acid sites to weak acid sites of Y/ASA and Ni-W/Y/ASA were higher than those of Y-ASA and Ni-W/Y-ASA.The average pore diameter,mesopore surface area and pore volume of Y/ASA and Ni-W/Y/ASA were larger than those of the comparative samples,respectively.The hydrocracking of decane over the Ni-W/Y/ASA catalyst revealed that the conversion and yield of middle-component(C5~9) were improved by 7.6 % and 12.4 %,respectively,compared with that over Ni-W/Y-ASA catalyst.