氟硅酸铵改性对小晶粒Y分子筛加氢裂化性能的影响

EFFECT OF(NH_(4))_(2)SiF_(6) MODIFIED SMALL CRYSTAL-SIZE Y ZEOLITE ON HYDROCRACKING PERFORMANCE

采用氟硅酸铵对小晶粒Y分子筛进行改性处理,考察了氟硅酸铵不同加入方式对小晶粒Y分子筛物化性质和加氢裂化性能的影响。实验结果表明,与氟硅酸铵一次性加入相比,采用分步加入方式得到的小晶粒Y分子筛相对结晶度增加,比表面积和硅铝比增大,而酸量降低。氟硅酸铵两步等量(1∶1)加入处理得到的小晶粒Y分子筛试样的相对结晶度最高,比表面积和硅铝比最大,B酸/L酸比值也最大。其C_(4)~C_(8)组分的选择性最高(61.14%),较氟硅酸铵一次性加入处理得到的分子筛试样提高约1.5%。

Small crystal-size Y-type zeolite was modified with(NH_(4))_(2)SiF_(6).The effects of different dropping modes of(NH_(4))_(2)SiF_(6) on the physicochemical properties and hydrocracking performances of small crystal-size Y-type zeolite were investigated.Experimental results showed that the relative crystallinity,specific surface area,and Si/Al ratio of small crystal-size Y-type zeolite obtained by two-step dropwise addition treatment are all increased,while the acid amount decreases,compared with the one-time addition of(NH_(4))_(2)SiF_(6).The small crystal-size Y-type zeolite obtained by two-step dropwise addition of the equal amount of(NH_(4))_(2)SiF_(6) has the highest relative crystallinity,Si/Al molar ratio,and B/L acidity ratio.It also exhibites the highest selectivity for the C_(4)C_(8) components(61.14%),which is about 1.5%higher than the zeolite sample obtained by one-time addition of(NH_(4))_(2)SiF_(6).