MFI结构分子筛硅铝比对催化裂化汽油辛烷值桶的影响

采用复合酸化学抽铝的方法制备了不同硅铝比的MFI结构分子筛并对其物化性质进行了表征。结果表明:以该方法制备的高硅铝比MFI结构分子筛结晶度高、比表面积大、孔体积大、总酸中心密度低,强酸在总酸中的比例高,B酸在总酸中的比例高;磷改性后的高硅铝比MFI结构分子筛水热稳定性好,将其制成助剂后添加到催化裂化催化剂体系中,可以在不降低汽油收率的前提下有效提高催化裂化汽油的辛烷值桶。

EFFECT OF Si/Al RATIO OF MFI TYPE ZEOLITE ON FCC GASOLINE OCTANE BARREL

The MFI type zeolites with different Si/Al ratios were prepared by dealumination with compound acid and characterized. The results showed that the MFI zeolites with higher Si/Al ratio prepared by this method have a higher crystallinity, larger surface area and pore volume, lower total acid density, as well as higher proportion of strong acid and Bronsted acid to total acid number. The high Si/Al ratio MFI structure zeolites modified by phosphorus show an excellent hydrothermal stability. When the phosphorus modified zeolites were used as additives and added into FCC catalyst system, the gasoline octane barrel could be enhanced effectively while no gasoline yield was lost.