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采用原位晶化法制备含磷的PY型分子筛,并用X射线衍射(XRD)、程序升温氨脱附(NH3-TPD)等测试方法对磷改性的PY型分子筛进行了表征。结果表明,磷的引入不影响分子筛的晶形,分子筛的相对结晶度变化很小,晶胞收缩,晶胞常数减小;分子筛的硅铝摩尔比(简称硅铝比,下同)增大。适量磷(质量分数0.1%)的引入降低了催化剂的总酸量、弱酸量和强酸量,增加了催化剂的中强酸的酸量。因此,可以有效调变催化剂的酸量和酸强度。在小型固定流化床装置上对催化剂的反应性能进行评价,发现与Y型催化剂相比,PY型催化剂在总液收提高了2.35%的条件下,使重油产率降低了0.32%,焦炭产率降低了0.22%,同时汽油收率和轻油收率分别提高了1.75%和1.68%,表现出很强的重质油转化能力和良好的裂化产物选择性。
Phosphorus-containing PY zeolites were prepared by in-situ crystallization. The phosphorus-modified PY zeolites were characterized by X-ray diffraction (XRD) and temperature-programmed ammonia desorption (NH3-TPD) The results show that the introduction of phosphorus does not affect the crystalline form of molecular sieve. The relative crystallinity of the molecular sieve changes little, the unit cell shrinks and the unit cell constant decreases. The mole ratio of Si / Al (Si / Al, the same below) increases. The introduction of the appropriate amount of phosphorus (0.1%) reduced the total acid amount, weak acid amount and strong acid amount of the catalyst, and increased the acid amount of the medium strong acid of the catalyst. Therefore, it is possible to effectively adjust the acid amount and the acid strength of the catalyst. The performance of the catalyst was evaluated in a small fixed fluidized bed reactor and found that the PY-type catalyst reduced the yield of heavy oil by 0.32% when the total liquid collection increased by 2.35% compared with the Y-type catalyst. The coke yield 0.22% lower gasoline yield and light oil yield increased by 1.75% and 1.68%, respectively, showing strong heavy oil conversion capacity and good cracking product selectivity.