Study On Preparation And Forming Process Of New RFCC Catalyst With Modified HSY Molecular Sieve As Active Component

The fluid catalytic cracking?FCC?process was commonly used in petroleum processing.With the impact of heavy and inferior crude oil quality,major refineries had gradually increased the resid-ratio in FCC feedstock oil,and the proportion of RFCC process that focuses on efficient conversion of heavy oil had also increased in FCC process.The catalytic cracking performance of heavy oil can be significantly improved by using small size Y zeolite sample with high framework SiO₂/Al₂O₃ ratio?HSY?as the active component of RFCC catalyst.In order to further improve the product distribution,HSY-LaY catalyst prepared by the small size HSY zeolite sample with high framework SiO₂/Al₂O₃ ratio was treated by phosphorus modification or ammonium exchange composited with phosphorus modification.Two series of P/HSY-LaY catalysts with different impregnation amount of phosphorus pentoxide were prepared and characterized by XRD,XRF,NH₃-TPD,and Py-IR techniques,and the heavy oil catalytic cracking activities of the modified catalysts were evaluated on a heavy oil micro reactor.Then,DUT series microsphere catalysts were prepared through industrial scale-up,the effects of different binder ratios on the heavy oil catalytic cracking performance of DUT catalysts and the propylene production performance of DUT catalysts with P1 additive were investigated.Finally,the activity and stability experiments of DUT catalysts were tested in order to meet the requirements of industrial catalysts.The results showed that:?1?Compared with catalyst L-A prepared with HSY-LaY as the active component,the L acid and B acid amount of catalyst L-B prepared by further ammonium exchanged HSY-LaY were reduced and increased respectively,the yields of LPG and gasoline were increased by 4.9wt%and 4.7 wt%respectively.?2?Phosphorus modification further improved the acidity distribution and increased catalytic activity of heavy oil catalytic cracking.1%P/L-A sample exhibited excellent heavy oil catalytic cracking performance.Its heavy oil conversion reached 93.8 wt%,while the gasoline yield was up to 54.1 wt%,the LPG yield was 11.2 wt%,and the diesel-gasoline ratio was decreased to 0.3.?3?Based on catalyst L-A and L-B,DUT microsphere catalysts were prepared by industrial scale-up with different binder ratio.Based on catalyst L-B,DUT-B4 microsphere catalyst prepared by industrial scale-up had excellent catalytic cracking performance.The yields of gasoline and LPG over DUT-B4 catalyst reached 53.2wt%and 14.8wt%,respectively.After 30hours of hydrothermal treatment,its conversion of heavy oil still maintained 88.2 wt%with a gasoline+LPG yield of 59.1 wt%.The stability can satisfy the demand on the industrial application.?4?The yield of propylene was increased significantly after adding 5 wt%P1 additive to DUT-B4.The yields of propylene and LPG reached 7.8 wt%and 27.5 wt%respectively.The conversion of heavy oil and the yield of gasoline reached 96.9wt%and 48.3 wt%respectively.It's heavy oil conversion,propylene yield and gasoline+LPG yield are higher than the industrial agent in different hydrothermal aging time.