水汽和空气焙烧制备LaY沸石的SiCl4气相超稳研究

为了考察不同焙烧条件制备的LaY沸石在SiCl₄气相超稳后性能的差异，采用离子交换和氨水沉淀相结合的方法将La离子负载到NaY沸石上，经水蒸汽焙烧或空气焙烧得到不同La负载量的LaYS和LaYB沸石，再经过SiCl₄气相超稳改性得到DLaYS和DLaYB沸石.XRD数据表明水蒸汽焙烧能使沸石发生更为明显的骨架脱铝；不同La负载量的LaY沸石经SiCl₄气相超稳改性都能顺利实现晶胞收缩.XRF数据表明气相超稳和洗涤过程伴随着稀土La的大量流失，DLaYB沸石中的La流失量相对较小.NH₃-TPD和Py-IR数据表明La负载量相同时，DLaYS沸石的总酸量少于DLaYB沸石的总酸量.固定流化床重油催化裂化评价结果显示，与参比催化剂相比，DLaYS催化剂和DLaYB催化剂都具有汽油收率高、柴油收率低，及总轻质油收率高的特点.La负载量相同时，DLaYS催化剂的汽油收率低于DLaYB催化剂.

SiCl4 Vapor Treatment of LaY Zeolite Prepared by Steam and Air Calcination

In order to investigate the difference of performances of LaY zeolites prepared by different calcination condition and SiCl₄ vapor treatment, La ions were loaded onto NaY zeolite through the combination of ion exchange and ammonia deposition. LaYS zeolites and LaYB zeolites containing different La content, were obtained respectively by steam calcination or air calcination, and then, DLaYS zeolites or DLaYB zeolites were obtained by SiCl₄ vapor treatment. XRD data showed that more obvious dealuminization happened under steam calcination; besides, shrinkage of cell parameters of LaY zeolites containing different La content could be successfully achieved undergoing SiCl₄ vapor treatment. XRF data showed that underwent two processes of SiCl₄ vapor treatment and washing, a large number of rare earth La content lost. However, the loss of La content in DLaYB zeolites are relatively less than that of DLaYS zeolites.NH₃-TPD and Py-IR data showed under the condition that La content is same, the total acid content of DLaYS zeolites were less than that of DLaYB zeolites. The results of fixed fluidized bed catalytic cracking reaction evaluation showed that both DLaYS catalysts and DLaYB catalysts have higher gasoline yield, lower LCO yield, and higher light oil yield than that of reference catalysts. When La content is same, the gasoline yield of DLaYS catalysts were lower than that of DLaYB catalysts.