High silica REHY zeolite with low rare earth loading as high-performance catalyst for heavy oil conversion
High silica REHY zeolite with low rare earth loading as high-performance catalyst for heavy oil conversion
复制标题
低稀土负载量高硅REHY沸石作为高性能重油转化催化剂
DOI：
10.1016/j.apcata.2011.11.015
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发表时间：
2012-01-31
影响因子：
5.5
通讯作者：
Shen, Baojian
中科院分区：
文献类型：
--
作者：
Gao, Xionghou;Qin, Zhengxing;Shen, Baojian
研究了骨架SiO_2/Al_2O_3分别为5.8、4.8和4.6的高硅、普通硅和低硅NaY分子筛的稀土交换性能。发现起始NaY沸石的硅含量是决定离子交换效率的重要因素之一。骨架SiO_2/Al_2O_3比值越高，沸石对稀土离子的选择性越低。然而，当离子交换溶液中稀土的浓度小于6重量%时，稀土离子的使用效率彼此相当，无论起始沸石的骨架SiO2/Al 2 O3比率的水平如何。对稀土和铵交换沸石（REHY）的水热稳定性的比较表明，由高硅NaY和最低稀土负载量（2.9wt.%）制备的REHY样品具有最佳的水热稳定性。表现出最好的水热稳定性。反应研究表明，含该REHY沸石的催化剂在重油催化转化中显示出比由普通硅NaY沸石制备的具有高达6.6wt.%的稀土负载量的另一种REHY沸石好得多的活性和产物选择性，这很可能是由于前者沸石的上级水热稳定性优异。由高硅NaY制备的低稀土负载量REHY分子筛可作为柴油催化转化的替代催化剂。(C)2011爱思唯尔有限公司版权所有。
Study on the rare earth exchange performance was carried out with high silica, normal silica and low silica NaY zeolites with framework SiO2/Al2O3 ratios of 5.8, 4.8 and 4.6, respectively. It is found that the silicon content of the starting NaY zeolite is one of the significant factors in determining the ion exchange efficiency. The higher the framework SiO2/Al2O3 ratio is, the less selective to the rare earth ions the zeolite will be. However, the efficiency of the use of rare earth ions are comparable to each other when the concentration of rare earth in the ion exchange solution is less than 6 wt.%, no matter the level of the framework SiO2/Al2O3 ratio of the starting zeolites. Comparison of the hydrothermal stability of the rare earth and ammonium exchanged zeolites (REHY) indicates that the REHY sample prepared from the high silica NaY and with the lowest rare earth loading (2.9 wt.%) exhibits the best hydrothermal stability. The reaction studies indicate that the catalyst containing this REHY zeolite shows much better activity and product selectivity in the catalytic conversion of heavy oil than another REHY zeolite prepared from the normal silica NaY zeolite and having a rare earth loading as high as 6.6 wt.%, which is highly probably due to the superior hydrothermal stability of the former zeolite. It is suggested that the REHY zeolite with a low level of rare earth loading prepared from the high silica NaY can be considered as an alternative catalyst for the catalytic conversion of gas oil. (C) 2011 Elsevier B.V. All rights reserved.