The use of MCM-22 as a cracking zeolitic additive for FCC
The use of MCM-22 as a cracking zeolitic additive for FCC
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DOI：
10.1006/jcat.1997.1474
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发表时间：
1997-01-01
影响因子：
7.3
通讯作者：
MartinezTriguero, J
中科院分区：
文献类型：
--
作者：
Corma, A;MartinezTriguero, J
在MCM-22分子筛上进行了柴油催化裂化反应。该沸石与所提出的结构一致，显示出对裂解真空瓦斯油进料中存在的大分子的小活性。然而，当它与USY基裂化催化剂组合用作裂化添加剂时，并将其行为与ZSM-5沸石添加剂的行为进行比较，发现MCM-22产生较少的总气体以及较少的干气体，汽油损失低于ZSM-5。另一方面，在MCM-22的情况下，丙烯与丙烷和丁烯与丁烷的比率更高，在生产新配方汽油的框架内显示出非常适当的行为。然而，ZSM-5比MCM-22更有活性，并且在低添加率（类似于3重量%）下，ZSM-5显示出比MCM-22更大的效果。为了看到MCM-22作为裂化添加剂的益处，需要引入更大的量（类似于13重量%）。ZSM-5比MCM-22具有更高的质子裂解/β-裂解比率，MCM-22的水蒸气稳定性相当好，甚至高于ZSM-5。最后，我们提出了一种方法来测试添加剂在瓦斯油裂化，提高他们的效果，使我们能够非常清楚地显示沸石添加剂的裂化行为。(C)出版社：Academic Press，Inc.
The catalytic cracking of gasoil has been carried out on a MCM-22 zeolite sample. This zeolite, in agreement with the proposed structure, shows little activity for cracking the large molecules present in the vacuum gasoil feed. However, when it is used as a cracking additive in combination with a USY based cracking catalyst, and its behaviour is compared with that of a ZSM-5 zeolite additive, it is found that MCM-22 produces less total gases, as well as less dry gases, with a lower loss of gasoline than ZSM-5. On the other hand, the propylene to propane and butene to butane ratio is higher in the case of MCM-22, showing a very adequate behaviour within the frame of the production of reformulated gasolines. However, ZSM-5 is more active than MCM-22 and at low rates of addition, similar to 3 wt%, ZSM-5 shows a larger effect than MCM-22. In order to see the benefits of MCM-22 as a cracking additive, larger amounts (similar to 13 wt%) need to be introduced. ZSM-5 gives a higher ratio of protolytic to beta-scission cracking than MCM-22, and the steam stability of MCM-22 is quite good, being even higher than that of ZSM-5. Finally, we present a method for testing additives during gasoil cracking which enhances their effects and allows us to show very clearly the cracking behaviour of zeolite additives. (C) 1997 Academic Press, Inc.