![Isomerization of n-butane to isobutane over Pt-modified Beta and ZSM-5 zeolite catalysts: Catalyst deactivation and regeneration [An article from: Chemical Engineering Journal]](https://www.ebooknetworking.net/books/B00/0RR/bigB000RR96OC.jpg)
Isomerization of n-butane to isobutane over Pt-modified Beta and ZSM-5 zeolite catalysts: Catalyst deactivation and regeneration [An article from: Chemical Engineering Journal]
Description
This digital document is a journal article from Chemical Engineering Journal, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
This work addresses the deactivation behavior of H-Beta, H-ZSM-5, Pt-Beta and Pt-ZSM-5 catalysts in the isomerization of n-butane to isobutane. Furthermore, the type of coke formed inside these catalysts was characterized. The regeneration of Pt-Beta and Pt-ZSM-5 with synthetic air was also investigated. Most of the coke was formed during the first 70min of TOS. Linear long-chain olefins formed the soluble coke, which was mainly determined by the reactant molecule and formed by consecutive oligomerization of n-butane molecules. On the other hand, the amount of insoluble coke is influenced by the reaction conditions, carrier gas and, most of all, zeolite structure. Pt and hydrogen inhibit successive reactions, i.e. alkylation, cyclization, that soluble coke undergoes before becoming insoluble. The beneficial effect of coke on the shape selectivity was observed, which increased the isomerization efficiency, defined as IE=iC"4/(iC"4+C"3+C"5). The activity on Pt-Beta was completely restored by oxidative regeneration, showing a higher IE than the fresh one.
Description:
This work addresses the deactivation behavior of H-Beta, H-ZSM-5, Pt-Beta and Pt-ZSM-5 catalysts in the isomerization of n-butane to isobutane. Furthermore, the type of coke formed inside these catalysts was characterized. The regeneration of Pt-Beta and Pt-ZSM-5 with synthetic air was also investigated. Most of the coke was formed during the first 70min of TOS. Linear long-chain olefins formed the soluble coke, which was mainly determined by the reactant molecule and formed by consecutive oligomerization of n-butane molecules. On the other hand, the amount of insoluble coke is influenced by the reaction conditions, carrier gas and, most of all, zeolite structure. Pt and hydrogen inhibit successive reactions, i.e. alkylation, cyclization, that soluble coke undergoes before becoming insoluble. The beneficial effect of coke on the shape selectivity was observed, which increased the isomerization efficiency, defined as IE=iC"4/(iC"4+C"3+C"5). The activity on Pt-Beta was completely restored by oxidative regeneration, showing a higher IE than the fresh one.
