Isobutane cracking over Y-zeolites: I. Development of a kinetic model
- Univ. of Wisconsin, Madison, WI (United States); and others
The authors have developed a kinetic model for isobutane cracking over calcined and steamed Y-zeolite catalysts based on carbo-cation surface chemistry. The model utilized 21 reaction steps, including initiation, oligomerization, {beta}-scission, olefin desorption, isomerization, and hydride ion transfer, which adequately described the formation of all major products. The authors estimated kinetic parameters using transition state theory, the Evans-Polanyi correlation, and gas phase thermodynamic data. In order to relate the gas phase calculations to the catalyst surface, the authors introduced a parameter {triangle}H{sub +}, which is the heat of stabilization of a carbenium ion relative to the heat of stabilization of a proton in the zeolite framework. The model provided a good description of the experimental data for calcined and steamed catalysts with physically realistic kinetic parameters. The main difference between the two catalysts was the higher {triangle}H{sub +} for the steamed catalyst. This indicates that steaming decreased the Broensted acid strength of the catalyst. 60 refs., 7 figs., 7 tabs.
- DOE Contract Number:
- FG02-84ER13183
- OSTI ID:
- 98946
- Journal Information:
- Journal of Catalysis, Vol. 153, Issue 1; Other Information: PBD: 15 Apr 1995
- Country of Publication:
- United States
- Language:
- English
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