Competitive reaction in intrazeolitic media is illustrated by the hydroisomerization of hexanes over Pt/Mordenite and Pt/Y, in the presence of an aromatic cofeed. The aromatic inhibits the paraffin reaction, changes the relative reactivities of the different hexane isomers and modifies isomer product distributions. Preferential adsorption by the aromatic modifies catalytic site distributions available for the paraffin reaction, and may also affect diffusional characteristics in the pores of the zeolite Concepts of bifunctional reaction mechanisms and carbenium ion theory are used to explain the mechanism of hexane isomerization and to establish the nature of the reaction network. Based on such mechanistic criteria, the isomer distribution in the presence of an aromatic is rationalized as a consequence of coreactant induced size and shape selectivity modifications to the catalyts The isomerization kinetics are modeled using reaction network analysis to obtain first order rate constants for each individual step of the reaction network. The results indicate that inhibition of the hexane reaction due to the presence of the aromatic affects every step in the reaction network. A generalized framework of transport and reaction in the pores of the zeolite is presented to justify the observed modifications to reaction rates and selectivities / acase@tulane.edu
| Identifer | oai:union.ndltd.org:TULANE/oai:http://digitallibrary.tulane.edu/:tulane_23852 |
| Date | January 1987 |
| Contributors | Chen, Jan-Ku Michael (Author), John, Vijay T (Thesis advisor) |
| Publisher | Tulane University |
| Source Sets | Tulane University |
| Language | English |
| Detected Language | English |
| Rights | Access requires a license to the Dissertations and Theses (ProQuest) database., Copyright is in accordance with U.S. Copyright law |
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