The complete oxidation of hydrocarbons with various structures (methane, n- and iso-pentanes, cyclohexane, and benzene) on copper-modified ZSM-5 zeolite and the aromatization of propane on H-ZSM-5, are studied to analyze diffusion effects on the reaction kinetics. Comparison of the kinetic parameters of com- plete oxidation shows that the process rate and the rate law strongly depend on the reactant structure. Appar- ently, n-pentane oxidation is controlled by kinetics; the kinetics for other hydrocarbons depends on diffusion inside zeolite channels to different degrees. In the case of propane aromatization, its dehydrogenation and cracking, as well as the formation of aromatics from olefins, occurs on different active sites. Propane conversion is supposed to occur inside the zeolite channels, and the aromatization of olefins occurs on the outer surface of the zeolite crystal.
Kinetics of hydrocarbons transformations over ZSM-5 zeolites
BOTAVINA, Maria;
2000-01-01
Abstract
The complete oxidation of hydrocarbons with various structures (methane, n- and iso-pentanes, cyclohexane, and benzene) on copper-modified ZSM-5 zeolite and the aromatization of propane on H-ZSM-5, are studied to analyze diffusion effects on the reaction kinetics. Comparison of the kinetic parameters of com- plete oxidation shows that the process rate and the rate law strongly depend on the reactant structure. Appar- ently, n-pentane oxidation is controlled by kinetics; the kinetics for other hydrocarbons depends on diffusion inside zeolite channels to different degrees. In the case of propane aromatization, its dehydrogenation and cracking, as well as the formation of aromatics from olefins, occurs on different active sites. Propane conversion is supposed to occur inside the zeolite channels, and the aromatization of olefins occurs on the outer surface of the zeolite crystal.
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