Isomerization of 1-butene on silica-alumina: Kinetic modeling and catalyst deactivation

Journal Article · Wed Feb 01 04:00:00 EST 1995 · AIChE Journal (American Institute of Chemical Engineers); (United States)

DOI:https://doi.org/10.1002/aic.690410211· OSTI ID:6595172

Garcia-Ochoa, F; Santos, A ^[1]

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1. Univ. Complutense, Madrid (Spain). Dept. de Ingenieria Quimica

In the study of 1-butene isomerization on a silica-alumina catalyst 448--523 K, cis-2-butene and trans-2-butene are detected. Based on BSTR experimental data and zero-time prediction kinetic models using the Langmuir-Hinshelwood mechanism are assumed to develop kinetic equations for which a triangular reaction scheme is used. In four different mechanisms, one and two active sites take part in the surface reaction as the controlling step and then the deactivation rate determined considering two types of experimental data from BSTR and by measuring weight changes of a catalyst particle from coke deposition in an electrobalance. A coke precursor is assumed formed by reaction of adsorbed molecules (of any butene isomer) and gas-phase molecules. Activity and coke-content-time data allow one to choose a model whose activation energies of the deactivation kinetic parameter are closer in value. Coke is assumed deposited in a monolayer. The model chosen shows a triangular scheme, kinetic equations of the reaction for fresh catalyst with two active sites in the surface reaction, and the deactivation rate according to a coke formation mechanism in which a precursor is formed by reaction of 3 adsorbed molecules and 1 molecule in the gas phase. It accurately fits both BSTR conversion-time data and electrobalance coke-content data. The coke formation mechanism establishes relationships of activity vs. coke content and catalyst acidity which are supported by experimental results.

• OSTI ID: 6595172
• Journal Information: AIChE Journal (American Institute of Chemical Engineers); (United States), Journal Name: AIChE Journal (American Institute of Chemical Engineers); (United States) Vol. 41:2; ISSN 0001-1541; ISSN AICEAC
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020500* -- Petroleum-- Products & By-Products
ALKENES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BUTENES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DEACTIVATION
DEPOSITS
HYDROCARBONS
ISOMERIZATION
KINETICS
MATHEMATICAL MODELS
MINERALS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SILICA
SILICON COMPOUNDS
SILICON OXIDES