Modeling Catalyst Deactivation in Dehydrogenation of Ethylbenzene to Styrene<br/>

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Modeling Catalyst Deactivation in Dehydrogenation of Ethylbenzene to Styrene

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Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 41121 (06)
University: Sharif University of Thechnology
Department: Chemical and Petroleum Engineering
Advisor(s): Baghghalha, Morteza; Ghotbi, Siroos
Abstract:
Long-term deactivation of a commercial K-promoted Fe2O3 catalyst used in the dehydrogenation of ethylbenzene to styrene monomer was studied using thirty months of operating data of three industrial SM radial fixed bed adiabatic reactors. The Langmuir-Hinshelwood, Hougen-Watson model (LHHW) was used for reaction kinetics modeling. The kinetics of coking from ethylbenzene and styrene and the short-term deactivation function due to the quick coke formation were also considered in the model. The kinetics of long-term deactivation of the catalyst for ethylbenzene dehydrogenation to styrene between 550 and 630 °C were determined by allowing the effects of temperature and time on the catalyst activity. Using the plant data, 5 unknown parameters of the long-term activity function, related to the slow loss of potassium from the catalyst, were optimized. The optimized value of the order of the deactivation law was determined to be three. The effect of internal mass-transport limitation was found to be minimal.
Keywords:
Ethylbbenzen ; Catalyst Deactivation ; Dehydrogenation ; Styrene ; Polystyrene ; Potassium Promoter Iron Oxide

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