Modeling of Catalyst Activity Profiles in Fixed-Bed Reactors with a Moment Transformation Method

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• 作者：Jonas Roininen ; Ville Alopaeus
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2008
• 出版时间：November 5, 2008
• 年：2008
• 卷：47
• 期：21
• 页码：8192-8196
• 全文大小：157K
• 年卷期：v.47,no.21(November 5, 2008)
• ISSN：1520-5045

文摘

A model for pseudo-steady-state catalyst activity profiles in a fixed-bed reactor is presented. It is based on conservation of moments of the exact catalyst activity profile, as calculated from the catalyst deactivation rate. These moments are then transformed analytically into a polynomial approximation of the activity profile for each time step. Then temporal and spatial evolution of the catalyst activity can be followed, and correspondingly accurate predictions of reactor performance with partly deactivated catalyst can be carried out. The present model is especially suitable for situations where the observed reaction rate is not solely determined by kinetics of a catalytic reaction, but also by heat or mass transfer limitations, or if the pressure drop in the reactor affects reaction rates. A further important class is when multiple reactions are taking place with different mechanisms so that the dominant mechanism changes as catalyst is deactivated. It can also be used in catalyst lifespan design, since measured temperature gradients can be followed by the model and transformed into information regarding catalyst activity profile. Also optimization of reactor operation with partly deactivated catalyst can be improved.