Modeling of Industrial Fluidized-Bed Reactors

• Published in: Industrial & engineering chemistry research 2004-09, Vol.43 (18), p.5593-5604
• Main Authors: Werther, Joachim, Hartge, Ernst-Ulrich
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical engineering; Exact sciences and technology; Reactors
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie030760t

A modeling approach is presented that is able to handle the most important aspects of industrial fluidized-bed reactors. A particular focus is to describe the relationship between catalyst attrition, solids recovery in the reactor system, and chemical performance of the fluidized-bed reactor. The competing influences of attrition of the catalyst particles and efficiency of the solids recovery lead to the etablishment of a catalyst particle size distribution in the bed inventory, which, in turn, influences via the hydrodynamic characteristics of the fluidized bed and, thereby, the performance of the chemical reactor. The usefulness of this approach is illustrated with model calculations for a fictituous first-order reaction in which the fluidized bed is equipped with different solids recovery systems including one single-stage cyclone, several cyclones in parallel, and two- and three-stage cyclone systems. Model calculations illustrate the importance of a high efficiency of solids recovery to keep the fines in the system which is decisive for a high performance of the reactor. The calculations reveal that it might take months until a quasi-steady state of the bed particle size distribution is obtained.