Catalyst Deactivation in 3D CFD Resolved Particle Simulations of Propane Dehydrogenation

• Published in: Industrial & engineering chemistry research Vol. 49; no. 21; pp. 10641 - 10650
• Main Authors: Behnam, Mohsen, Dixon, Anthony G, Nijemeisland, Michiel, Stitt, E. Hugh
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Washington, DC American Chemical Society 03.11.2010
• Subjects: Applied sciences; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Exact sciences and technology; General and physical chemistry; Kinetics, Catalysis, and Reaction Engineering; Reactors; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Deactivation; Computational fluid dynamics; Dehydrogenation; Catalyst
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie100456k

Catalyst deactivation by carbon deposition has been investigated for the dehydrogenation of propane to propene on a Cr2O3/Al2O3 catalyst. Computational fluid dynamics was used to couple the 3D transport and reaction processes occurring inside the cylindrical pellet to the gas flow around the pellet. The pellet scale reaction and carbon laydown are shown to be strongly affected by the bed scale tube wall heat flux supplied for the endothermic reactions, and the species distributions on the pellet surface are also affected by the ease of reactant access to the particle. The development of particle internal gradients and carbon accumulation are illustrated for the early stages of deactivation. Carbon deposition is initially strongest in the high temperature regions close to the tube wall. As time progresses, the increased deactivation caused by the carbon acts to reduce all rates of reaction, and propene production and coke formation shift to other regions of the pellet.