Revisiting the concepts of competition between reaction and diffusion in poisoned catalysts

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Luís M. Madeira (Author) FEUP; Alírio E. Rodrigues (Author) FEUP

Journal

Title: Canadian Journal of Chemical Engineering

Vol. 91 No. 2

Pages: 203-211

ISSN: 0008-4034

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 1 Citation

ISI Web of Science

Scopus - 1 Citation

Scientific classification

FOS: Engineering and technology > Chemical engineering

CORDIS: Technological sciences > Engineering > Chemical engineering

Other information

Authenticus ID: P-002-12G

DOI: 10.1002/cjce.21759

Abstract (EN): The competition between diffusion and first-order irreversible reaction in poisoned catalysts is revisited. Two cases are considered for isothermal slab catalysts: uniform and shell-progressive (or pore-mouth) poisoning. Analytical concentration profiles are derived, and the implications on catalyst performance are evaluated in different regimes (chemical- or diffusion-controlled) for different levels of poisoning. It was found that depending on the poisoning mechanism, the activity decay can be more or less pronounced. Being of particular concern is the pore-mouth poisoning at high Thiele modulus, conditions under which catalyst performance is drastically affected. The reagent concentration profiles allowed the explanation of the phenomena occurring at the particle scale, in particular the effectiveness factors, observed reaction rates, and poisoning factors' dependence on the Thiele modulus and fraction of the poisoned catalyst; it was found that such relationships are dependent on the mechanism of deactivation. (c) 2012 Canadian Society for Chemical Engineering

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9