Dead-core solutions to simple catalytic reaction problems in chemical engineering

F. Sabit, M. Shakipov, Piotr Sebastian Skrzypacz, Boris Golman

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The catalytic chemical reaction is usually carried out in a pellet where the catalyst is distributed throughout its porous structure. The selectivity, yield and productivity of the catalytic reactor often depend on the rates of chemical reactions and the rates of diffusion of species involved in the reactions in the pellet porous space. In such systems, the fast reaction can lead to the consumption of reactants close to the external pellet surface and creation of the dead core where no reaction occurs. This will result in an inefficient use of expensive catalyst. In the discussed simplified diffusion-reaction problems a nonlinear reaction term is of power-law type with a small positive reaction exponent. Such reaction term represents the kinetics of catalytic reaction accompanied by a strong adsorption of the reactant. The ways to calculate the exact solutions possessing dead cores are presented. It was also proved analytically that the exact solution of the nonlinear two-point boundary value problem satisfies physical a-priori bounds. Furthermore, the approximate solutions were obtained using the orthogonal collocation method for pellets of planar, spherical and cylindrical geometries. Numerical results confirmed that the length of the dead core increases for the more active catalysts due to the larger values of the reaction rate constant. The dead core length also depends on the pellet geometry.

Original languageEnglish
Pages (from-to)29-33
Number of pages5
JournalEurasian Chemico-Technological Journal
Volume21
Issue number1
DOIs
Publication statusPublished - Jan 1 2019

Fingerprint

chemical engineering
Chemical engineering
Catalysts
pellets
Chemical reactions
Geometry
Boundary value problems
Reaction rates
Rate constants
Productivity
catalysts
Adsorption
chemical reactions
Kinetics
collocation
geometry
productivity
boundary value problems
reaction kinetics
selectivity

Keywords

  • Collocation method
  • Dead-core
  • Diffusion-reaction
  • Exact solution
  • Strong adsorption

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Dead-core solutions to simple catalytic reaction problems in chemical engineering. / Sabit, F.; Shakipov, M.; Skrzypacz, Piotr Sebastian; Golman, Boris.

In: Eurasian Chemico-Technological Journal, Vol. 21, No. 1, 01.01.2019, p. 29-33.

Research output: Contribution to journalArticle

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