Dead-Core Solutions to Simple Catalytic Reaction Problems in Chemical Engineering
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...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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al-Farabi Kazakh National University
2019-02-01
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| Series: | Eurasian Chemico-Technological Journal |
| Subjects: | |
| Online Access: | http://ect-journal.kz/index.php/ectj/article/view/784 |
| _version_ | 1811260880728358912 |
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| author | F. Sabit M. Shakipov P. Skrzypacz B. Golman |
| author_facet | F. Sabit M. Shakipov P. Skrzypacz B. Golman |
| author_sort | F. Sabit |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-12T18:54:18Z |
| format | Article |
| id | doaj.art-cac2b24141e44fb291bf83dd3392bff0 |
| institution | Directory Open Access Journal |
| issn | 1562-3920 2522-4867 |
| language | English |
| last_indexed | 2024-04-12T18:54:18Z |
| publishDate | 2019-02-01 |
| publisher | al-Farabi Kazakh National University |
| record_format | Article |
| series | Eurasian Chemico-Technological Journal |
| spelling | doaj.art-cac2b24141e44fb291bf83dd3392bff02022-12-22T03:20:23Zengal-Farabi Kazakh National UniversityEurasian Chemico-Technological Journal1562-39202522-48672019-02-01211293310.18321/ectj784784Dead-Core Solutions to Simple Catalytic Reaction Problems in Chemical EngineeringF. Sabit0M. Shakipov1P. Skrzypacz2B. Golman3Nazarbayev University, Kabanbay Batyr Ave. 53, Astana, KazakhstanNazarbayev University, Kabanbay Batyr Ave. 53, Astana, KazakhstanNazarbayev University, Kabanbay Batyr Ave. 53, Astana, KazakhstanNazarbayev University, Kabanbay Batyr Ave. 53, Astana, KazakhstanThe 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.http://ect-journal.kz/index.php/ectj/article/view/784diffusion-reactiondead-corestrong adsorptionexact solutioncollocation method |
| spellingShingle | F. Sabit M. Shakipov P. Skrzypacz B. Golman Dead-Core Solutions to Simple Catalytic Reaction Problems in Chemical Engineering Eurasian Chemico-Technological Journal diffusion-reaction dead-core strong adsorption exact solution collocation method |
| title | Dead-Core Solutions to Simple Catalytic Reaction Problems in Chemical Engineering |
| title_full | Dead-Core Solutions to Simple Catalytic Reaction Problems in Chemical Engineering |
| title_fullStr | Dead-Core Solutions to Simple Catalytic Reaction Problems in Chemical Engineering |
| title_full_unstemmed | Dead-Core Solutions to Simple Catalytic Reaction Problems in Chemical Engineering |
| title_short | Dead-Core Solutions to Simple Catalytic Reaction Problems in Chemical Engineering |
| title_sort | dead core solutions to simple catalytic reaction problems in chemical engineering |
| topic | diffusion-reaction dead-core strong adsorption exact solution collocation method |
| url | http://ect-journal.kz/index.php/ectj/article/view/784 |
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