Restrictive liquid-phase diffusion and reaction in bidisperse catalysts
| Autor: | S. Y. Lee, J. D. Seader, F.E. Massoth, Chung H. Tsai |
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| Rok vydání: | 1991 |
| Předmět: | |
| Zdroj: | Industrial & Engineering Chemistry Research. 30:1683-1693 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/ie00056a002 |
| Popis: | In this paper, the effect of bidispersed pore-size distribution on liquid-phase diffusion and reaction in NiMo/Al{sub 2}O{sub 3} catalysts is investigated by applying two bidispersed-pore-structure models, the random-pore model and a globular-structure model, to extensive experimental data, which were obtained from sorptive diffusion measurements at ambient conditions and catalytic reaction rate measurements on nitrogen-containing compounds. Transport of the molecules in the catalysts was found to be controlled by micropore diffusion, in accordance with the random-pore model, rather than macropore diffusion as predicted by the globular-structure model. A qualitative criterion for micropore-diffusion control is proposed: relatively small macroporosity and high catalyst pellet density. Since most hydrotreating catalysts have high density, diffusion in these types of catalysts may be controlled by micropore diffusion. Accordingly, it is believed in this case that increasing the size of micropores may be more effective to reduce intraparticle diffusion resistance than incorporating macropores alone. |
| Databáze: | OpenAIRE |
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