Rao, SM;
Saraçi, E;
Gläser, R;
Coppens, MO;
(2017)
Surface barriers as dominant mechanism to transport limitations in hierarchically structured catalysts – Application to the zeolite-catalyzed alkylation of benzene with ethylene.
Chemical Engineering Journal
, 329
pp. 45-55.
10.1016/j.cej.2017.04.015.
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Abstract
The meso-macropore network of a hierarchically structured zeolite catalyst is numerically optimized to maximize the volume-integrated reaction yield in the ethylation of benzene to produce ethylbenzene over zeolite H-ZSM-5. A hierarchical approach is used at multiple length scales to determine the optimal pore network properties. The maximum volume-integrated reaction yield of the hierarchically structured zeolite catalyst containing meso- and macropores is nearly twice the yield of a zeolite pellet containing only macropores, at the same macroporosity. To bridge the gap between modeling and experiments, a series of physical mixtures of ZSM-5 crystals and mesoporous silica, containing different weight fractions of zeolite is synthesized and used in fixed bed reactor experiments to determine the optimal pellet structure to maximize the conversion of ethylene. Comparison with reactor simulations of the zeolite composites shows that the performance of the zeolite composites might be limited by surface barriers at the external surface of the zeolite crystals, rather than by diffusion limitations within the meso-macropore network of the pellets.
| Type: | Article |
|---|---|
| Title: | Surface barriers as dominant mechanism to transport limitations in hierarchically structured catalysts – Application to the zeolite-catalyzed alkylation of benzene with ethylene |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.cej.2017.04.015 |
| Publisher version: | http://dx.doi.org/10.1016/j.cej.2017.04.015 |
| Language: | English |
| Additional information: | Copyright © 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/). |
| Keywords: | Surface barriers; Diffusion; Meso-macropore network; Zeolites; Rational catalyst design; Benzene alkylation |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1555516 |
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