Self Diffusivity of n-Dodecane and Benzothiophene in ZSM-5 Zeolites: Its Significance for a New Catalytic Light Diesel Desulfurization Process
This study provides theoretical support to a recent promising ZSM5 catalyst used for the selective desulfurization of light diesel type compounds (Al-Bogami and de Lasa 2013; Al-Bogami, Moreira, and de Lasa 2013). With this end, Molecular Dynamics (MD) simulations employing a rigid silicalite struct...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2016 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/77396 |
| Acceso en línea: | http://hdl.handle.net/11336/77396 |
| Access Level: | acceso abierto |
| Palabra clave: | Catalyst Desulfurization Diesel Molecular Simulation Self Diffusion Zeolite https://purl.org/becyt/ford/2.4 https://purl.org/becyt/ford/2 |
| Sumario: | This study provides theoretical support to a recent promising ZSM5 catalyst used for the selective desulfurization of light diesel type compounds (Al-Bogami and de Lasa 2013; Al-Bogami, Moreira, and de Lasa 2013). With this end, Molecular Dynamics (MD) simulations employing a rigid silicalite structure are developed to calculate self-diffusivities of n-Dodecane (n-C12) and Benzothiophene (BZT) in a silicalite structure. The simulations are performed at 573 K, 623 K, 673 K and 723 K at a fixed loading of 1 molecule per unit cell to study the temperature effect on diffusivity coefficient. In addition, a number of simulations which are developed to investigate four molecule loadings (corresponding to 0.25, 0.5, 0.75 and 1 molecule per zeolite unit cell) at 723 K. MD simulations, show a self diffusivity of BZT one order of magnitude higher than that of n-C12 self diffusivity at all temperatures investigated. This is the case in spite of BZT having a critical molecular diameter of 6 Å when compared to the 4.9 Å diameter of n-C12. In addition, the self diffusivity coefficient is found to increase with temperature for both n-C12 and BZT. Furthermore, the results obtained show that the self diffusivity of n-C12 decreases as the number of n-C12 molecules per zeolite unit cell increases. On the other hand, it is observed that the self-diffusivity coefficient for BZT remains fairly constant and drops at a loading of 1 molecule per zeolite unit cell only. These coefficients show that differences in n-C12 and benzothiophene diffusivities favours desulfurization with selective benzothiophene adsorption and sulfur species removal as coke (Al-Bogami and de Lasa 2013). |
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