Scaling of a catalytic cracking fluidized bed downer reactor based on computational fluid dynamics simulations
| Autor: | Supawadee Ratchasombat, Parinya Khongprom, Waritnan Wanchan, Sunun Limtrakul, Panut Bumphenkiattikul |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Plug flow
Materials science business.industry General Chemical Engineering 02 engineering and technology General Chemistry Mechanics Computational fluid dynamics 021001 nanoscience & nanotechnology Fluid catalytic cracking 020401 chemical engineering Fluidized bed Mass transfer Fluidized bed combustion 0204 chemical engineering Downer 0210 nano-technology business Mass fraction |
| Zdroj: | RSC Advances. 10:2897-2914 |
| ISSN: | 2046-2069 |
| Popis: | Circulating fluidized bed downer reactors (downer reactors) exhibit good heat and mass transfer, and the flow behavior approaches the ideal plug flow. This reactor is superior for catalytic cracking reactions in which the intermediate is the desired product. However, the hydrodynamic behavior and reactor performance have mostly been investigated in small-scale or laboratory-scale reactors. The objective of this study was to investigate the up-scaling of the catalytic cracking of heavy oil in three downer reactors with heights of 5, 15, and 30 m, using computational fluid dynamics simulations. A two-fluid model with the kinetic theory of granular flow was used to predict the hydrodynamics and performance of the chemical reactions. The kinetics of catalytic cracking of heavy oil were described by a 4-lump kinetic model. The chemical performance similarity was identified by using radial and axial distributions of heavy oil conversion, gasoline mass fraction, and gasoline selectivity. The chemical performance similarity cannot be achieved by using the hydrodynamic similarity parameter . A modified up-scaling parameter was proposed, . The chemical performance similarity of identical catalytic cracking downer reactors can be achieved with deviation in the range of ±10% and mean relative absolute error of less than 5%. |
| Databáze: | OpenAIRE |
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