Modelling and simulation of H2-H2O bubbly flow through a stack of three cells in a pre-pilot filter press electrocoagulation reactor
Modelling and simulation of H2-H2O bubbly flow through a stack of three cells in a pre-pilot filter press electrocoagulation reactor
Computational fluid dynamics simulations were carried out to describe the hydrodynamic characteristics of a two-phase bubbly flow in a filter-press flow reactor stack of three cells, which is typically used in electrocoagulation (EC). The hydrogen evolution reaction (HER) took place at the cathode; dissolution of aluminium occurred at the anode. The fundamental transport equations of momentum and electrical potential were simultaneously solved to simulate the H
2-H
2O flow. Continuous (H
2O) and dispersed phase (H
2) velocity fields were modelled via the Euler-Eulerian approach, using the biphasic Reynolds Averaged Navier-Stokes (RANS) equations and the standard k − ε turbulence model. The influence of volumetric flow rate (1.7 ≤ Q ≤ 15 cm
3 s
−1) and applied current density (–28 ≤ j ≤ –5 mA cm
−2) was systematically addressed to calculate the fraction of dispersed phase and current distribution along the electrodes. The evolved H
2 bubbles were transported away from the electrode by the liquid flow. The dispersion of H
2 through the electrode gap showed a modest bubble curtain profile due to the liquid flow rate. A homogeneous current distribution along the electrode length was experienced due to the geometrical design of the electrochemical cell and the low degree of H
2 dispersion. The velocity profiles of the H
2-H
2O mixture were different in each cell due to the change of flow direction. H
2 bubbles increased the velocity of the liquid phase but the gas fraction of such bubbles resulted in a higher pressure drop. Good agreement between theoretical and experimental residence time distribution curves was achieved; the experimental aluminium dose released by the anode agreed well with the simulations.
biphasic turbulent flow, current distribution, euler-eulerian approach, hydrogen evolution reaction, multi-electrode stack
Sandoval, Miguel A.
ee1d580e-9443-4370-b2bf-e71da72cf1ef
Fuentes, Rosalba
eb7b9157-273e-42ce-999c-2996ef3cf6f3
Pérez, Tzayam
7c1c644e-d97d-4a4f-9384-0803b62a2d73
Walsh, Frank
309528e7-062e-439b-af40-9309bc91efb2
Nava, Jose L.
266d748b-426f-4300-9306-0a2fe549bd15
Ponce De Leon Albarran, Carlos
508a312e-75ff-4bcb-9151-dacc424d755c
15 April 2021
Sandoval, Miguel A.
ee1d580e-9443-4370-b2bf-e71da72cf1ef
Fuentes, Rosalba
eb7b9157-273e-42ce-999c-2996ef3cf6f3
Pérez, Tzayam
7c1c644e-d97d-4a4f-9384-0803b62a2d73
Walsh, Frank
309528e7-062e-439b-af40-9309bc91efb2
Nava, Jose L.
266d748b-426f-4300-9306-0a2fe549bd15
Ponce De Leon Albarran, Carlos
508a312e-75ff-4bcb-9151-dacc424d755c
Sandoval, Miguel A., Fuentes, Rosalba, Pérez, Tzayam, Walsh, Frank, Nava, Jose L. and Ponce De Leon Albarran, Carlos
(2021)
Modelling and simulation of H2-H2O bubbly flow through a stack of three cells in a pre-pilot filter press electrocoagulation reactor.
Separation and Purification Technology, 261, [118235].
(doi:10.1016/j.seppur.2020.118235).
Abstract
Computational fluid dynamics simulations were carried out to describe the hydrodynamic characteristics of a two-phase bubbly flow in a filter-press flow reactor stack of three cells, which is typically used in electrocoagulation (EC). The hydrogen evolution reaction (HER) took place at the cathode; dissolution of aluminium occurred at the anode. The fundamental transport equations of momentum and electrical potential were simultaneously solved to simulate the H
2-H
2O flow. Continuous (H
2O) and dispersed phase (H
2) velocity fields were modelled via the Euler-Eulerian approach, using the biphasic Reynolds Averaged Navier-Stokes (RANS) equations and the standard k − ε turbulence model. The influence of volumetric flow rate (1.7 ≤ Q ≤ 15 cm
3 s
−1) and applied current density (–28 ≤ j ≤ –5 mA cm
−2) was systematically addressed to calculate the fraction of dispersed phase and current distribution along the electrodes. The evolved H
2 bubbles were transported away from the electrode by the liquid flow. The dispersion of H
2 through the electrode gap showed a modest bubble curtain profile due to the liquid flow rate. A homogeneous current distribution along the electrode length was experienced due to the geometrical design of the electrochemical cell and the low degree of H
2 dispersion. The velocity profiles of the H
2-H
2O mixture were different in each cell due to the change of flow direction. H
2 bubbles increased the velocity of the liquid phase but the gas fraction of such bubbles resulted in a higher pressure drop. Good agreement between theoretical and experimental residence time distribution curves was achieved; the experimental aluminium dose released by the anode agreed well with the simulations.
Text
Revised Manuscript
- Accepted Manuscript
More information
Accepted/In Press date: 16 December 2020
e-pub ahead of print date: 25 December 2020
Published date: 15 April 2021
Additional Information:
Funding Information:
Miguel A. Sandoval is grateful to CONACYT (Mexico) for granting the postdoctoral scholarship, No. 386022. J.L. Nava acknowledges Universidad de Guanajuato (Mexico) for financial support through the project No. CIIC 113/2020.
Publisher Copyright:
© 2020 Elsevier B.V.
Keywords:
biphasic turbulent flow, current distribution, euler-eulerian approach, hydrogen evolution reaction, multi-electrode stack
Identifiers
Local EPrints ID: 446978
URI: http://eprints.soton.ac.uk/id/eprint/446978
ISSN: 1383-5866
PURE UUID: e1638361-db44-4b19-a278-d3bf06264021
Catalogue record
Date deposited: 01 Mar 2021 17:31
Last modified: 17 Mar 2024 06:19
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Contributors
Author:
Miguel A. Sandoval
Author:
Rosalba Fuentes
Author:
Tzayam Pérez
Author:
Jose L. Nava
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