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Artikel
Modelling the mass transport and two-phase flow in a gas-evolving electrochemical cell.
| Författare: |
Wedin, R. |
| Dokumenttyp: |
Artikel |
| Tillstånd: |
Inskickad |
| Tidskrift: |
Journal of the Electrochemical Society |
| Volym: |
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| År: |
2001 |
AbstractVertical electrolyte channels bounded by gas-evolving electrodes are often encountered in industrial electrochemical reactors. This typical geometry is here studied from a combined hydrodynamical and electrochemical point of view. Our test system consists of a vertical channel of dimensions (1x27 cm) with alkaline electrolyte entering from below under forced convection. Hydrogen gas is evolved at the cathode and oxygen gas at the anode. By using a hydrodynamic two-phase mixture model directly coupled to electrochemical mass-transport relations, including Tafel boundary conditions, wehave modelled the distribution of velocity, void fraction, current density and electric potential. The relative motion of the two phases is modelled by introducing available empirical relations for particle transport. It is demonstrated that the presence of gas inside the channel induces a strong deformation of the velocity profile. Special attention is devoted to discussing strong peaks of electric current that appears at the edges of the electrodes. The computed tertiary current distributon along the electrodes is compared to experimental data with qualitatively good agreement.
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