The potential drop occurring in the bed of the flow-through porous electrode (fpe) changes the local metal-solution potential difference (Ipd). Thus it may destroy the considered electrochemical reaction specificity or limit the electrolytic cell efficiency.
So, it's necessary to compute thefpe geometry (bed height, particles diameter) which satisfies the Ipd for a chosen pair Row-yield.
This study, realized in the case of a fixed bed built with very conductive particles, proposes a generalized equations system which permits the fpe design. It's possible to do the same for an undistinguished electrochemical reaction by introducing a characteristic number of this system. From these equations a design diagram is established.
A discussion about the axial field electrode limits as performing reactor follows.
NOMENCLATURE
Molecular concentration of electroactive species (Mole . m-s) Inlet molecular concentration (Mole . m-') Diffusion coefficient (m2 * s-l) Particles diameter (m) Local metal-solution potential difference. (V) Electric field vector Faraday's number = 96500 C Current density vector due to electroactive species (A .m-') Current density vector due to i species (A . m-') Current density vector in solution (A -mW2) Average mass transfer coefficient between flowing solution and electrode surface (m s-l) Height of cathodic porous bed (m)