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The characteristics of a divided, industrial scale electrochemical reactor with five bipolar electrodes (each having a projected area of 0.72 m 2 ) were examined in terms of mass transport, pressure drop and flow dispersion. Global mass transport data were obtained by monitoring the (first order) concentration decay of dissolved bromine (which was generated in situ by constant current electrolysis of a 1 mol dm −3 NaBr (aq) ). The global mass transport properties have been compared with those reported in the literature for other electrochemical reactors. The pressure drop over the reactor was calculated as a function of the mean electrolyte flow velocity and flow dispersion experiments showed the existence of slow and fast phases, two-phase flow being observed at lower velocities.

Flow dispersion, pressure drop, and averaged mass transport measurements have been made to characterize the reaction environment in an industrial scale electrochemical reactor. The 10 cell filter-press stack was operated with a relatively low mean linear velocity in the range 0.6 to 6.2 cm s–1. Flow dispersion was studied by a perturbation–response technique by electrolyte conductivity measurements at the reactor outlet. Mass transport coefficients were evaluated from the first order reaction decay of dissolved bromine (Br3–) which was anodically generated from 1 mol dm–3 NaBr (aq). Each cell consisted of two 0.72 m2 projected area electrodes separated by a cationic membrane, and each electrolyte compartment contained a high-density polyolefin turbulence promoter. The electrodes consisted of a carbon/polyethylene core with a layer of an activated carbon–poly(vinylidene difluoride) composite on each side. Comparison is made with the mass transport characteristics of a similar system that contains five bipolar cells.

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