Mass transfer characteristics of a flow-by fixed bed electrochemical reactor composed of vertical stack stainless steel screens cathode

Abstract

Mass transport properties of a flow-by fixed bed electrochemical reactor composed of a vertical stack of stainless steel nets operated at a batch-recycle mode were characterized using cathodic deposition of copper as a test reaction. The electrochemical reactor was operated at constant potential in which reduction of copper happened under mass transport control. This potential was selected from the application of hydrodynamic voltammetry using a borate/chloride solution as supporting electrolyte on stainless steel rotating disc electrode. A linear relationship was observed between the flow rate and the mass transfer coefficient. The electrochemical reactor was efficient in removing copper and able to reduce the levels of this metal to lower than 0.4 ppm starting from an initial concentration of 49.7 ppm at 80 min using a ratio of cathode volume/catholyte volume equal to 0.0075. A mathematical correlation between the Sherwood number and Reynolds number were obtained which characterized the mass transport properties of the reactor as follows: Sh = 0.2254Re0.4228Sc1/3.