Effect of KCl and soy protein concentrations on the performance of bipolar membrane electroacidification

The purpose of this study was to evaluate the effects of various combinations of initial concentrations of soy protein concentrate (SPC) (15, 30, and 60 g/L) and KCl (0.06, 0.12, and 0.24 M) on the efficiency of electroacidification technology. This procedure is derived from electrodialysis. Bipolar membrane electroacidification (BMEA) is based on the production of protons by dissociation of water molecules at the interface of membranes called bipolar membranes. The protons generated by this dissociation are able to migrate toward the cathode and acidify a protein solution. At the end of the process at pH 4.5, BMEA yields a protein precipitation of about 93% of total protein in the electroacidified solution. The SPC concentration is the primary factor in the adjustment of the system to optimum energy efficiency, by its intrinsic potassium content. Added salt affects the performance only at low SPC concentration. Increasing the SPC concentration from 15 to 60g/L and the KCI concentration from 0.06 to 0.24 M decreases the relative energy consumption from 2.82 to 0.49 kW/kg of isolate produced.