The polymerization of dibenzo-18-crown-6 has been carried out in an electrochemical reactor containing a granular electrode percolated by a pulsed solution. The influence of different parameters (pulse frequency, permanent flow velocity of the electrolytic solution, particle diameter and bed height) on the mass transfer has been studied. A correlation between the reduced mass transfer coefficient and the Strouhal number has been established. The maximum mass transfer coefficient and the maximum Strouhal number have been determined as a function of the Galilee number. The correlation predicts well the mass transfer coefficient over a larger range of the variables than previously achieved.