A zero-gap spinning disc membrane electrochemical reactor (SDMER) is presented for the intensification of the chlor-alkali process at high current densities up to 20 kA/m(2). Two configurations of the SDMER, namely rotor-stator (RS) and thin-film (TF), are investigated and compared with a conventional parallel plate (PP) cell. The cell voltage as a function of current density is virtually identical for both SDMER configurations, and lower when compared to PP cell. The effect of the rotational speed on the cell voltage shows a decrease of 0.9 Vat 6 kA/m(2) when the rotational speed is increased from 40 to 60 rad/s. The estimated membrane permselectivity, increases with increasing current density to values between 0.95 and 0.98. The intensification of the chlor-alkali process was successful with the SDMER by obtaining an approximately three times higher production compared to the PP cell when increasing the current density from 6 kA/m(2) to 20 kA/m(2). (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.