Green hydrogen from sono-electrolysis: A coupled numerical and experimental study of the ultrasound assisted membraneless electrolysis of water supplied by PV

Abstract

The present study combines experiments performed at the laboratory scale with the numerical modelling of a PV-supplied membraneless sono-electrolyzer, based on alkaline electrolysis and indirect continuous and pulsed sonications. The study aims to elucidate the effect of ultrasound on the bubble removal from electrodes’ surfaces and quantify the sonication effect through the fraction of bubble coverage. The membraneless sono-electrolyzer is experimentally designed using an H-cell and an ultrasound bath (60 W, 40 kHz), while it is modelled using the activation, ohmic and concentration overpotentials, and a mathematical model describing the performance of the ET- M53640 solar panel.The combined approach is based on the study of the effect of the electrodes’ coverage percentage on the ohmic parameters of the electrolysis cell in each case under the PV supply, and the identification of the value of the coverage percentage corresponding to the experimental configuration through the cell voltage. The PV panel has been exposed to various incident solar radiation leading to identical cell voltages of 5.957 V (± 0.1%) measured experimentally, with the three configurations. The combined approach demonstrated that the integration of indirect continuous sonication reduced the bubble resistance by 76% as compared to silent conditions, and by 52% relatively to pulsed sonication.