Dynamic response of a sono-electrolyzer under PV supply for hydrogen production: A modelling approach for the kinetic and energetic assessment under northern Algerian meteorological conditions

The experimental study of a membraneless single cell of a sono-electrolyzer based on indirect continuous sonication (40 kHz, 60 W_e) and alkaline electrolysis under a current source is being harnessed to model and simulate the performance of a multi-cell sono-electrolyzer supplied by PV under the real meteorological conditions. The study focuses on the kinetic performance in terms of hydrogen production rates, and the energetic performance through the monitoring of the efficiency of energy conversion. The site of the study (36.9° N, 7.77° E) is located at the extreme North-East of Algeria, whilst the studied period covers the semester ranging from March to September. The alkaline electrolyte consists of 25% w/w of KOH aqueous solution, and Nickel plate is considered for the electrodes’ material. A validated semi empirical model for the dynamic assessment of the global incident solar radiation is adopted, in association with a fundamental model based on the electrical analogy of the electrolytic cell. The sonication is integrated within the model throughout the electrodes’ coverage percentage affecting the bubble resistance and consequently the ohmic overpotential.

The experimental setup and measurements, coupled to the preliminary numerical model led to a fraction of electrodes’ coverage of 37%. The characterization of the sonication system through the calorimetric technique demonstrated an acoustic efficiency of 13.7%. the connection of the PV to the multi-cell sono-electrolyzer has been optimized under the average polarization curves at the selected representative days within the studied period. The gain in terms of the bubble and ohmic resistances have been deduced for the final design throughout the simulated dynamic conditions.