Maximization of Operating Pressure and Activation Overpotential on Green Hydrogen Gas Purity of Alkaline Water Electrolysis Plants Simulated

Abstract

The production of green hydrogen through the alkaline water electrolysis (AWE) can generate a sustainable source of energy and decarbonization solution that will be further improved by the use of renewable energy sources. The paper tends to investigate the way the operating factors (pressure, temperature and concentration of electrolytes (KOH and NaOH) Besides the applied current and voltage effect on the hydrogen production in addition to energy consumption and purity of produced gas. Experiments were conducted in the laboratory with a custom electrolysis cell that held stainless steel electrodes and a variety of concentrations of KOH and NaOH to demonstrate that the KOH provides better results to the NaOH because of the greater currents (up to 6 A) and voltages (up to 40 V) produced which lead to larger amounts of H2 (1 It was found that the optimum performance is achieved in a system at high temperatures of feed 90°C and medium pressure of approximately 12 bar where KOH concentrations of 20-25 wt% increase optimal system performance. Systems based on KOH had a maximum electrolyser efficiency of about 65 percent and the reference system had a maximum electrolyser efficiency of about 60 % and a power consumption of about 39.5 kW per kilogram of H2 generated. The results of the research which we reference point towards the fact that AWE design will be simplified in such a way that it could produce the production system which would be operational at the low levels of carbon emissions and generate the hydrogen which could be utilized in the petrochemical and renewable energy activity.