An electrolysis cell for hydrogen gas production was constructed in the form of a fixed bed. The electrodes were made from 316L stainless steel in the form of cylinders 15 mm in height and diameter (aspect ratio = 1). The electrodes were immersed in an aqueous solution of 1 M, 1.5 M, and 2 M sodium hydroxide. Both anodic and cathodic solutions were pumped from a 30-liters stainless steel storage tank by two plastic pumps. Flowrate was varied during the experiments between 1,2, and 3 liters/min. The cathodic and anodic compartments were separated by a cation exchange membrane (Fumasep E-620-K). The membrane is characterized by a non-reinforced, small thickness of 20µm, with very low resistance, high selectivity, and high stability in different pH environments. Using cylindrical electrodes allowed to maximize of the surface area on each side of the cell with the same NaOH concentration. The effect of current density was investigated by conducting experiments at, 4 mA/cm2, 6 mA/cm2, and 8 mA/cm2. The temperature was also varied (55 oC, 65 oC, and 75 oC) which resulted in an increase in the cell efficiency from 8.3% to 81.5%.

The present study investigates the effect of different variables on cell performance. The different variables investigated included: solution concentration, current density, solution flow rate, and temperature. The resulting flow rate of produced hydrogen gas, the effect of electrolyte solution volume, and cell voltage were evaluated. The produced oxygen gas, power consumption, energy consumption, and ampere hour capacity are calculated, and the cell efficiency is therefore evaluated by comparing the theoretical and experimental mass flow rates of hydrogen gas. Additionally, the characterization of electrodes before and after the experiment was done using scanning electron microscopy (SEM) examination and alloy composition elemental Mapping.