Green Hydrogen Gas Production Using an Adapted Electrolysis Method

Abstract

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%.