Abstract
The transition toward sustainable energy systems has increased interest in hydrogen as a clean energy carrier. This study presents the design, fabrication, and evaluation of a single-cell zero-gap alkaline water electrolyser for hydrogen production and subsequent electricity generation through a fuel cell. The developed electrolyser utilised a 30 wt.% potassium hydroxide (KOH) electrolyte, nickel electrodes, and selected polymer-based structural materials evaluated for mechanical strength, corrosion resistance, and electrical suitability. Material selection was conducted using engineering property analysis, while thermal and mechanical stability of the electrolyser components were assessed through numerical simulations. The system operated at temperatures around 50°C, atmospheric pressure conditions, and applied voltages below 3.0V. Hydrogen and oxygen were generated through alkaline electrolysis and separated using a porous membrane. Experimental evaluation showed that polytetrafluoroethylene (PTFE) provided improved durability compared with polypropylene for endplates and spacers, while polypropylene nonwoven geotextile demonstrated effective membrane performance at reduced cost. The optimised operating condition occurred at 2.2 V and 1.30 A, producing approximately 14 ml/min of hydrogen. The electrolyser achieved an electrolysis efficiency of 55.6%, an energy efficiency of 67.3%, and a hydrogen production efficiency of 75.4%. The produced hydrogen and oxygen were successfully converted into electrical energy using a reversible fuel cell with a proton exchange membrane, demonstrating the feasibility of integrating alkaline electrolysis with fuel cell technology for small-scale renewable energy applications.
Keywords: alkaline electrolysis; hydrogen production; water electrolyser; fuel cell; renewable energy; hydrogen energy system.