Analysis of the effects of the external conditions on the hydrogen production by a mid-scale laboratory PEM electrolyzer

The aim of the work is to study the effects that external temperature causes on hydrogen production in a mid-scale laboratory PEM Electrolyzer. Specifically, various tests were carried out, which were identical to each other except for a variation in the external temperature, simulated in the laboratory using a dynamic climate chamber. After devising, testing and fine-tuning the experimental setup, the collected data were analysed from two points of view: i) the factors that, through a change in temperature, influence the efficiency of the electrolyser and ii) the qualitative analysis of the produced gas. In particular, as temperature is considered the primary parameter assumed to exert the most significant influence on cell degradation, and given a worn cell, it was anticipated that there would be a more frequent occurrence of gas crossover phenomena through the membrane. Consequently, an alteration in the quality of the generated gas was expected to be observed. Test results indicate that the impact of external conditions cannot be disregarded in the cell’s energy consumption and deterioration processes. Nevertheless, no substantial evidence of notably significant pollutants was found in the generated hydrogen, nor were there any substantial alterations in gas quality observed. As the operating temperature varied, the sole noticeable change was an increase in the amount of water carried by the gas. Importantly, water is not properly a pollutant and can be more or less treated in subsequent drying processes, depending on the intended future utilization of the hydrogen. Finally, the discussion concluded with some considerations on the optimisation of certain setup components and the effectiveness of the start-up method used.