ТЕРМОХІМІЧНІ ЕФЕКТИ ПРИ ОДЕРЖАННІ ВОДНЮ В СИСТЕМІ З РОЗЧИННИМ АЛЮМІНІЄВИМ АНОДОМ

This study presents the results of experimental determination and theoretical calculations of the thermal effect of aluminum dissolution in alkaline solutions accompanied by hydrogen evolution. The experiments were conducted using an EK1 calorimeter, with temperature measurements recorded every 10 seconds. Potassium hydroxide solutions with concentrations ranging from 0.5 to 5 mol/L were utilized. It was demonstrated that the temperature variation curves over time, the temperature dynamics at different solution concentrations, and the aluminum dissolution rate exhibit an S-shaped profile. The rate of aluminum dissolution in aqueous alkaline solutions depends on the KOH concentration. As the KOH concentration increases from 0.5 to 2 mol/L, the thermal effect of the reaction rises. Further increasing the alkali concentration to 5 mol/L results in almost no change in the thermal effect. The thermal effect of aluminum dissolution in 3-5 mol/L sodium hydroxide solutions was found to be 1300 J/g. The experimentally determined thermal effect falls within the range of values calculated from thermodynamic data (from 1165 to 1528 J/g). The results obtained in this study can be applied to the development of relatively low-cost hydrogen production technologies. [ABSTRACT FROM AUTHOR]