Effect of CO2 concentration on the kinetics of the hydralloy C5

Abstract

The article discusses the effect of a high concentration of CO2 on the kinetics of the hydrogen absorption and desorption process in the metal hydride alloy Hydralloy C5, on which research is being carried out on the ability of the metal hydride (MH) alloy to separate hydrogen from unwanted synthesis gas components. The focus is on the contamination of the alloy by the carbon dioxide, which is the main gas found in the mixture of unwanted gases after SYNGAS has been modified to increase the percentage of hydrogen in the gas mixture. Carbon dioxide, as a significant oxidant, significantly affects the kinetics of the selected metal hydride alloy. With the increasing percentage representation of the given gas in the mixture with hydrogen, the rate of deterioration of the alloy’s properties increases. The process of contamination of the alloy with carbon dioxide occurs by its decomposition into carbon monoxide and oxygen and subsequent oxidation of the surface layers of the alloy grains, which prevents or significantly degrades the passage of hydrogen into the structure of the metal hydride alloy.