Conjugated processes of bulk aluminum and hydrogen combustion in water-oxygen mixtures

摘要

The article deals with the investigation of the combustion of aluminum bulk samples in water vapor, an aqueous solution of hydrogen peroxide (33.1 wt%), and water-oxygen mixture at uniform heating of the reactor (1 K/min) up to 773 K. It is revealed that the major portion of hydrogen peroxide is decomposed directly in aqueous solution. The resulting oxygen, as well as oxygen added to the water, provided oxidation of only a part of hydrogen (approximate to 25%) released during the complete oxidation of aluminum by water. The time dependences of the reactants' temperature and pressure, as well as the temperature corresponding to the onset of the H-2 release were determined. The most intense oxidation of aluminum in water vapor was noted within the temperature range of 593-769 K, as well as in a hydrogen peroxide solution at 548-693 K, and in H2O/O-2 mixture at 567-742 K. It is revealed that the oxidation of hydrogen with oxygen intensifies water oxidation of aluminum to a greater extent than it follows from the heat effects of H-2 oxidation. As a result of oxidation, a loose powder of aluminum oxide nanoparticles was obtained. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.