Combined hydrogen production and power generation from aluminum combustion with water: analysis of the concept

In this paper the combined production of hydrogen and power based on the aluminum combustion with water is investigated. Furthermore, a concept system is proposed that is potentially able to provide pressurized hydrogen and high temperature steam along with heat and work at the crankshaft. The system demonstrates high energy conversion efficiency, and it fully complies with environment sustainability requirements. The use of aluminum as an energy carrier or a fuel has been already studied in literature, but its application in the field of the energy conversion systems is currently not well explored. Once aluminum oxide layer is removed, the pure aluminum can react with water producing alumina and hydrogen while releasing a significant amount of heat that can be used to produce superheated steam. Both pressurized hydrogen and superheated steam can be used in a turbine power system developing electrical or mechanical power. Moreover, the hydrogen can be either stored for further usage or burned in order to obtaina larger amount of heat for the process. From an environmental viewpoint, an energy conversion system utilizing the combustionof aluminum with water is very interesting since the aluminum oxidation is completely greenhouse gases free and produces only hydrogen and alumina. The high grade alumina obtained by the reaction is harmless and can be employed in other technological processes or recycled back to aluminum; in this case, the closed loop use of aluminum would decrease significantly the need of new bauxite feedstock. Finally, an embodiment of the concept system for the combined production of hydrogen and power based on the aluminum combustion with water is proposed and its possible applications are discussed.