Optimization of the working cycle for a hydrogen production and power generation plant based on aluminum combustion with water

The working cycle of a novel hydrogen and power generation system based on aluminum combustion with water is analyzed in order to evaluate the best performance in terms of energy conversion efficiency. The system exploits the exothermic reaction between aluminum and steam and produces thermal power for a super-heated steam cycle and hydrogen as a by-product of the reaction. A lumped and distributed parameter approach is adopted for simulating the whole thermo-dynamics cycle and it includes the main components such as the combustion chamber, the steam generator, the turbine and the heat exchangers. Proper numerical models are created to account for the physical phenomena occurring in each of the considered component and are validated against experimental measurements available in literature or theoretical formulations. In particular several plant configurations corresponding to different working cycles are investigated, and their performance in terms of global efficiency, power output and hydrogen yield is discussed. The adoption of a turbine back pressure working cycle demonstrates to reduce the aluminum consumption and to enhance the electrical power conversion efficiency.