All-Electric Ship On-Board Continuous Sustainable H2 Generation from Aluminum Scrap and Seawater

A mathematical model of a sustainable H2 generation reactor that utilizes aluminum and seawater is introduced. Conservation of species and the kinetics of the H2 production reaction from aluminum and seawater allowed for obtaining the process transient response in a batch reactor. Continuous steady state production was assessed by adding a balance of energy, allowing for reactants inlet mass flow rates, and calculating the outlet H2 mass flow (generation) rate. The theoretical H2 production curve data showed good quantitative and qualitative agreement with experimental data. The validated mathematical model was then used to optimize the continuous reactor. The maximum was sharp, since an 85% variation between the maximum and the smallest H2 generation rate value as a function of the inlet NaOH solution volumetric flow rate tested range was verified. Such fundamental result stresses the importance of operating the system at the optimal condition, no matter how complex the actual reactor design may be. Since aluminum is inexpensive, abundant, and fully recyclable, in situ sustainable H2 production could allow for fuel cell stacks to become all electric ships (AES) power sources.