Automatic high-pressure H2 generation up to 40 MPa through HCO3−/CO32− enhanced Al–H2O reaction

For the practical application, storage, and transportation of hydrogen energy, compressed high-pressure H2 is generally required, which consumes large amounts of energy. In this research, an automatic high-pressure H2 production system based on the HCO3− enhanced Al–H2O reaction is established, in which, over 40 MPa H2 at 300 °C (25 MPa at 25 °C) is successfully obtained without using any compressing facilities. Energy balance calculation reveals that although this reaction requires a high temperature, it is highly exothermic (145.9 MJ/kg H2). Since heating the reactants to the desired reaction temperature only needs an energy of 55.3 MJ/kg H2, the energy requirement of this reaction can be self-supported. In addition, waste Al-can is further tested for the high-pressure H2 generation to realize a waste material recovery simultaneously, and over 40 MPa H2 at 300 °C can also be obtained with the addition of Na2CO3. This research proposes a new way of automatic high-pressure H2 production from renewable resources, which can promote the practical large-scale hydrogen energy utilization.