H2 production by Zn hydrolysis in a hot‐wall aerosol reactor

A novel process for hydrogen generation from water at high conversion is presented that is based on zinc hydrolysis as part of the two‐step water‐splitting thermochemical cycle of Zn/ZnO redox reactions. It encompasses formation of Zn nanoparticles by steam‐quenching a Zn(g) flow followed by in situ hydrolysis. The process is experimentally demonstrated at the laboratory scale using a tubular aerosol flow reactor featuring a Zn‐evaporation, a mixing and a reaction zone. In the reaction zone, operated at and just below the Zn(g) saturation temperature, Zn particles were formed and hydrolyzed with chemical conversion of up to 70%. The onset of H2 formation is traced to ZnO formation by surface growth along the reactor axis using X‐ray diffraction and microscopic analyses of Zn and ZnO particles collected on the reactor walls and effluents.