(375ab) A Systematic Assessment of Carbon-Free Hydrogen Production through Vanadium-Chlorine Thermochemical Cycles

The vanadium-chlorine family of thermochemical cycles shows promise for economically viable, carbon-free hydrogen production. In this work, the potential of V-Cl cycles is investigated with our systems engineering-based approach for alternative thermochemical cycle evaluation. The five major components of the methodology are (i) conceptualization, (ii) reaction cluster synthesis, (iii) flowsheet design, simulation, and analysis, (iv) process integration and (v) performance evaluation. Using an integer linear program, multiple cycles are generated from species consisting of V, Cl, H, and O atoms and a corresponding non-linear thermodynamic database. Simulation software and heat pinch analysis are then used to systematically asses the identified reaction clusters. Initial results show V-Cl cycles with base efficiencies that exceed 50%, significantly better than the 30% efficiency of a combined Rankine cycle - water electrolysis process.