Solar Thermochemical Water-Splitting Reaction Enhanced by Hydrogen Permeation Membrane

The low conversion rate and efficiency always weaken the performance of thermochemical water-splitting reaction. Herein, we, for the first time, conducted the thermodynamic study of a hydrogen permeable membrane (HPM) in an isothermal thermochemical water-splitting reaction driven by solar energy, which has showed a sharply enhanced conversion rate of 87.8% at 1500 oC and 10-5 atm at permeated side (versus 1.26% with oxygen permeation membrane). According to thermodynamic analysis, the first-law thermodynamic efficiency can reach as high as 59.1%. When taking solar-to-electric efficiency and vacuum pump efficiency into account (for converting separation work into solar energy), we simulated the appreciable efficiency of 3.05% at 1500 oC. The numerical model will provide guidance for the actual production of hydrogen by high temperature solar water splitting. Such novel work manifests the great significance of constructing a HPM reactor for efficient solar thermochemical water splitting, which shows a novel approach for high-temperature solar water splitting.
Comment: 26 pages, 10 figures