Modeling of dissolution phenomena in Cu-Cl Cycle for hydrogen production

Abstract

The dissolution process of cuprous chloride (CuCl) in aqueous hydrochloric acid (HCl_(aq)) is one of the crucial intermediary steps in the thermochemical water splitting cycle to produce hydrogen. A mass transfer model for dissolution process presented in this paper has been developed based on Noyes Whitney equation which is dependent on concentration gradient across the boundary layer and solute's remaining surface area. The concentration variation and remaining surface area of CuCl in 6 M and 9 M HCl_(aq) have been observed with time and mass transfer coefficient has been calculated with and without mixing during the dissolution. The mass transfer coefficient of CuCl dissolution in 6 M HCl without mixing effect has been calculated as 0,29.10⁻⁵ m/s while mass transfer coefficient of dissolution with mixing effect as 1,09.10⁻⁵ m/s. This indicates that mixing the solution can increase the mass transfer rate and reduce the dissolution time. The proposed mass transfer model has been verified with previous experimental data obtained from the literature and exhibited exceptionally good agreement. Further results obtained from the simulation study have been discussed in detail.