Azeotropic distillation of hydrochloric acid in the copper-chlorine cycle for hydrogen production

In this paper, azeotropic distillation is investigated for concentrating HCl
_(aq)
between the electrolysis and hydrolysis processes of the copper-chlorine cycle for hydrogen production. Recent progress on the cycle suggests HCl
_(aq)
will need to be concentrated through its azeotrope, which cannot be achieved with typical distillation techniques. A heated distillation system is designed and constructed to investigate the distillation process on both sides of the azeotrope to collect new data for azeotropic distillation of HCl
_(aq)
. The distillation system consists of one packed distillation column with heating tapes and thermocouples to achieve a desired axial temperature profile. The column can be operated in batch or continuous mode. The HCl concentrations of the output products are determined by measuring the concentration of Cl
^-
_(aq)
ions.