Demonstration of the HI decomposition section embedded with electrodialysis stack in the sulfur–iodine thermochemical cycle for hydrogen production

A detection method for HIx composition in thermochemical water splitting iodine–sulfur cycle

“…(9) and (10). Using this equation set, we could calculate C HI and C I2 of a certain HIx solution by inputting its density and E value (C H2O could be worked out by mass balance).…”

“…(9) and(10) could reproduce most of the experimental values with the deviation of 5%. In addition, no accuracy difference Comparisons of calculated and experimental values of HI and I 2 molarities.…”

Experimental Study for HIx Concentration by Electro-Electrodialysis (EED) Cells in the Water Splitting Sulfur-Iodine Thermochemical Cycle

“…With this aim, an experimental campaign was carried out to obtain sensible data about this process, in order to show advantages and limitations of this technique, and to provide values for the EED process parameters, that is to say, the proton transport numbers and the osmosis coefficients, calculated at several voltages and temperatures. In particular, with respect to present literature, new types of electrodes were employed, which provide a similar efficiency of the ones previously proposed, made of glassy carbon [7][8][9][10][11][12], but do not present the problems related to iodine contamination [15].…”

“…ED-64-002 (PCA Polymerchemie Altmeier Gmbh, Germany), whose original electrodes were replaced with home-made rhodium coated titanium electrodes. Regarding the electrode materials, the scientific literature shows that glassy carbon is catalytically active for the oxidation-reduction of the I 2 /I − pair [7][8][9][10][11][12], and therefore more efficient than platinum, as reported in Figure 2.…”

“…Alternatively, a reactive distillation configuration under pressurized conditions was also investigated [4][5][6]. More recently, the use of electro-electrodialysis [7][8][9][10][11][12], pervaporation processes with cation exchange membranes [13,14] and membrane distillation [15] was proposed to concentrate HI aqueous solutions. In all cases, iodine and water excess are removed from the main stream and recycled to the Bunsen reactor.…”