Application of cross-linked radiation-grafted cation exchange membranes for HI concentration

Tanaka, Nobuyuki ; Sawada, Shinichi*; Yamaki, Tetsuya*; Kodaira, Takahide*; Kimura, Takehiro*; Nomura, Mikihiro*

JAEA has been conducted R&D on thermochemical water-splitting Iodine-Sulfur (IS) process. IS process has hydrogen iodide (HI) concentration section by electro-membrane process, which is so-called the electro-electrodialysis (EED). EED is the key unit operation to improve the process efficiency. In our previous study, the cation exchange membrane (CEM) was prepared by radiation-induced grafting method, and applied to EED. Our previous study suggested that permeation of anionic species and water must be inhibited to increase H+ selectivity. In the present study, to achieve this requirement, we used the novel crosslinked grafted CEMs, which were prepared by co-grafting of crosslinked agent. The performance was also evaluated experimentally for the conventional non-crosslinked and crosslinked CEMs by carrying out HI concentration tests. In conclusion, due to the cross-linking structure, we found the improvement of concentration performance.