Fabrication, permeation, and corrosion stability measurements of silica membranes for HI decomposition in the thermochemical iodine–sulfur process

In this study, a corrosion-stable silica membrane was developed to be used in H2 purification during the hydrogen iodide decomposition (2HI → + I2), which is new application of membranes. From practical perspective, separation length enlarged up 400 mm and one end tubes closed avoid any thermal variation along sealing issues. The membranes consisted three-layer structure comprising porous α-Al2O3 ceramic support, an intermediate layer, top layer. layer composed γ-Al2O3 or silica, that selective prepared via counter-diffusion chemical vapor deposition hexyltrimethoxysilane. To best our knowledge, first report 400-mm-long closed-end supported on Si-formed produced method. A using tube exhibited higher H2/SF6 selectivity 1240 but lower permeance 1.4 × 10−7 mol Pa−1 m−2 s−1 with compared γ-Al2O3-formed (907 5.6 s−1, respectively). more stable corrosive HI gas than after 300 h stability tests. conclusion, seem suitable for reactors produce large scale thermochemical iodine–sulfur process.