Preparation of an H-permselective silica membrane for the separation of H from the hydrogen iodide decomposition reaction in the iodine-sulfur process

熱化学水素製造法ISプロセスのヨウ化水素分離器に用いるシリカ製高性能水素分離膜の開発

Myagmarjav, O.  ; 池田 歩*; 田中 伸幸 ; 久保 真治  ; 野村 幹弘*

Myagmarjav, O.; Ikeda, Ayumi*; Tanaka, Nobuyuki; Kubo, Shinji; Nomura, Mikihiro*

A high performance hydrogen-permselective silica membrane derived from hexyltrimethoxysiline (HTMOS) Si-precursor was developed to enhance chemical equilibrium ratio of hydrogen iodide (HI) decomposition in thermochemical water-splitting iodine-sulfur (IS) process. The silica membrane, called the HTMOS membrane, was prepared via a counter diffusion chemical vapor deposition method. The HTMOS membrane prepared at an optimal condition of 450C within 5 min showed highest H permeance of the order of 10 mol Pa m s with a H/SF selectivity of 276. It was found that the HTMOS membrane was stable in HI exposure at 400C during 8 h and its HI permeance was the order of 10 mol Pa m s. It was demonstrated that the newly developed the HTMOS membrane could be a promising candidate for HI decomposition membrane reactor at working temperature of around 400C.