Development of a silica membrane for H production from HI decomposition in the IS process

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

no journal, , 

In this study, we have developed a highly hydrogen permeable silica membrane derived from hexyltrimethoxysilane as a Si precursor using porous alumina support. Modification of alumina support tubes in the absence of and in the presence of -alumina coating was carried out by a counter diffusion chemical vapor deposition (CVD). A membrane with intermediate -alumina layer showed higher H permeance (7.7 10 mol m s Pa) than that formed directly on the -alumina tube (3.8 10 mol m s Pa). It was found that the thickness of -alumina layer played an important role in the improvement of membrane permeation performance. Modified membrane based on -alumina coating with a thickness of 1.5 m exhibited H/SF selectivity over 3000 at 270C, while maintaining H permeance in the order of 10 mol m s Pa. The results led to the conclusion that the modified membrane is a promising candidate for further enhancement of HI decomposition in membrane reactor.