Steam stability of a silica membrane prepared by counterdiffusion chemical vapor deposition Presented at the International Congress on Membranes and Membrane Processes (ICOM), Seoul, Korea, 21-26 August 2005

• Published in: Desalination 2006-01, Vol.193 (1-3), p.1-7
• Main Authors: Nomura, Mikihiro, Aida, Hitoshi, Gopalakrishnan, Suraj, Sugawara, Takashi, Nakao, Shin-Ichi, Yamazaki, Satoshi, Inada, Takeshi, Iwamoto, Yuji
• Format: Article
• Language: English
• ISSN: 0011-9164
• DOI: 10.1016/j.desal.2005.08.019

A silica membrane having an excellent H sub(2)/N sub(2) permeance ratio (over 800) was prepared by the counter-diffusion chemical vapor deposition method. The H sub(2)/N sub(2) permeance ratio was kept for 82 h under 76 kPa of steam at 773 K. The H sub(2)/H sub(2)O permeance ratio through the silica membrane was ca. 300 at 773 K. This is much higher than that through silica membranes prepared by a sol- gel method. The deposited silica layer was found in the gamma -alumina layer of the substrate by TEM observations, indicating that the silica deposition is controlled by counter-diffusion of the precursors. Steam stability tests for porous gamma -alumina substrates are also discussed. Pore size of the gamma - alumina layer increased with an increasing steam treatment period at 773 K. The pore size of the gamma -alumina layer was ca. 9 nm after 52 h of steam treatment.