Development of Silica-Zirconia Membrane for Hydrogen Separation at High Temperature and Effect of Zirconia Content on Hydrogen Permeation

摘要

Sol-gel derived silica membranes have shown large selective permeance for hydrogen at high temperature, but the stability in hydrothermal conditions is insufficient. It is considered necessary to improve their stability against hydrothermal conditions such as the LNG reforming process, which contain high concentrations of water vapor. In this work the effects of zirconium contents in silica-zirconia composite membranes on the hydrogen permeation performance were studied. A silica-zirconia membrane with molar than 100. An increase in zirconia content causes a decrease in the H_2 permeance and the permeability ratio of H_2/N_2. The activation energy of H_2 and He permeation increase with an increase in zirconia content, suggesting membrane densification with an increase in zirconia content.