Effect of nickel deposition on hydrogen permeation behavior of mesoporous gamma-alumina composite membranes.
Ni/alumina composite membranes were prepared and investigated for hydrogen separation at high temperature. alpha-Alumina-supported gamma-alumina composite membranes were prepared by soaking-rolling method. In order to improve H2 selectivity and permeance of the gamma-alumina membranes, Ni was deposited by a soaking process. As a result of a single gas permeation test of the Ni/alumina composite membranes, hydrogen permeance and H2/N2 selectivity at permeation temperature of 450 degrees C were 6.29 x 10(-7) mol/m2 s Pa and 5.2 which exceeded theoretical Knudsen selectivity. Contribution of surface diffusion was investigated by temperature dependence of H(2) permeance. The surface diffusion was observed at higher temperature above 250 degrees C. The Ni deposition on surface of the gamma-alumina composite membrane led to hydrogen permeation via Knudsen diffusion combined with surface diffusion, which gave high H2 selectivity exceeding the Knudsen diffusion mechanism.
Yu
Chang-Yeol
CY
National Research Laboratory for Functional Membranes, Environment and Energy Research Center, Korea Research Institute of Chemical Technology, PO Box 107, Yuseong, Daejeon 305-600, South Korea.
Sea
Bong-Kuk
BK
Lee
Dong-Wook
DW
Park
Sang-Jun
SJ
Lee
Kwan-Young
KY
Lee
Kew-Ho
KH