TY - JOUR
T1 - Synthesis and modification of ZSM-5/silicalite bilayer membrane with improved hydrogen separation performance
AU - Wang, Haibing
AU - Lin, Y. S.
N1 - Funding Information:
The authors would like to acknowledge the support of the U.S. Department of Energy ( DE-PS36-03GO93007 ) for this project.
PY - 2012/4/1
Y1 - 2012/4/1
N2 - MFI type zeolite membrane offers good stable and high hydrogen separation performance, making it attractive for application in membrane reactors for water gas shift (WGS) reaction for hydrogen production. The hydrogen permselectivity of MFI zeolite membranes can be improved by intracrystalline pore modification. However, more than one order of magnitude reduction in H 2 permeance usually accompanies with the significant improvement in H 2/CO 2 separation factor of MFI zeolite membranes modified by catalytic cracking deposition (CCD) of methyldiethoxysilane. In this work, a thin, high quality ZSM-5 top layer was synthesized on a thick silicalite bottom layer to form a ZSM-5/silicalite bilayer membrane. The ZSM-5/silicalite bilayer zeolite membrane was supported on a porous α-alumina support coated with an yttria stabilized zirconia (YSZ) intermediate barrier layer for membrane stability improvement. The CCD modification of the bilayer zeolite membrane resulted in an improvement of H 2/CO 2 separation factor of the membrane by over five-fold from 4.95 to 25.3 with only about 31% reduction in H 2 permeance from 1.85×10 -7 to 1.28×10 -7molm -2sPa at 450°C. The significant improvement in H 2/CO 2 separation factor with only moderate reduction in H 2 permeance of the modified ZSM-5/silicalite bilayer membrane is due to controlled CCD modification in the thin, high quality ZSM-5 top layer instead of the entire zeolite membrane thickness. Because of the high H 2/CO 2 separation performance, considerable H 2 permeance and good hydrothermal stability under H 2S containing gas, the modified ZSM-5/silicalite bilayer membrane is very promising to be used as a membrane reactor for WGS reaction for hydrogen production.
AB - MFI type zeolite membrane offers good stable and high hydrogen separation performance, making it attractive for application in membrane reactors for water gas shift (WGS) reaction for hydrogen production. The hydrogen permselectivity of MFI zeolite membranes can be improved by intracrystalline pore modification. However, more than one order of magnitude reduction in H 2 permeance usually accompanies with the significant improvement in H 2/CO 2 separation factor of MFI zeolite membranes modified by catalytic cracking deposition (CCD) of methyldiethoxysilane. In this work, a thin, high quality ZSM-5 top layer was synthesized on a thick silicalite bottom layer to form a ZSM-5/silicalite bilayer membrane. The ZSM-5/silicalite bilayer zeolite membrane was supported on a porous α-alumina support coated with an yttria stabilized zirconia (YSZ) intermediate barrier layer for membrane stability improvement. The CCD modification of the bilayer zeolite membrane resulted in an improvement of H 2/CO 2 separation factor of the membrane by over five-fold from 4.95 to 25.3 with only about 31% reduction in H 2 permeance from 1.85×10 -7 to 1.28×10 -7molm -2sPa at 450°C. The significant improvement in H 2/CO 2 separation factor with only moderate reduction in H 2 permeance of the modified ZSM-5/silicalite bilayer membrane is due to controlled CCD modification in the thin, high quality ZSM-5 top layer instead of the entire zeolite membrane thickness. Because of the high H 2/CO 2 separation performance, considerable H 2 permeance and good hydrothermal stability under H 2S containing gas, the modified ZSM-5/silicalite bilayer membrane is very promising to be used as a membrane reactor for WGS reaction for hydrogen production.
KW - Catalytic cracking deposition
KW - MFI zeolite membrane
KW - ZSM-5/silicalite bilayer membrane
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U2 - 10.1016/j.memsci.2012.01.008
DO - 10.1016/j.memsci.2012.01.008
M3 - Article
AN - SCOPUS:84857065177
SN - 0376-7388
VL - 396
SP - 128
EP - 137
JO - Journal of Membrane Science
JF - Journal of Membrane Science
ER -