TY - JOUR
T1 - Defect-Patching of Zeolite Membranes by Surface Modification Using Siloxane Polymers for CO2 Separation
AU - Zhou, Rongfei
AU - Wang, Huamei
AU - Wang, Bin
AU - Chen, Xiangshu
AU - Li, Shiguang
AU - Yu, Miao
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/8/5
Y1 - 2015/8/5
N2 - Grain boundary defects are normally formed in zeolite membranes during membrane preparation and calcination processes. In this work, a siloxane polymer coating with an imidazole group was grafted on the surface of defective SSZ-13 membranes by chemical liquid deposition to seal the defects. The parameters, such as silanization time, polymerization time, monomer type, and concentration, were optimized. Characterizations including Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy showed that siloxane polymers were coated on the surfaces of SSZ-13 crystals and membrane. Six modified membranes showed decreased CO2 permeance by only 21 ± 5% [average CO2 permeance of 1.9 × 10-7 mol/(m2 s Pa)] and increased CO2/CH4 selectivity by a factor of 9 ± 3 (average CO2/CH4 selectivity of 108) for an equimolar CO2/CH4 mixture at 298 K. CO2/CH4 and CO2/N2 selectivities of the modified membrane decreased with pressure and temperature. Membrane stability was investigated by a long-time test and exposures to water vapor at temperatures up to 378 K and to some organic solutions. This modification method is also effective in sealing the defects of other zeolite membranes, such as AlPO-18 membranes.
AB - Grain boundary defects are normally formed in zeolite membranes during membrane preparation and calcination processes. In this work, a siloxane polymer coating with an imidazole group was grafted on the surface of defective SSZ-13 membranes by chemical liquid deposition to seal the defects. The parameters, such as silanization time, polymerization time, monomer type, and concentration, were optimized. Characterizations including Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy showed that siloxane polymers were coated on the surfaces of SSZ-13 crystals and membrane. Six modified membranes showed decreased CO2 permeance by only 21 ± 5% [average CO2 permeance of 1.9 × 10-7 mol/(m2 s Pa)] and increased CO2/CH4 selectivity by a factor of 9 ± 3 (average CO2/CH4 selectivity of 108) for an equimolar CO2/CH4 mixture at 298 K. CO2/CH4 and CO2/N2 selectivities of the modified membrane decreased with pressure and temperature. Membrane stability was investigated by a long-time test and exposures to water vapor at temperatures up to 378 K and to some organic solutions. This modification method is also effective in sealing the defects of other zeolite membranes, such as AlPO-18 membranes.
UR - http://www.scopus.com/inward/record.url?scp=84938603226&partnerID=8YFLogxK
U2 - 10.1021/acs.iecr.5b01034
DO - 10.1021/acs.iecr.5b01034
M3 - 文章
AN - SCOPUS:84938603226
SN - 0888-5885
VL - 54
SP - 7516
EP - 7523
JO - Industrial and Engineering Chemistry Research
JF - Industrial and Engineering Chemistry Research
IS - 30
ER -