| With the development of separation technology,there is growing concern about hydrogen purification.This issue proposed high aspect ratio graphene oxide membranes supported on ceramic hollow fibers to improve the strength and separation performance of membrane.For this purpose,the high strength YSZ?8wt.% Y2O3 doped ZrO2?porous ceramic hollow fiber membrane was prepared by phase-inversion route and then vacuum-sucking impregnation was applied to assemble the GO laminates on the fiber external surface in the thickness of 230 nm.The 2D nano-channels formed by the two neighboring one-atom-thick GO layers endow the membrane with molecular-sieving function.Gas permeation behavior was investigated by the measurement of gas permeances from single gas component and the gas mixture from H2/N2.The ideal selectivity of H2/N2 at 20 ? was up to 76,H2 ideal permeance reached 4.4×10-8 mol·m-2·s-1·Pa-1,and N2 for 5.8×10-10 mol·m-2·s-1·Pa-1,mirroring the molecularsieving function via molecular size limited diffusion and preferable adsorption.Compared to the ideal selectivity,the H2/N2 separation factor is lower due to the blocking effect of the other component.At higher temperature,N2 permeance has been increased by a percentage more than that of H2 thus decreasing the separation factor from 68?20??to 37?100??.The H2 separation test for 240 hours highlights stable performance in maintaining the separation factor and the permeance.H2 permeation using GO/YSZ hollow fiber was also theoretically probed.Simulation implies that in achieving the overall H2 permeance,the front part?near the inlet?of the hollow fiber makes much more contribution than the rear part.To more effectively use the GO hollow fiber,feed gas pressure should be increased or application of the vacuum in the permeate side can be considered.For the sake of reducing cost and increasing bonding force between substrate and GOmembrane,this issue selected Al2O3 as substrate and prepared GO/Si-Al2O3 composite membrane?graphene oxide membranes supported on Si doped Al2O3 ceramic hollow fiber?,and then studied gas separation performance of GO/Si-Al2O3 composite membrane.Experimental results show that GO/Si-Al2O3 composite membrane also has excellent gas selective permeability,the overall law is similar to the GO/YSZ composite membrane.for the GO/2wt.%Si-Al2O3 composite membrane,the ideal selectivity of H2/ N2 was up to 50,H2 ideal permeance reached 1.2×10-7 mol·m-2·s-1·Pa-1,and N2 for 2.4×10-8 mol·m-2·s-1·Pa-1,The H2 separation test for 240 hours in the separation factor and the permeance highlights stable performance without membrane deterioration,sufficiently exhibited the industrialization prospect of GO/Si-Al2O3 composite membrane. |
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