| In this paper, YSZ electrolyte membranes were fabricated by a phase inversion method, the factors, such as the type and concentration of polymer, the composition of core liquid and outside coagulation bath, which impact the structure and performance of hollow fibres were systematically studied. In order to achieve efficient CO2 separation at elevated temperature, electrolyte-molten salt compound hollow fibre membranes were prepared, and the structure and separation performance of the dual phase membranes were investigated.The YSZ hollow fibre membranes were obtained by phase inversion method from YSZ powders, and the effect of the type and concentration of polymer and the composition of core liquid to the membranes were studied. With the increase of the content of the PSF in the polymer, the mechanical strength and the tightness of the YSZ hollow fibre membranes were improved, the porosity and the water flux were reduced. When the content of PSF was reached 75%, the mechanical strength of the fabricated YSZ hollow fibre membranes was achieved 45.8MPa, the porosity was 48% and the water flux was reached 75 m3/(m2·h). When the NMP content in the core liquid remained unchanged, the water content was increased or the ethanol amount was decreased, the thickness of sponge-like pore layer of the YSZ hollow fibre membranes was increased while the bore amount and the bore diameter of both the inner and outer surfaces were reduced, the mechanical strength and the tightness were elevated but the porosity and water flux were dropped. When the water content in the bore liquid was 30%, the mechanical strength of the prepared YSZ hollow fibre membranes was 76.34MPa, the porosity was 58.3% and the water flux was reached 62.04 m3/(m2·h).YSZ hollow fibre membranes with different micro structure and performance were fabricated using a modified phase inversion method. The influence of core liquid flow rate and the composition of the outside gel solution to the membranes were investigated. The results revealed that the appropriate core liquid flow rate was 16mL/min. In the case that the mixture of NMP and water were used as outside gel solution, the porosity of the prepared YSZ hollow fibre membranes with a similar outer surface structure was approximately 40%-60%. When the content of ethanol and water in the outside gel solution stayed at a low level, the outer surface structure of the YSZ hollow fibre membranes obtained almost kept constant. However, in the condition that the PESf and NMP were used as outside gel solution, the outer surface structure of the prepared YSZ hollow fibre membranes was different compared with the fibre membranes mentioned previously. The finger-like pores was arranged regularly in the outer surface, and the porosity was over 60%.The YSZ-carbonate dual phase hollow fibre membrane was prepared using a combined spinning (or phase inversion), impregnation and sintering method. Some properties was investigated, such as air tightness. Designed and assemblied reactor for gas separation, and investigated the separation performance of CO2 under the different temperature. In comparison with the original pure YSZ hollow fibre, the porous structure of the infiltrated fibre was covered by the carbonate crystals, in particular viewed from the surface area. The high temperature CO2 permeation was tested within the temperature regime from 550 to 950℃.At lower temperature of 550℃, the CO2 flux was only 0.022 mL·cm-2·min-1, which had been improved by a factor of 10 to 0.22 mL·cm-2·min-1 for the operation at 950℃. The CO2 permeation of flat inorganic membranes is obviously lower than hollow ceramic membrane. |
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