陶瓷中空纤维透氧膜集束与高温密封

发布时间：2018-02-03 18:56

本文关键词： 钙钛矿膜中空纤维集束机械强度氧渗透　出处：《天津工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：混合离子-电子陶瓷(MIEC)中空纤维透氧膜因具有能耗低、安装方便、对氧具有100%选择性等特点而受到广泛关注,但是陶瓷中空纤维膜固有的脆性以及直径小、壁厚薄而导致膜的机械强度低,并且在高温下难密封且不易组件,这些限制了它的大规模应用。本文针对这些问题展开了一系列研究,选择La0.6Sr0.4Co0.2Fe0.803-δ(LSCF)中空纤维膜作为研究对象,采用钙钛矿材料作为粘结剂将多根LSCF膜进行集束,探究该方法对膜的透氧量和机械强度的影响,并对LSCF膜束的高温密封做了一定的研究。LSCF是典型的MIEC膜材料,因此我们选择LSCF膜进行集束,为了达到更好的集束效果,本章选择了 LSCF钙钛矿材料作为粘结剂。并对LSCF中空纤维膜束进行一系列表征和氧渗透测试,实验结果表明利用具有多孔结构的钙钛矿材料对中空纤维膜集束不仅能提高膜束的机械强度而且还促进了膜束的表面交换动力学,因而提高了氧渗透速率。机械强度由单根膜的112.68MPa提高到10根膜束的150.5MPa;透氧量由单根膜的0.4mLcm-2min-1提高到10根膜束的0.61 mL cm-2min-1,其中膜束的最佳孔隙率范围在0.26-0.38之间,过低的孔隙率会对膜束的氧渗透性能造成阻力。同时中空纤维膜束在氧渗透过程中表现出很好的稳定性。LSCF材料稳定性高但透氧量偏低,而Ba0.5Sr0.5Co0.4Fe0.6O3-δ(BSCF)材料表现出很高的透氧量更有利于表面氧交换反应动力学,因此我们选择BSCF材料作为粘结剂对LSCF膜进行集束。单根膜透氧量为0.42 mL cm-2 min-1提高到10根膜束透氧量为的0.66 mL cm-2min-1,同时机械强度由单根膜的112.68 MPa提高到10根膜束的139.6 MPa。利用BSCF粉体作为粘结剂集束的中空纤维膜氧渗透通量高于LSCF粉体作为粘结剂所制备的,同时中空纤维膜束在氧渗透中也表现出很好的稳定性。通过测试各种密封胶的最高工作温度,选定HBC-1096胶作为密封材料然后与LSCF粉体按照一定的比例配制成密封剂。在对LSCF中空纤维膜束进行透氧测试前,利用所配制的密封剂对LSCF膜束进行密封,采用银浆作为陶瓷中空纤维膜束的保护层,防止LSCF膜束与所配制的密封剂发生反应,影响其机械强度和透氧性能。结果表明:当采用银浆作为4根LSCF中空膜束的密封保护层时,膜束的机械强度由原来的89.7 MPa提高到135.6 MPa。
[Abstract]:Mixed ionic electronic ceramics (MIEC) hollow fiber membrane with low energy consumption, convenient installation, the oxygen with 100% selectivity and attracted widespread attention, but the inherent brittleness of ceramic hollow fiber membrane and small diameter, wall thickness and mechanical strength of the film caused low, and at high temperature and hard sealing easy assembly, which limits its large-scale application. This paper carries out a series of research, selection of La0.6Sr0.4Co0.2Fe0.803- 8 (LSCF) hollow fiber membrane as the research object, as a binder a plurality of LSCF film by cluster perovskite materials, explore the method of oxygen permeability and mechanical strength of the membrane, and high temperature on LSCF the sealing film bundle to do the research of.LSCF is the typical MIEC film material, so we choose LSCF membrane bundle, in order to achieve better clustering effect, this chapter chooses the LSCF perovskite material The material as binder. The LSCF hollow fiber membrane beam through a series of characterization and oxygen permeation test, the experimental results show that the porous perovskite materials of hollow fiber membrane cluster can not only improve the mechanical strength of the membrane bundle but also promote the exchange of film on the surface of beam dynamics, thus increasing the oxygen permeation rate of mechanical strength. A single film increased from 112.68MPa to 10 root membrane bundle 150.5MPa; oxygen permeability increased by a single membrane 0.4mLcm-2min-1 to 10 beam 0.61 mL cm-2min-1 film, the film bundle the best porosity in the range of 0.26-0.38, the low porosity of the membrane bundle oxygen permeability by resistance. At the same time the hollow fiber membrane bundle in oxygen the penetration process showed good stability and stability of.LSCF materials but high oxygen permeability is low, and the Ba0.5Sr0.5Co0.4Fe0.6O3- Delta (BSCF) materials exhibit high oxygen permeability is more conducive to the surface The oxygen exchange reaction kinetics, so we choose BSCF as the binder material on the LSCF film. The single bundle membrane oxygen 0.42 mL cm-2 min-1 increased to 10 for the beam root membrane oxygen permeability of 0.66 mL cm-2min-1, and the mechanical strength by a single membrane of 112.68 MPa increased to 10 of the 139.6 MPa. as the root membrane bundle of hollow fiber membrane oxygen a binder permeation flux is higher than that of LSCF powder as a binder prepared by using BSCF powder, and the hollow fiber membrane bundle in oxygen permeability also showed good stability. The maximum working temperature of test sealant, selected HBC-1096 gum as the sealing material and LSCF powder according to a certain proportion of sealant in the beam of LSCF hollow fiber membrane oxygen permeability of LSCF membrane before the test beam is sealed by the sealant prepared by using silver paste as a protective layer of ceramic hollow fiber membrane bundle, prevention The LSCF membrane is reacted with the prepared sealant, affecting its mechanical strength and oxygen permeability. The results show that when the silver paste is used as the seal protection layer of 4 LSCF hollow film bundles, the mechanical strength of the membrane bundle is increased from 89.7 MPa to 135.6 MPa..

【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ051.893

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