双相离子—电子导体中空纤维膜透氧性能研究

发布时间：2018-06-08 19:08

  本文选题：中空纤维膜 + 离子-电子双相混合导体　； 参考：《山东理工大学》2017年硕士论文

【摘要】：混合导体陶瓷透氧膜因其具有100%的氧离子选择性,在纯氧制备、富氧燃烧以及甲烷与乙烯、乙烷的氧化耦合反应等领域具有良好的应用前景。但由于传统的钙钛矿型混合导体陶瓷透氧膜在CO_2和还原气氛中不稳定而限制了应用。本论文,将构建一种由50wt%Pr0.1Gd0.1Ce0.8O_2-δ-50wt%CoFe2O4(50PGCO-50CFO)组成的新型双相中空纤维膜,并用钙钛矿结构的Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF)陶瓷氧渗透材料进行修饰,研究透氧性能及稳定性能,以期提高其耐二氧化碳性能。首先,采用一锅法合成50PGCO-50CFO双相粉体,通过XRD、XPS、TEM等测试手段,发现一锅法制备的粉体均匀分布,离子导体和电子导体可形成连续的传输网络。其次,基于相转化-烧结技术制备50PGCO-50CFO致密中空纤维膜。在1000℃,使用氦作为吹扫气时,透氧速率可以达到0.54mL·min-1·cm-2;用纯CO_2在950℃吹扫时,透氧速率为0.40mL·min-1·cm-2,且连续运行200h透氧量没有明显的降低,膜也没有出现恶化现象,表现出了良好的耐二氧化碳性能。为提高透氧性,我们又通过溶胶-凝胶法制备了BSCF粉体,用以修饰双相50PGCO-50CFO中空纤维膜。用相转化-烧结技术制备的BSCF透氧膜,在1000℃,使用氦作为吹扫气时,透氧速率可以达到6.88mL·min-1·cm-2;用纯CO_2在950℃吹扫时,透氧量在前40h,透氧速率由2.72mL·min-1·cm-2降到1.79mL·min-1·cm-2。BSCF的透氧速率虽然高于PGCO-CFO双相膜,然而在CO_2气氛中极不稳定,透氧速率急剧下降,甚至为0。将高透量的BSCF混合导体涂覆在双相透氧膜的表面,明显增加了氧渗透膜的三相界面,因而在相同测试条件下,双相膜的透氧速率提高了60%。
[Abstract]:Because of its 100% oxygen ion selectivity, mixed conductor ceramic permeable membrane has a good prospect in the fields of pure oxygen preparation, oxygen-enriched combustion and the oxidative coupling reaction of methane with ethylene and ethane. However, the application of traditional perovskite-type mixed conductor ceramic oxygen permeable membrane is limited due to the instability in COST2 and reduction atmosphere. In this thesis, a novel biphasic hollow fiber membrane consisting of 50 wtPr0.1Gd0.1Ce0.8O2- 未 -50wtCoFe2O4 / 50PGCO-50CFO) was constructed and modified with perovskite Ba0.5Sr0.5Co0.8Fe0.2O3- 未 BSCF-based ceramic oxygen permeable material to study its oxygen permeability and stability, in order to improve its carbon dioxide resistance. Firstly, 50PGCO-50CFO duplex powder was synthesized by one-pot method. By means of XRDX XPS TEM, it was found that the powder prepared by one-pot method was uniformly distributed and the ionic and electronic conductors could form a continuous transmission network. Secondly, 50 PGCO-50 CFO dense hollow fiber membrane was prepared based on phase conversion-sintering technology. At 1000 鈩，

本文编号：1996881