Partovi Kaveh, Liang Fangyi, Ravkina Olga, Caro Jürgen
Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover , Callinstraße 3A, D-30167 Hannover, Germany.
ACS Appl Mater Interfaces. 2014 Jul 9;6(13):10274-82. doi: 10.1021/am501657j. Epub 2014 Jun 23.
High oxygen permeability and good thermochemical stability of oxygen-transporting membranes (OTMs) are two main requirements concerning the applicability of these devices in chemical processes, such as CO2 capture using the oxyfuel concept or catalytic membrane reactors. In this work, a single-phase perovskite-type membrane Pr0.6Sr0.4Co0.5Fe0.5O3-δ (PSCF) with 0.6-mm thickness was subjected to periodic thermal cycling in the temperature range between 850 and 1000 °C in a 1000-h long-term permeation test with pure CO2 as the sweep gas. The results of this long-term permeation operation revealed a stepwise increase in oxygen permeation values at 1000 °C after each thermal cycle, reaching from 1.38 cm(3) (STP) min(-1) cm(-2) in the first cycle to 1.75 cm(3) (STP) min(-1) cm(-2) in the fourth cycle. Furthermore, the membrane showed very good CO2 stability at 900 °C and above. Despite a partial decrease in oxygen permeation fluxes at 850 °C, a steady state of 0.25 cm(3) (STP) min(-1) cm(-2) was reached and maintained for more than 100 h. The newly developed PSCF membrane also exhibited a higher oxygen permeation flux with He and CO2 sweeping at all measured temperatures compared to a similar La0.6Sr0.4Co0.8Fe0.2O3-δ (LSCF) membrane.
氧传输膜（OTMs）具有高透氧率和良好的热化学稳定性，是这些装置在化学过程中应用的两个主要要求，例如使用氧燃料概念的二氧化碳捕集或催化膜反应器。在本工作中，对厚度为0.6毫米的单相钙钛矿型膜Pr0.6Sr0.4Co0.5Fe0.5O3-δ（PSCF）在850至1000°C的温度范围内进行周期性热循环，以纯二氧化碳作为吹扫气进行1000小时的长期渗透测试。该长期渗透操作的结果表明，在每次热循环后，1000°C时的氧渗透值呈逐步增加，从第一个循环中的1.38 cm(3) （标准温度和压力）min(-1) cm(-2) 增加到第四个循环中的1.75 cm(3) （标准温度和压力）min(-1) cm(-2) 。此外，该膜在900°C及以上表现出非常好的二氧化碳稳定性。尽管在850°C时氧渗透通量有所部分下降，但仍达到并维持了0.25 cm(3) （标准温度和压力）min(-1) cm(-2) 的稳态超过100小时。与类似的La0.6Sr0.4Co0.8Fe0.2O3-δ（LSCF）膜相比，新开发的PSCF膜在所有测量温度下用氦气和二氧化碳吹扫时也表现出更高的氧渗透通量。
