Experimental investigation and mathematical modeling of oxygen permeation through dense Ba_0.5Sr_0.5Co_0.8Fe_0.2O_{3鈭?span style='font-style: italic'>未} (BSCF) perovskite-type ceramic membranes

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• 作者：Amir Behrouzifar^a ; Amir Atabak Asadi^a ; Toraj Mohammadi^a ; ^{torajmohammadi@iust.ac.ir} ; Afshin Pak^b
• 关键词：C. Diffusion ; D. Perovskite ; E. Membranes ; Mathematical modeling
• 刊名：Ceramics International
• 出版年：2012
• 期刊代码：13_02728842
• 类别：ms
• 出版时间：August, 2012
• 卷：38
• 期：6
• 页码：4797-4811
• 文件大小：1747 K

摘要

Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3鈭?em>未 (BSCF) perovskite powder was synthesized via EDTA/citrate complexation method. BSCF membranes were formed by pressing powder at 400 MPa and sintering at 1100 掳C for 10 h. XRD patterns showed that a high pure powder with cubic structure was obtained. SEM micrographs revealed that the membranes are dense with large grains. Effects of temperature, feed and permeate side oxygen partial pressures, flow rates and membrane thickness on oxygen permeation flux were studied experimentally. A Nernst-Planck based mathematical model, including surface exchange kinetics and bulk diffusion, was developed to predict oxygen permeation flux. Considering non-elementary surface reactions and introducing system hydrodynamics into the model resulted in an excellent agreement (RMSD = 0.0617, AAD = 0.0487 and R² = 0.985) between predicted and measured fluxes. The results showed that oxygen permeation flux increases with temperature, feed side oxygen partial pressure and flow rates, however decreases with permeate side oxygen partial pressure and membrane thickness. Contribution of feed side surface exchange reactions, bulk diffusion and permeate side surface exchange reactions resistances in the total resistance are in the range of 8-32%, 10-81%and 11-59%, respectively. Permeation rate-limiting step was determined using the membrane dimensionless characteristic thickness.