کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
637860 1456154 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Oxygen permeation, thermal and chemical expansion of (La, Sr)(Fe, Ga)O3−δ perovskite membranes
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
Oxygen permeation, thermal and chemical expansion of (La, Sr)(Fe, Ga)O3−δ perovskite membranes
چکیده انگلیسی

Dense ceramic membranes made from mixed conductors are interesting because of their potential applications for methane conversion into syngas (H2 and CO mixture). Such membranes need to present a low differential dimensional variation between the opposite faces submitted to a large gradient of oxygen partial pressure, in order to minimize mechanical stresses generated through the membrane thickness. Besides, high oxygen permeability is required for high methane reforming rate. La(1−x)SrxFe(1−y)GayO3−δ materials fulfil these two main requirements and were retained as membranes in catalytic membrane reactors (CMR). The variations of expansion and oxygen permeation of La(1−x)SrxFe(1−y)GayO3−δ perovskite materials with the partial substitution of lanthanum and iron cations, temperature and oxygen partial pressure, were studied. For low temperatures (<800 °C), the thermal expansion coefficient (TEC) value of La(1−x)SrxFe(1−y)GayO3−δ materials is independent of cation substitution and of oxygen partial pressure in the range tested (10−5 to 0.21 atm). For higher temperatures (>800 °C), TEC, then dimensional stability of the membrane, and oxygen permeation of La(1−x)SrxFe(1−y)GayO3−δ materials, are significantly affected by Sr content and oxygen partial pressure. Ga has a stabilisation effect on the TEC and has no influence on oxygen permeation flux. A good compromise between dimensional stability and oxygen permeation of materials was found to be La0.7Sr0.3Fe0.7Ga0.3O3−δ composition.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Membrane Science - Volume 319, Issues 1–2, 1 July 2008, Pages 185–191
نویسندگان
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