直孔三明治结构GDC-LSF双相复合透氧膜制备和性能研究

Preparation and Property of GDC-LSF Dual-phase Composite Membrane with Straight Pores and Sandwich Structure

致密陶瓷透氧膜因在氧气制备和涉氧化工过程中的潜在重要应用而备受关注。本研究采用相转化流延/叠层/烧结工艺制备了三明治结构Gd_(0.1)Ce_(0.9)O_(2–δ)-La_(0.6)Sr_(0.4)FeO_(3–δ)(GDC-LSF)双相复合陶瓷透氧膜,其中部为起氧分离作用、厚度80μm的致密功能层,两侧为厚度420μm的直孔结构支撑层。采用浸渍法在支撑层内壁修饰Nd_(2)NiO_(4)+δ(NNO)纳米颗粒。在膜的一侧通入空气,另一侧通入氦气作为载气,测得900℃时氧渗透通量高达1.53 mL·cm^(−2)·min^(−1)。将氦气切换为CO_(2),测得氧渗透通量为0.6 mL·cm^(−2)·min^(−1),氧渗透在长达90 h的时间内保持稳定。该透氧膜经历70余次热循环(800~900℃)后仍保持完好。本研究表明:直孔三明治结构GDC-LSF透氧膜具有良好的氧渗透性能、化学稳定性和热机械性能,有望用于氧气分离和富氧燃烧/CO2捕获。

The dense ceramic oxygen-permeable membrane has attracted much attention due to its potential applications in production of oxygen from air and manipulation of oxygen-consuming industrial chemical processes.In the present study,Gd_(0.1)Ce_(0.9)O_(2–δ)-La_(0.6)Sr_(0.4)FeO_(3–δ)(GDC-LSF)dual-phase composite membrane was prepared using the phase-inversion tape casting/lamination/sintering method.The as-prepared membrane consisted of an 80μm thick dense oxygen separation layer sandwiched between two 420μm thick finger-like porous support layers.The inner surface of the support layers was further modified with Nd2NiO4+δ(NNO)nanoparticles using the impregnation method.An oxygen permeation flux of 1.53 mL·cm^(−2)·min^(−1)was measured at 900℃by exposing one side of the membrane to a flowing air stream and the other side to a flowing He stream.When CO_(2)was used as sweep gas,an oxygen permeation flux of 0.6 mL·cm^(−2)·min^(−1)was obtained,and no decrease in the flux was observed during 90 h of testing.The membrane remained intact after experiencing over 70 thermal cycles between 800 and 900℃.GDC-LSF dual-phase composite membrane with straight pores and sandwich structure has demonstrated satisfactory combination of oxygen permeability,chemical stability and thermal mechanical strength,promising for applications in separation of oxygen from air and oxy-fuel combustion with CO_(2)capture.