Syngas Production by Partial Oxidation of Methane with Oxygen Permeable Membrane

本研究通过三种方法(1)不对称膜的制备，(2)制备方法的优化，(3)新材料的研究，提高了膜的透氧性。(1)研究了在多孔α-Al_2O_3衬底上制备SrFeCo_(0.5)&GT；O_x(SFC2)非对称薄膜的方法。虽然通过重复制备得到了气密膜，但由于膜材料和基质之间的固相反应或由于SFC2的组成不同，这些膜没有表现出高的氧通量。为了防止此类问题，我们建立了一种新的制备方法。用SFC2粉末制备致密层，用SFC2粉末与乙基纤维素混合制备多孔支撑层。同时对SFC2粉末和混合物进行压制和焙烧。用该方法制备的致密层的最小厚度为0.1 mm。不对称膜比对称膜具有更大的氧通量。通过这些膜的氧通量随着致密层厚度的减小而增加。(2)用三种不同的方法(A)固相反应法、(B)蒸发干燥法和(C)柠檬酸和EDTA相结合的方法制备了SFC2膜。络合法。氧通量按(A)&lt；(B)&lt；(C)的顺序增加。考察了制备条件对氧通量的影响。对母粉进行反复焙烧、研磨或在较高温度下烧结均可提高氧流量。(3)用另一种稀土元素Pr、Nd、Sm替代La_&lt；0.4&gt；Ba_&lt；0.6&gt；Fe_&lt；0.8&gt；Co_&lt；0.2&gt；O_&lt；3-δ&gt；中的La。但并未获得比La_&lt；0.4&gt；Ba_&lt；0.6&gt；Fe_&lt；0.8&gt；Co_&lt；0.2&gt；O_&lt；3-δ&gt；膜更高的氧通量。现在，我们通过将其应用于膜反应器来评价本研究中制备的膜。

In this study, oxygen permeability was improved by three methods (1)Preparation of asymmetric membranes, (2)Optimization of preparation methods, and (3)Investigation of new materials. (1)We investigated the preparation of SrFeCo_<0.5>O_x(SFC2) asymmetric membranes on porous α-alumina substrates. Though gas-tight membranes were obtained by repeating the preparation, these membranes did not show high oxygen flux due to solid-state reaction between membrane materials and substrates or due to differences of compositions from SFC2. To prevent such problems, we established a new preparation method. The dense layer was prepared with SFC2 powder, and the porous support layer was prepared using SFC2 powder mixed with ethyl cellulose. The SFC2 powder and the mixture were simultaneously pressed and calcined. The minimum thickness of the dense layer prepared by this method was 0.1 mm. The asymmetric membranes gave greater oxygen flux than the symmetric membrane. And the oxygen fluxes through these membranes increased with decreasing the thickness of dense layer. (2)SFC2 membranes were synthesized with powders prepared by three different methods, (a)a solid-state reaction method, (b)an evaporation-to-dryness method, and (c)a combined citrate and EDTA. Complexing method. Oxygen fluxes increased in the order of (a)<(b)<(c). Influence of preparation conditions on oxygen flux was investigated. The oxygen flux could be improved by repeated calcination and grinding of parent powder or by sintered at a higher temperature. (3)La in La_<0.4>Ba_<0.6>Fe_<0.8>Co_<0.2>O_<3-δ> was substituted by another rare earth element such as Pr, Nd, Sm. The higher oxygen flux than La_<0.4>Ba_<0.6>Fe_<0.8>Co_<0.2>O_<3-δ> membrane, however, was not obtained. Now we evaluating membranes prepared in this study by applying to a membrane reactor.