Preparation and Testing of Microporous Glass Membranes for Gas Separations

CTS-0085480气体分离用微孔玻璃膜的制备和测试乔治R.加州理工学院简介 采用相分离玻璃浇铸技术，研制出了适用于气体分离的支撑玻璃膜。通过首先在玻璃组分（Na 2 O-B 2 O3-SiO 2-Al 2 O3）的悬浮液中浸涂平坦或管状多孔氧化铝载体来制备膜。然后将颗粒涂层加热以使组分反应成5-10 mm厚的连续玻璃膜。冷却后，玻璃分离成两个相互缠绕的相，一个可溶于酸，另一个不溶于酸。在酸中浸提除去固相，留下作为多孔膜的不溶性相，其孔径根据初始组成以及加工条件从低于1 nm变化到10 nm。为了实现高的膜选择性，必须确定产生小于1 nm的孔径的组合物。为此目的，膜试样正在广泛的玻璃组合物范围内制备。使用常规的膜制备技术，这样的努力是禁止的。在这个项目中，并行处理被用来快速和彻底地探索一个大的多组分组成空间。 具体地说，阵列的几个小的圆形膜，每个不同的组成，同时沉积在一个单一的氧化铝盘。在热处理和浸提之后，通过扫描电子显微镜表征膜，并测试膜对各种气体混合物的渗透性和选择性，所述气体混合物包括CO2-CH 4和C1-C4烃的组合。使用质谱仪探针连续进行渗透测试。在该项目的过程中，正在处理大约50个圆盘，每个圆盘含有30个以上的膜。 无机膜为天然气和石化等材料的工业加工以及燃料电池中所需的气体分离提供了实用且节能的技术。一种类型的这种耐用膜由支撑在多孔陶瓷板或管上的薄微孔玻璃膜组成。 为了获得良好的膜性能，有必要将孔径降低到分子尺寸，并且为此目的，有必要测试广泛的制备条件。这种必要的大量实验工作通过常规技术将是极其耗时的。在该项目中，正在开发在单个支撑盘上同时沉积和测试许多膜制剂的技术。通过这种平行或组合处理提供的增加的生产率允许评估超过一千种膜组合物，以优化其分离性能。这种优化的膜将有助于提高天然气和石油工业分离的效率和经济性。

CTS-0085480Preparation and Testing of Microporous Glass Membranes for Gas Separations George R. GavalasCalifornia Institute of TechnologyAbstract Supported glass membranes suitable for gas separations are developed using phase-separated-glass casting techniques. Membranes are made by first dip-coating flat or tubular porous alumina supports in a suspension of the glass components (Na2O-B2O3-SiO2-Al2O3). The particle coating is then heated to react the components into a continuous glass film 5-10 mm thick. Upon cooling, the glass separates into two intertwined phases, one soluble in acid and the other insoluble. Leaching in acid removes the solid phase, leaving behind the insoluble phase as a porous film with pore sizes varying from below 1 nm to 10 nm depending on the initial composition as well as on the processing conditions. To achieve high membrane selectivity it is essential to identify compositions that give pore size below 1 nm. For this purpose membrane specimens are being prepared over a broad range of glass compositions. Such an effort is prohibitive using conventional membrane-preparation techniques. In this project parallel processing is used to explore quickly and thoroughly a large multicomponent composition space. Specifically, arrays of several small circular membranes, each of different composition, are deposited simultaneously on a single alumina disk. After thermal treatment and leaching the membranes are characterized by scanning electron microscopy and tested for permeance and selectivity with various gas mixtures, including CO2-CH4 and combinations of C1-C4 hydrocarbons. The permeation testing is carried out serially using a mass spectrometer probe. Approximately fifty disks, each containing upwards of thirty membranes, are being processed in the course of this project. Inorganic membranes offer a practical and energy-efficient technology for gas separations needed in industrial processing of materials such as natural gas and petrochemicals and in fuel cells. One type of such durable membranes consists of thin microporous glass films supported on porous ceramic plates or tubes. To achieve good membrane properties it is necessary to bring the pore sizes down to molecular dimensions, and for this purpose it is necessary to test a wide range of preparation conditions. This necessarily extensive experimental effort would be extremely time consuming by conventional techniques. In this project techniques for simultaneously depositing and testing a number of membrane formulations on a single support disk is being developed. The increased productivity afforded by this parallel, or combinatorial, processing permits evaluation of over one thousand membrane compositions in order to optimize their separation properties. Such optimized membranes will contribute to improved efficiency and economy in separations pertaining to the natural-gas and petroleum industries.