SBIR Phase II: Zeolite Membranes for Gas Separation

这个小企业创新研究第二阶段项目的目标是开发和演示基于沸石的无机膜模块，该模块使用分子筛分机制进行气体分离。在第一阶段，TDA研究公司（TDA）开发了生长ZSM-5致密连续薄膜所需的技术。ZSM-5薄膜在单晶二氧化硅和氧化铝衬底上成功生长。薄膜厚度约为100am，即使在热循环时也能保持与衬底的粘合。然后在多孔硅片上生长ZSM-5薄膜。在煅烧前，发现薄膜是气密的。煅烧后，采用Ar、N2、i-C4H、o和SF6作为测试气体进行渗透测量。膜具有粘附性、无缺陷性，其渗透数据和计算的分离因子符合分子筛分机制。在二期项目中，TDA将开发膜氧化铝单体涂层技术，以开发高效、经济的无机气体分离膜。为了提高膜的气体分离性能，将采用化学方法对膜的孔径进行优化。19通道Membralox氧化铝模块将用ZSM-5和丝光沸石薄膜进行修饰，孔径针对选定的气体分离进行优化，并对模块的性能进行评估。沸石膜具有高分离比，极高的通量，并且可以在高温和腐蚀性化学环境中工作，这些环境会破坏聚合物膜。因此，沸石改性氧化铝膜将在恶劣条件下的气体分离中首次应用。其他潜在的高价值应用包括用作先进面包店中的固体电解质，化学传感器中的选择性薄膜以及先进的光学和电子设备。

DMI-9505382 Bai The objective of this Small Business Innovation Research Phase II project is to develop and demonstrate zeolite based inorganic membrane modules that carry out gas separations using a molecular sieving mechanism. In Phase I, TDA Research Inc. (TDA) developed the techniques necessary to grow dense continuous films of ZSM-5. ZSM-5 films were successfully grown on single crystal silica and alumina substrates. The films were approximately 100 Am thick and remained bonded to the substrate even when thermally cycled. ZSM-5 films were then grown on porous silica discs. Before calcination, the films were found to be gas tight. Following calcination, permeation measurements were carried out using Ar, N2, i-C4H,o, and SF6 as the test gases. The membranes were adherent, defect free, and the permeance data and calculated separation factors were consistent with a molecular sieving mechanism. In the Phase II project, TDA will develop techniques to coat Membralox alumina monoliths in order to develop efficient cost effective inorganic gas separation membranes. In order to improve the gas separation properties of the membranes, the pore sizes will be optimized using chemical means. Nineteen channel Membralox alumina modules will be modified with ZSM-5 and mordenite films, the pore sizes optimized for selected gas separations, and the performance of the module will be evaluated. Zeolite membranes have high separation ratios, extremely high fluxes, and can operate in high temperature and aggressive chemical environments that would destroy polymeric membranes. Therefore, zeolite modified alumina membranes will find their first applications in gas separations under aggressive conditions. Other potential high value applications include use as solid electrolytes in advanced bakeries, as selective films in chemical sensors, and in advanced optical and electronic devices.