Template-Free Synthesis of Oriented Zeolite Membranes with Improved High-Activity Molecular Separation Characteristics

无模板合成具有改进的高活性分子分离特性的定向沸石膜

• 批准号: 2031087
• 负责人: Jerry Lin
• 金额: $ 34.11万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2031087&HistoricalAwards=false
• 关键词: Template; Free; Synthesis; Oriented; Zeolite

MFI-type zeolite membranes are among the most stable microporous materials with molecular sieving capabilities. High-performing MFI zeolite membranes on hollow fiber supports will enable development of new and more efficient separation technologies for the chemical and petroleum industries by significantly improving purity, heightening flux, and minimizing capital and operating costs. Due to the unique pore structure of MFI zeolite crystals, b-oriented MFI zeolite membranes offer better molecular sieving separation characteristics than randomly oriented polycrystalline MFI zeolite membranes. These properties make b-oriented MFI zeolite membranes highly attractive for industrial applications including separation of xylene isomers. However, high quality b-oriented MFI zeolite membranes have been fabricated only on disk supports by complex synthesis methods that include the use of costly organic-templates. Such templated MFI zeolite membranes also exhibit unfavorable pressure dependence of separation properties, characterized by a decrease of permeability and selectivity with increasing feed xylene vapor pressure. Several challenges must be addressed to further advance the synthesis of b-oriented MFI zeolite membranes beyond the laboratory scale. These challenges include synthesis of high-quality b-oriented MFI zeolite membrane on supports that can be arranged into modules with high packing density by cost-effective and scalable methods and understanding the separation characteristics of b-oriented MFI zeolite membranes in contact with feed mixtures at high vapor pressures. This project will therefore develop methods for facile syntheses of high-quality b-oriented MFI zeolite membranes on hollow fiber supports and study the synthesis-structure-separation property relationship of such grown b-oriented MFI zeolite membranes for use in the separation of xylene isomers at high vapor pressures. The knowledge developed through this project will be translatable to other-oriented crystalline microporous membranes for other separation processes. In addition to graduate student training opportunities, the broader impacts of the project include a public outreach activity aimed at demonstrating how inorganic membranes work.This project will focus on the synthesis of b-oriented MFI zeolite membranes on alumina hollow fiber supports by a scalable, template-free synthesis method. The method will consist of filtration “seeding” using 2-dimensional MFI zeolite nanosheets, followed by template-free secondary growth. Preparation of a zeolite layer using 2-dimensional MFI zeolite nanosheets by filtration offers a versatile and scalable method of fabrication leading to a high-quality b-oriented MFI zeolite seed layer for secondary growth. The MFI zeolite seed layer will be preferentially grown into a b-oriented MFI zeolite membrane with a template-free synthesis solution of optimized composition. The use of a template-free solution produces zeolite membranes of higher quality by minimizing or eliminating intercrystalline gaps that permit non-selective diffusion of gas or liquid mixtures. It also reduces the number of synthesis steps and eliminates the use of costly organic templates. Synthesis of templated and template-free, randomly and b-oriented MFI zeolite membranes enables a systematic study of the synthesis-structure-separation property relationship of the MFI zeolite membranes. In particular, the study will be focused on understanding the effects crystal shape/orientation, intercrystalline microstructure, and zeolite framework composition on the feed pressure dependence of xylene permeability and selectivity of MFI zeolite membranes. This work will also identify conditions for the synthesis of high-performance b-oriented MFI zeolite membranes for effective separation of xylene mixture under industrially relevant conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

MFI型分子筛膜是最稳定的具有分子筛分能力的微孔材料之一。中空纤维支撑体上的高性能MFI分子筛膜将通过显著提高纯度、提高通量并将资本和运营成本降至最低，从而为化工和石油行业开发新的、更高效的分离技术。由于MFI沸石晶体独特的孔结构，b取向的MFI分子筛膜比随机取向的多晶MFI分子筛膜具有更好的分子筛分离特性。这些特性使b取向的MFI分子筛膜在工业应用中具有极大的吸引力，包括对二甲苯异构体的分离。然而，高质量的b取向MFI分子筛膜只能通过复杂的合成方法在圆盘载体上制备，其中包括使用昂贵的有机模板。这种模板化MFI分子筛膜的分离性能也表现出不利的压力依赖性，其特征是渗透率和选择性随着进料二甲苯蒸气压的增加而降低。为了进一步推动b取向MFI分子筛膜的合成超越实验室规模，必须解决几个挑战。这些挑战包括在载体上合成高质量的b取向MFI沸石膜，这些载体可以通过经济高效和可扩展的方法排列成具有高堆积密度的模块，以及了解b取向MFI沸石膜在高蒸汽压下与进料混合物接触的分离特性。因此，本项目将开发在中空纤维载体上简便地合成高质量的b取向MFI分子筛膜的方法，并研究这种生长的b取向MFI分子筛膜的合成-结构-分离性能之间的关系，用于在高蒸汽压下分离二甲苯异构体。通过该项目开发的知识将可转化为用于其他分离过程的其他取向的结晶微孔膜。除了研究生培训机会，该项目的更广泛影响包括一项旨在展示无机膜如何工作的公共推广活动。该项目将专注于通过一种可扩展的、无模板的合成方法在氧化铝中空纤维载体上合成b取向的MFI沸石膜。该方法将包括使用二维MFI沸石纳米片过滤“播种”，然后无模板二次生长。通过过滤使用二维MFI沸石纳米片制备沸石层提供了一种通用且可扩展的制备方法，从而获得了用于二次生长的高质量的b取向MFI沸石种子层。采用优化组成的无模板剂合成液，将MFI沸石种子层优先生长成b取向的MFI分子筛膜。使用无模板溶液通过最小化或消除允许气体或液体混合物非选择性扩散的晶间间隙来产生更高质量的沸石膜。它还减少了合成步骤的数量，并消除了昂贵的有机模板的使用。模板化、无模板化、无规和b取向的MFI分子筛膜的合成使得系统地研究MFI分子筛膜的合成-结构-分离性能之间的关系成为可能。特别是，这项研究将集中于了解晶体形状/取向、晶间微结构和沸石骨架组成对进料压力对MFI分子筛膜透过率和选择性的影响。这项工作还将确定在工业相关条件下合成高性能b取向MFI沸石膜以有效分离二甲苯混合物的条件。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Zeolite membrane separators for fire-safe Li-ion batteries – Effects of crystal shape and membrane pore structure

• DOI: 10.1016/j.memsci.2023.121743
• 发表时间: 2023-05
• 期刊: Journal of Membrane Science
• 影响因子: 9.5
• 作者: Dheeraj Ram Lingam Murali;Fateme Banihashemi;Jerry Y. S. Lin

B-oriented MFI zeolite membranes for xylene isomer separation - Effect of xylene activity on separation performance

用于二甲苯异构体分离的 B 取向 MFI 沸石膜 - 二甲苯活性对分离性能的影响

• DOI: 10.1016/j.memsci.2022.120492
• 发表时间: 2022
• 期刊: Journal of membrane science
• 影响因子: 9.5
• 作者: Fateme Banihashemi;Jerry Y.S. Lin
• 通讯作者: Jerry Y.S. Lin