Nanocomposite membranes functionalized with facilitated transport and molecular sieving for challenging gas separations

拟议的研究将寻求一种变革性的方法，开发具有便利运输和分子筛选功能的纳米复合膜，以实现气体分离，这对加拿大的工业很重要，但目前的技术很难实现。具体而言，本研究旨在开发具有便利运输和分子筛分功能的尖端混合基质纳米复合膜，专门用于(1)烯烃/石蜡分离（取代或补充传统的高能耗低温蒸馏），(2)从烟气中捕获二氧化碳（用于控制温室气体排放），以及(3)从CH4中去除N2以升级次优质天然气。烯烃分离和天然气脱氮是天然气工业中最具挑战性的两个操作，而烟气分离对于碳捕获以减少温室气体排放至关重要。基于我们通过纳米结构和功能化在创新膜方面取得的成就，这项工作将在推进具有挑战性的气体分离的可扩展膜方面取得突破，这些都与加拿大的石化、资源和能源部门直接相关。促进剂的基本方面，分子筛选材料，以及这两种功能在膜上的协同作用，以加强分离将被研究。为了促进烯烃和二氧化碳的运输，促进剂将作为“载体”在膜上运输目标气体分子。将选择银离子和胺分子（包括单体胺和聚合胺）分别作为烯烃和CO2的促进剂，以开发特定的烯烃-银和CO2-胺相互作用。对于N2/CH4的分离，由于缺乏合适的促进剂，将采用具有微双相分离纳米结构的嵌段共聚物作为基膜，实现基于离散扩散的N2/CH4分离。在所有情况下，膜将与适当的MOF/ZIF筛结合，通过分子筛进一步增加分离。该混合基质纳米复合膜由于易于运输和分子筛分（用于烯烃和二氧化碳）的结合，以及基础聚合物和MOF/ZIF筛对N2/CH4气体对的双重离散扩散率，预计将表现出优异的性能。将建立一种成分-纳米结构-电选择性的关系，以指导这些新型膜的实际应用。这项研究具有很强的原创性和创新性；这是第一次将促进运输与膜内的分子筛选结合起来。这项工作不仅直接解决了加拿大对先进膜的工业需求，还将为提高知识水平和培养高素质人才做出重大贡献。

The proposed research will pursue a transformative approach to developing nanocomposite membranes functionalized with facilitated transport and molecular sieving to effect gas separations that are important to Canadian industries, but challenging to carry out with current technologies. Specifically, this research aims at developing cutting-edge mixed-matrix nanocomposite membranes with both facilitated transport and molecular sieving functionalities tailored for (1) olefin/paraffin separation (to replace or complement with traditional energy-intensive cryogenic distillation), (2) CO2 capture from flue gas (for greenhouse gas emission control), and (3) removal of N2 from CH4 for upgrading sub-quality natural gas. Olefin separation and natural gas denitrogenation are two most challenging operations in the gas industry, and flue gas separation is critical for carbon capture to mitigate greenhouse gas emission. Built on our accomplishments in innovative membranes via nanostructuring and functionalization, this work will lead to breakthroughs in advancing up-scalable membranes for these challenging gas separations, which are all directly related to Canada's petrochemical, resource and energy sectors. The fundamental aspects of the facilitating agents, the molecular sieving materials, and the synergy of both functions in the membrane for enhanced separation will be investigated. For facilitated transport of olefin and CO2, the facilitating agents will function as a "carrier" to transport the target gas molecules across the membrane. Silver ions and amine molecules (both monomeric and polymeric amines) will be chosen as the facilitating agents for olefin and CO2, respectively, to exploit the specific olefin-silver and CO2-amine interactions. For N2/CH4 separation, suitable facilitating agents are lacking, and instead block copolymers with micro-biphase separated nanostructures will be used as the base membrane to achieve N2/CH4 separation based on discretive diffusion. In all cases, the membranes will be incorporated with appropriate MOF/ZIF sieves to further augment the separation via molecular sieving . The resulting mixed matrix nanocomposite membranes are expected to exhibit superior performance due to combined facilitated transport and molecular sieving (for olefin and CO2 applications) and the double discretive diffusivities of the base polymer and MOF/ZIF sieves towards N2/CH4 gas pair. A composition-nanostructure-permselectivity relationship will be established to guide development of these novel membranes for practical applications. This research is highly original and innovative; this is the first time that facilitated transport is integrated with molecular sieving within a membrane. Not only does this work directly address Canada's industrial needs for advanced membranes, it will also contribute significantly to advancing knowledge and training of highly qualified personnel.