BRIGE Exploiting crystalline framework flexibility to enable energy efficient entropically selective separations

技术说明：该项目旨在设计和开发一种微孔材料，该材料可以利用随温度变化的分子筛现象成功地压裂多组分气流。 沸石咪唑酯骨架（ZIF）是一类微孔材料，其由于可获得宽范围的有机咪唑酯连接体而在化学上是可调的。 ZIF晶体的孔是柔性的，这是由于咪唑酯连接基围绕框架内的配位键旋转。 在该项目中要探索的一个中心假设是ZIF孔的灵活性是温度依赖性的，这导致可调的筛分孔径，可以实现扩散气体物质的熵分离。 在这项工作中创建的ZIF将被集成到最先进的多孔纤维复合材料中，独特地实现熵分离过程。 熵分离面临的主要挑战是同时保持低的气体压降和控制系统中的总传质的晶内扩散。 高度多孔的纤维复合材料将允许气体在晶体中扩散，以控制在低气压降下的过程，这在传统的吸附系统中是不可行的。更广泛的意义和重要性：本项目提出的工作旨在创建一个新的材料平台，使能源效率高的回收有价值的天然气液体（NGL）从非传统的天然气来源。 目前的天然气回收系统是主要的能源消耗？是吗？标准？NGL回收厂每天生产约750吨NGL，消耗的能源相当于1万户家庭的供暖。 该项目旨在将这种能量损失减少3 - 5倍。 这一目标将通过创造新的晶体材料来实现，该晶体材料将NGL分子从原始天然气分子中物理地“筛”出来。 物理筛分过程依赖于通过新型晶体材料创建微观途径-在这些微观途径中创建和理解NGL分子运动是该项目的主要推动力。 为了能够广泛采用所提出的节能NGL回收系统，新型晶体材料将被集成到基于合成纤维的设备中，这些设备非常适合大规模生产。 这些基于纤维的NGL回收设备的创建-该项目的第二个主要重点-是受到工业合成纺织纤维生产工艺的启发。 这些基于纤维的NGL回收设备的大规模生产可能会导致国内“先进”的制造业工作，并为美国在NGL的节能回收领域提供领先优势。这里建立的基本科学和技术见解将指导未来节能气体分离和净化工艺的设计，包括从稀释源回收天然气，化学生产和氢气生产。该项目的主要目标是将年轻女性和代表性不足的少数民族引入STEM领域，以提高加入这些领域的倾向。PI将通过在亚特兰大当地市中心初中和高中的推广相结合，并利用格鲁吉亚理工学院的现有项目来实现这一目标。 BRIGE奖将允许PI实施旨在实现这些目标的教育推广计划。 私家侦探？的全面计划，推广和保留妇女和代表性不足的少数民族有三个主要方面：i）通过在课堂上的示范和讲座，在内城亚特兰大初中和高中和积极参与格鲁吉亚技术推广？的夏季工程学院，ii）使用BRIGE支持女性和代表性不足的少数民族研究助理，以及iii）利用格鲁吉亚理工学院的现有项目，在实验室内外对女性和代表性不足的少数民族进行辅导，指导和专业发展。PI将定期评估他的外展工作的成功，并根据教师，学生和研究助理的反馈调整他的计划。这项研究已经通过工程学征集的扩大参与研究启动赠款资助，这是工程教育和中心部门的工程学扩大参与计划的一部分。

Technical Description:This project seeks to design and develop a microporous material that can successfully fractionate multi-component gas streams using a temperature-dependent molecular sieving phenomenon. Zeolitic imidazolate frameworks (ZIFs) are a class of microporous material that are chemically tunable due to the availability of a wide spectrum of organic imidazolate linkers. The pores of ZIF crystals are flexible as a result of imidazolate linker rotation around coordination bonds within the framework. A central hypothesis to be explored in this project is that the ZIF pore flexibility is temperature-dependent, which results in a tunable sieving aperture that can enable an entropic separation of diffusing gas species. The ZIFs created in this work will be integrated into state-of-the-art porous fiber composites that uniquely enable the entropic separation process. A primary challenge facing entropic separations is simultaneously maintaining low gas pressure drop and intracrystalline diffusion controlling the overall mass transfer in the system. The highly porous fiber composites will allow gas diffusion in the crystal to control the process at low gas pressure drops, which is not feasible in traditional adsorption systems.Broader Signficance and Importance:The work proposed in this project aims to create a new platform for materials that enable energy efficient recovery of valuable natural gas liquids (NGLs) from non-conventional natural gas sources. The current NGL recovery systems are major energy consumers?a ?standard? NGL recovery plant that produces approximately 750 tons of NGLs per day will consume energy equivalent to the heating of 10,000 homes. This project aims to reduce this energy loss by a factor of 3-5. This goal will be achieved by creating novel crystalline materials that physically "sieve" the NGL molecules from raw natural gas molecules. The physical sieving process relies on the creation of microscopic pathways through the novel crystalline materials--creation and understanding of NGL molecular movement in these microscopic pathways is a major thrust of this project. To enable wide-spread adoption of the proposed energy-efficient NGL recovery system, the novel crystalline materials will be integrated into synthetic fiber-based devices, which are ideally suited for mass manufacturing. Creation of these fiber-based NGL-recovery devices--a second major focus of this project--is inspired by industrial synthetic textile fiber production processes. Large-scale production of these fiber-based NGL-recovery devices could potentially lead to domestic "advanced" manufacturing jobs and provide the USA with a head start in the field of energy-efficient recovery of NGLs. The fundamental scientific and technological insights established here will guide the design of future energy efficient gas separation and purification processes, including natural gas recovery from dilute sources, chemical production, and hydrogen production. Broadening Participation of Underrepresented Groups in Engineering A primary goal of this project is to introduce young women and under-represented minorities to STEM fields in an effort to increase inclination to join these fields. The PI will achieve this goal through a combination of outreach at local inner city middle and high schools in Atlanta, and by leveraging existing programs at Georgia Tech. The BRIGE award will allow the PI to implement his educational outreach plans which aim to achieve these goals. The PI?s comprehensive plan for outreach and retention of women and under-represented minorities has three primary facets: i) Outreach through in-class demonstrations and lectures at inner city Atlanta middle and high schools and active participation in Georgia Tech?s Summer Engineering Institute, ii) use BRIGE support for female and under-represented minority research assistants, and iii) leveraging existing programs at Georgia Tech to engage in mentoring, guidance and professional development of female and under-represented minorities both in and out of the laboratory. The PI will periodically assess the success of his outreach efforts and adjust his program according to feedback from teachers, students, and research assistants.This research has been funded through the Broadening Participation Research Initiation Grants in Engineering solicitation, which is part of the Broadening Participation in Engineering Program of the Engineering Education and Centers Division.