EFRI DChem: Next-generation Low Global Warming Refrigerants

EFRI DCHEM分布式化学制造项目名为Earth(氢氟烃环境应用研究)，将在一个协调的框架内使用高保真实验、先进的计算机模拟和严格的分析方法来发现、合成和测试一种名为离子液体的新型流体，这种液体可用于分离、回收高全球变暖潜力(GWP)制冷剂混合物，并将其转化为安全产品。这项研究将由位于堪萨斯大学、圣母大学、德克萨斯农工大学和罗格斯大学的研究人员组成，与布鲁克海文国家实验室、橡树岭国家实验室和国家标准与技术研究所以及两个行业合作伙伴(化学和Iolitec)合作进行。鉴于必须从市场上淘汰大量全球变暖潜能值高的制冷剂，该项目的技术、经济和环境影响是相当大的。回收制冷剂的市场价值超过10亿美元，阻止高全球变暖潜能值制冷剂排放到地球大气层相当于减少1.75亿吨二氧化碳(或每年5000万辆汽车的排放量)。该项目有可能为制冷剂业务带来经济效益，并为美国100多家获得EPA认证的回收商提供分布式化学制造流程。该项目将采用多方面战略，最大限度地扩大与更广泛的科学界的传播和知识共享。这四所牵头院校致力于提供一个安全包容的环境，将招收5名博士生、1名博士后研究员和8名本科生。这些研究人员将接受科学和工程方面的跨学科培训，参加STEM研讨会和安全会议，并在大学、公司和国家实验室的合作伙伴中实习。该项目将提供回收和重新利用高全球变暖潜质制冷剂所需的基本知识和创新。该项目建立在离子液体(ILS)的可调溶剂化性质基础上，以实现对共沸HFC混合物的分离，这是其他材料不可能实现的。两个主要目标是(1)为复杂系统设计具有高选择性和高容量的化学分离；(2)了解化学分离系统中发生的时间变化。六个基本目标将集成性能测量和状态方程建模(目标1)、分子模拟和设计(目标2)、先进材料开发(目标3)、光谱、散射和分子相互作用(目标4)、过程建模和优化(目标5)以及实验室规模分离系统的设计和实施(目标6)。使用经过验证的实验方法，该团队将测量设计萃取蒸馏、吸收或膜过程所需的热物理性质和汽液平衡。高通量分子动力学和蒙特卡罗模拟将用于计算大量制冷剂-IL体系的溶解度(相平衡)、选择性和输运性质，并通过实验验证分子力场。将合成含氟离子的新型离子液体，以探索连接制冷剂和离子液体的“化学”空间。该团队将利用一系列技术来确定制冷剂与IL的相互作用，这些技术包括：用于测量自扩散的脉冲梯度自旋回波(PG-SE)核磁共振实验、用于研究分子间相互作用的核Overhauser效应(NOE)实验、用于提供液体结构因子S(Q)的同步加速器X射线散射实验、径向对分布函数g(R)的傅里叶正弦逆变换以及动态特定长度尺度的准弹性中子散射(QENS)。在这项工作中设计的新型ILS的有效性将通过设计优化和一系列萃取蒸馏、吸收和膜分离过程的模拟和实验来展示。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。

This EFRI DCHEM Distributed Chemical Manufacturing Project, named EARTH (Environmentally Applied Research Towards Hydrofluorocarbons), will use high-fidelity experiments, advanced computer simulations, and rigorous analytical methods in a coordinated framework to discover, synthesize, and test a new type of fluid called an ionic liquid that can be used to separate, recycle, and convert high global warming potential (GWP) refrigerant mixtures into safe products. The research will be conducted by a team of researchers located at the University of Kansas, the University of Notre Dame, Texas A&M University, and Rutgers University in collaboration Brookhaven National Lab, Oak Ridge National Lab and the National Institute of Standards and Technology and two industry partners (Chemours and Iolitec). The technical, economic, and environmental impacts of the project are considerable, given the large inventory of high GWP refrigerants that must be removed from the market. The market for recycling refrigerants is valued at more than a billion dollars and preventing the release of high-GWP refrigerants into the Earth’s atmosphere is equivalent to eliminating 175 million metric tons of CO2 (or annual emissions from 50 million cars). The project has the potential to economically benefit the refrigerants business and provide a distributed chemical manufacturing process for over 100 EPA certified recyclers in the U.S. A multi-faceted strategy will be employed to maximize dissemination and knowledge sharing with the broader scientific community. The four lead institutions are committed to providing a safe and inclusive environment and will recruit five PhD students, one post-doctoral researcher, and eight undergraduates. These researchers will be provided with cross-disciplinary training in science and engineering, attend STEM workshops and safety meetings, and intern in partnering universities, companies, and national labs.This project will provide the fundamental knowledge and innovation required to recycle and repurpose high-GWP refrigerants. The project is built upon the tunable solvation properties of ionic liquids (ILs) to realize the separation of azeotropic HFC mixtures that are not possible with other materials. The two primary goals are (1) designing chemical separations with high selectivity and capacity for complex systems and (2) understanding temporal changes that occur in chemical separation systems. Six fundamental aims will integrate property measurements and equation of state modeling (Aim 1), molecular simulations and design (Aim 2), advanced materials development (Aim 3), spectroscopy, scattering, and molecular interactions (Aim 4), process modeling and optimization (Aim 5), and design and implementation of lab-scale separation systems (Aim 6). Using proven experimental methods, the team will measure the thermophysical properties and vapor-liquid-equilibria required for designing an extractive distillation, absorption, or membrane process. High-throughput molecular dynamics and Monte Carlo simulations will be used to calculate the solubility (phase equilibrium), selectivity, and transport properties of a large number of refrigerant-IL systems using molecular force fields validated by experiment. New ILs with fluorinated ions will be synthesized to explore the “chemical” space connecting refrigerants and ILs. The team will utilize a number of techniques to determine refrigerant-IL interactions including: pulse-gradient-spin-echo (PG-SE) NMR experiments for measuring self-diffusion, nuclear Overhauser effect (NOE) experiments for studying intermolecular interactions, synchrotron X-ray scattering experiments for providing liquid structure factor S(Q), inverse Fourier sine transform for radial pair distribution function g(r), and quasi-elastic neutron scattering (QENS) for dynamical specific length scales as examples. The efficacy of the novel ILs designed in this work will be demonstrated via design optimization and a set of simulations and experiments for extractive distillation, absorption, and membrane separation processes.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.