With support from the Chemical Measurement and Imaging Program in the Division of Chemistry and the Chemical and Biological Separations Program in the Engineering Division of Chemical, Bioengineering, Environmental, and Transport Systems (CBET), Ms Kristin Chin, Dr. Catherine T. Hunt (Dow Chemical Company) and Prof. Mamadou S. Diallo (Caltech and KAIST) will be co-organizing a 1-day symposium at the fall ACS annual meeting in 2012. The symposium is titled "Ensuring the Sustainability of Critical Materials and Alternatives: Addressing the Fundamental Challenges in Separation Science and Engineering". The aims of the symposium are to: 1. Discuss the issues related to stresses in the global market and the key and enabling role of SSE in ensuring a sustainable supply and utilization of critical materials; 2. Bring into focus crosscutting research needs and Scientific Grand Challenges in SSE associated with the sustainable extraction, recovery, recycling and purification of critical materials; and 3. Communicate these research needs to the SSE and broader science/engineering community. In addition to the organized talks and panel discussion during the symposium, the symposium content will be summarized in a comprehensive report and a dedicated new website will be set up for permanent dissemination of symposium materials.
Recent stresses in the global market of rare earth elements have brought the sustainable supply of critical materials to the forefront in the United States and other industrialized countries. In addition to rare earth elements (e.g. neodymium, terbium, dysprosium and ytterbium) and platinum group metals (e.g. platinum, palladium, rhodium, ruthenium, iridium, and osmium), significant amounts of copper, silver, gold, manganese, lithium, titanium and gallium will be needed to build the sustainable products, processes, and industries of the 21st century. During the last 2 years, the supply/utilization of critical materials in renewable energy technologies has been discussed in numerous symposia, reports and publications. However, no focused symposium and in-depth report have been devoted to the role of separations science and engineering (SSE) in the areas of sustainable extraction, recovery, and recycling, as well as potential replacements of critical metals with earth-abundant elements. Thus, we proposed to organize a 1-day symposium devoted to "Ensuring the Sustainability of Critical Materials and Alternatives: Addressing the Fundamental Challenges in Separation Science and Engineering", jointly sponsored by the American Institute of Chemical Engineers (AIChE) and the American Chemistry Society (ACS). During the symposium, the discussion was organized around two major themes: 1) R&D and technology needs and 2) education and training of the future workforce in the field of separations sciences and engineering (SSE) as it applies to critical materials. Key findings from the symposium include: SSE is a broad discipline that integrates basic scientific and engineering knowledge from many fields including: (i) analytical, physical, inorganic, polymer and supramolecular chemistry, (ii) chemical engineering (e.g. equilibrium thermodynamics and transport phenomena), (iii) mining and materials engineering (e.g. mineral processing and extractive metallurgy), and (iv) process and systems engineering. In the area of separation materials, there is a critical need to design and synthesize robust, recyclable supramolecular hosts that are capable of selectively extracting critical materials from complex, heterogeneous media that can be highly corrosive and damaging to many available materials. They must be capable of seamless integration with existing separations equipment to be economically viable. In the area of separation systems, there is a need for stronger collaborations between chemical engineers and chemists as to better understand the underlying physical and chemical processes that effect design and scale up of separation processes and systems for critical materials. Not all bench-scale processes can be easily scaled up due to technical and economic viability issues. Synthetic membranes have become the critical components of a broad range of sustainability applications including: (i) energy generation, conversion and storage (e.g. fuel cells and batteries), (ii) water purification (e.g. desalination and water reuse), and (iii) chemical and biological separations (e.g. gas purification and protein separations). However, the utilization of membrane technology in the extraction, recovery and purification of critical materials from solutions (e.g. mining leach liquors and industrial wastewater) has received limited attention to date. Thus, there is a need for fundamental research in the development of new membranes (e.g. nanofiltration and affinity membranes) for use in the extraction, concentration and purification of critical materials including rare earth elements (REEs) and platinum group metals (PGMs). To achieve materials sustainability in clean and renewable energy technologies (e.g. solar photovoltaic cells, wind turbines and electrical vehicles), there is a great need to find alternatives to REEs and PGMs based on earth abundant elements. Breakthrough chemistry and advanced engineering will be necessary to develop alternatives to REEs. The search for alternatives is particularly acute, as supply and demand curves are rapidly approaching unity for such REEs as neodymium (used in the production of wind turbines). Currently, the education curriculum in separations science and technology is highly fragmented with students getting educated/trained in different versions/flavors of SEE depending on their major field of studies. There is a great need for a new and more unified education curriculum in SEE that integrates basic knowledge of the principles of separations science (e.g. thermodynamics and transport phenomena) and materials (e.g. supramolecular hosts, media and membranes) with engineering knowledge (e.g. unit operations and process/system design) and discussion of the applications of SEE to the global sustainability challenges in energy, water, food, chemicals, materials, clean environment and global climate change. More specific recommendations are given below: Science and engineering curricula needs to comprehensively integrate and emphasize separations science with a focus on sustainability-related applications Science and engineering faculty need to be better prepared to teach "green" courses that are being requested by students. Today’s generation of chemists and engineers focuses much more on "green" economics and sustainability A potential way to get students excited about separation sciences is to illustrate its critical role in the solution of societal challenges in energy, water, food, materials, environment and climate
