It is difficult to provide an exact number for the total energy that is used by all separation processes. The best guesses associate 10-15% of the total global energy consumption with separations. Given the expected increase in population and the possibility of large-scale carbon capture and storage, this amount is expected to increase significantly. Reducing the total energy costs of separations would be a major contribution in reducing our energy consumption. Developing novel materials and concepts for the efficient separation of gas mixtures is the focus of our Center for Gas Separations (CGS).
The aim of the CGS is to develop synthesis strategies to tailor-make novel materials for gas separations that are based on a fundamental understanding of materials properties and molecular interactions. Developing the science to tailor-make materials in which “every atom is at exactly the right place” to separate gases addresses one the Grand Challenges, specifically “How Do We Design and Perfect Atom- and Energy-Efficient Syntheses of Revolutionary New Forms of Matter with Tailored Properties?” as described in the report “Directing Matter and Energy: Five Chal-lenges for Science and the Imagination.” The focus of a key portion of our research will be the development of materials for carbon capture, and as such we directly address the use-inspired priority direction “Basic Research Needs for Carbon Capture: Beyond 2020.” In addition, the development of efficient gas separations could play a key role in the production of hydrogen from natural gas or renewable energy sources (Hydrogen Economy) and in the conversion of CO2 into fuels using sunlight (Solar Energy Utilization).
In the first phase of the Center, we have developed a computational method for rapidly screening millions of materials for optimal performance in carbon dioxide capture. For example, out of the millions of different metal-organic frameworks (MOFs) that can potentially be used for gas separations, in practice we can only synthesize and test a relatively small subset of these. Therefore a key aspect of the CGS was to develop computational techniques that can identify a subset of the most promising materials. In the renewal of our Center, we aim to continue this line of research, as it is exactly in line with the type of research that is proposed in “Computational Materials Science and Chemistry: Accelerating Discovery and Innovation through Simulation-Based Engineering and Science.”
One of the key challenges we face is the ability to tune the morphology and crystal size of a MOF. We lack a fundamental understanding of how these materials are formed. For example, in synthesizing membranes it is essential to control the assembly of these materials. In the renewed program, we propose to study the formation of MOFs, a topic that nicely fits in the research theme “Directing Assembly of Hierarchical Functional Materials” as described in the report “From Quanta to the Continuum: Opportunities for Mesoscale Science.”