Exemplar Mixtures for Studying Complex Mixture Effects in Practical Chemical Separations

Abstract

Materials and processes for chemical separations must be used in complex environments to have an impact in many practical settings. Despite these complexities, much research on chemical separations has focused on idealized chemical mixtures. In this paper, we suggest that research communities for specific chemical separations should develop well-defined exemplar mixtures to bridge the gap between fundamental studies and practical applications and we provide a hierarchical framework of chemical mixtures for this purpose. We illustrate this hierarchy with examples, including CO 2 capture, capture of uranium from seawater, and separations of mixtures from electrocatalytic CO 2 reactions, among others. We conclude with four recommendations for the research community to accelerate the development of innovative separations strategies for pressing real-world challenges.

Molecular Characterization of Membrane Gas Separation under Very High Temperatures and Pressure: Single- and Mixed-Gas CO2/CH4 and CO2/N2 Permselectivities in Hybrid Networks

“…Since the ideal and real transport parameters can differ [ 13 , 56 , 62 , 63 , 118 , 119 , 120 , 121 ], the latter should be closer to the operating process if realistic compositions are being tested. In practice, even if real mixtures are usually very complex [ 1 , 52 , 57 ], tests on binary mixtures will assess the capacity of the material to separate the key target species. In this work, all the networks were first studied under N 2 , CH 4 and CO 2 single-gas conditions, which amounted to a total of 42 simulations.…”

“…While it is known that mixed-gas effects vary both with the pressure and the gas composition [ 63 ], two classical binary gas mixtures [ 1 , 141 ], i.e., CH 4 /CO 2 and N 2 /CO 2 with a ratio of 90%/10%, were examined as test cases. In the selectivities, the more permeable CO 2 is systematically “gas A”, while CH 4 or N 2 are “gas B”.…”

“…Separation processes are an essential part of the chemical industry [ 1 ]. The energy costs associated with the traditional separation techniques based on phase changes are very high and the use of more efficient methods is strongly advocated for both economical and environmental reasons [ 1 , 2 ].…”

“…Separation processes are an essential part of the chemical industry [ 1 ]. The energy costs associated with the traditional separation techniques based on phase changes are very high and the use of more efficient methods is strongly advocated for both economical and environmental reasons [ 1 , 2 ]. Non-porous polymer membranes have emerged as one of the possible alternatives, since they are able to separate small gases and vapors of similar sizes based on their differences in permeabilities [ 3 , 4 ].…”

Navigating the Future of Separation Science Education: A Perspective

“…This provides an opportunity to introduce techniques more commonly used for these macromolecules, including size exclusion chromatography and field-flow fractionation. This broader approach could also be designed to focus on applications that better bridge the analytical and engineering aspects of separation science [ 10 ]. Once identified, these examples could then be implemented into an integrated separations curriculum.…”