NanoSep · Hybrid nanoporous materials for the separation of fluid mixtures

Hybrid nanoporous materials for the separation of fluid mixtures

Fluid separation accounts for 10-15% of the world's energy consumption. Therefore, developing better and more affordable filtration membranes as alternatives to distillation is a pressing issue. If new separation processes were applied to sectors such as petroleum, chemical, and paper manufacturing, hundreds of millions of tonnes of carbon dioxide emissions could be prevented annually. To reach that goal, a deeper understanding of the behavior of confined mixtures within multiscale porous materials is crucial for developing new and efficient fluid separation processes. Nanoporous materials have a large specific surface area, typically greater than 1000 square meters per gram, allowing them to interact strongly with fluids. This makes them an excellent choice for fluid separation applications. However, currently, only a few fluid mixtures can be separated using nanoporous materials. As a result, most large-scale fluid separation operations rely on costly thermal processes such as distillation and cryogenization. Developing new fluid separation processes based on nanoporous materials could provide cost-effective solutions to environmental and industrial challenges, such as CO2 and CH₄ emissions and water contamination. The objective of the MSCA fellowship NanoSep is to deepen our understanding of confined fluid behaviors within heterogeneous nanoporous materials and to develop new fluid separation processes based on this knowledge. Currently, the development of new separation processes is hindered by two major obstacles. First, fluid mixtures confined at the nanoscale exhibit surprising and poorly understood behaviors, such as spontaneous phase demixing or dewetting transitions, where a normally wet nanopore becomes effectively non-wettable for a specific mixture composition and geometry. Second, the porous materials that are most promising for fluid separation applications exhibit a broad variety of pore sizes and surface heterogeneities, making the analysis of confined fluid behaviors more challenging. In fact, fluids confined within heterogeneous porous materials often simultaneously display several scale-dependent properties (e.g., viscous, capillary, activated fluid transport) and phases (e.g., liquid, vapor, adsorbed), which hinder direct comparisons between experiments and theories. As a consequence, it is still unknown how the exotic behaviors of nanoconfined mixtures reflect on large-scale demixing properties, limiting the conception of new fluid separation processes that would benefit from the molecular separation phenomena exhibited by nanoconfined mixtures. If new separation processes were applied to the petroleum, chemical, and paper manufacturing sectors, hundreds of millions of tonnes of carbon dioxide emissions could be prevented every year. Therefore, the development of energy-efficient fluid separation technologies aligns with global and EU strategies for reducing industrial carbon emissions, such as the European Green Deal and the UN Sustainable Development Goals. By aiming to decrease reliance on energy-intensive distillation, this project supports the transition to a more sustainable and resource-efficient industrial sector.

Data: CORDIS, © European Union