Since the industrial revolution, a sharp increase in atmospheric concentrations of the greenhouse gas carbon dioxide (CO2) has been observed from the typical 180-280 ppm to over 400 ppm. This has strongly negative implications for the environment and society, likely resulting in 250,000 additional deaths worldwide annually between 2030 and 2050.

The largest contributor to global anthropogenic CO2 emissions is coal-fired power plants (10.1 Gt in 2018, 30% of total emissions). Post-combustion CO2 capture facilities can be retrofitted into existing power stations. However, the current aqueous amine absorption technologies for this process have high energy requirements for separation and purification, increasing a power plant's energy demand by 25-40% or electricity cost by $0.06 per KWh.

Alternatives have been investigated such as physical absorbents, membranes, chemical looping and solid adsorbents, e.g. porous carbons, zeolites, alumina and metal-organic frameworks. Of these, solid adsorbents possess many advantages over other technologies such as a reduced energy for regeneration from physisorption and greater capacity and selectivity for CO2. Metal-organic frameworks are porous lattices of metal ions/clusters with organic linkers and are of particular interest due to their tuneable natures and high porosities and internal surface areas. These can result in excellent CO2 adsorption profiles, optimisable for specific flue gas conditions.

Proposed solution and methodology

Evaluating metal-organic frameworks for carbon capture applications in realistic working conditions, with consideration of industrial process design is of vital importance for their successful utilisation. This requires materials with high thermal and chemical stabilities and the development of energy-efficient processes. Magnetic framework composites contain metal-organic frameworks combined with magnetic materials and show many advantages over other materials (for example, enhanced thermal stability, simple magnetic-field induced separation, energy-efficient localised induction heating for framework synthesis or regeneration and magnetic field assisted fluidisation).

This project aims to develop novel magnetic framework composites (consisting of functionalised magnetic materials and state-of-the-art metal-organic frameworks) for CO2 capture with profiles and processing capabilities for post-combustion flue gas. Scalable and sustainable syntheses will be explored for these composites, along with their CO2 adsorption capabilities, ideally with efficient regeneration processes. Model flue gas mixtures shall be used for testing and their properties compared to alternative materials.