In a new study published in the Engineering Journal, pelletisation routes for magnetic framework composites (MFCs) have shown promise for CO₂ capture.

While current research in the field has focussed on dry powder MFCs, in the study carried out at Nottingham University, MFC powders were processed into pellets through a paste extrusion method with various polymer binders. By embedding magnetic nanoparticles (MNPs) in metal–organic frameworks (MOFs), researchers were able to overcome the low thermal conductivity barriers of MOFs and facilitate the use of magnetic induction heating for thermal regeneration.

MFCs were first produced via an innovative continuous flow synthesis with multiple concentrations of magnetic nanoparticles. Surface area and CO₂ capacity losses caused by pelletisation were minimised using a low-pressure extruder, with some binders showing zero pore blocking effects. Pellet mechanical strength was increased by 107% (crushing load) and 87% (elastic modulus) from formulating with just 4% polyvinyl alcohol binder.

The researchers also investigated the thermal properties of MFCs, essential for modelling the materials’ behaviours in packed bed absorbers. Notably, thermal conductivity increased by 47% with 7.8% MNPs in the MFCs, compared to the pristine MOF, highly beneficial for applications requiring thermal cycling.

The formulation and pelletisation methods explored are applicable to a range of MOFs and MFCs, facilitating the shaping of these materials for positive impact across CO₂ capture and other applications.

Download the paper here.