Advancing electrified CO2 capture: Material design strategies for magnetic adsorption composites

Abstract

This study investigates the design and performance of magnetic adsorption composites (MACs) for application in electrified CO2 capture with temperature swing adsorption from point sources. The MACs were composed of Fe3O4 as magnetic component to act as inductive heating source and zeolite 13× as a CO2 adsorbent. Three MAC configurations were prepared and evaluated under temperature feedback-loop control at different desorption temperatures ranging between 100−150°C: Homogeneous mixture of Fe3O4 and zeolite 13×, a core-shell structure with magnetic Fe3O4 core and zeolite 13× shell, and a mixed bed configuration containing separate heating and adsorbent beads. Resistive wall heated and room-temperature desorption experiments were conducted as references. In average, the heating experiments reached a steady-state effective working capacity after around 20 adsorption-desorption cycles. The homogenous mixture exhibited the most favorable performance, combining fast heating response, stable temperature control, and high CO2 desorption efficiency. When reaching steady state, it achieved 99% desorption within 94s and the highest productivity of 0.52 mgCO2 / gMAC*S with a theoretical regeneration energy of 3.0 MJ/kgCO2 [Formula presented]. The core-shell structure showed limited temperature control due to low heat transfer through the shell, while the mixed bed configuration achieved moderate performance. Compared with column wall heating, inductive heating improved thermal efficiency by delivering heat directly to the adsorbent region. However, efficient coupling of the magnetic field to the magnetic material remains the key challenge for energy efficient induction heated TSA.