Abstract
Magnetic induction has emerged as an attractive method for regenerating adsorbents during separation processes. In this work, we investigated the applicability of magnetic composite sorbents comprising Fe2O3 and zeolite 13X in biogas upgrading via a magnetic induction process. The sorbent materials with 10, 15, and 20 wt % Fe2O3 content were formulated into monolithic contactors via additive manufacturing and their physiochemical and magnetic properties were assessed accordingly. The effects of Fe2O3 particle size, magnetic field intensity, and monolith composition and configuration on CO2 and CH4 desorption rates as well as heating and cooling rates were systematically investigated. Our results indicated that 5 μm-size Fe2O3 with a loading of 20 wt % in the composite is the best performing material exhibiting heating, cooling, and desorption rates of 6.56 °C/min, 3.84 °C/min, and 0.25 mmol CO2/g min, respectively. It was also found that the layer-by-layer printing approach outperforms the homogenously mixed method in formulating magnetic monoliths by exhibiting heating, cooling, and desorption rates of 7.78 °C/min, 4.89 °C/min, and 0.376 mmol CO2/g min, respectively. Lastly, the advantage of induction heating over traditional heating in quickly regenerating the adsorbent was demonstrated. This work highlights the suitability of the induction heating method in upgrading biogas as a renewable source of energy.