Greener carbon capture using microwave heating for the development of cellulose-based adsorbents
Simba Biti, Alan J. McCue, Davide Dionisi, Inês Graça, Claudia Fernández Martín
Abstract
In this work, CO 2 -activated carbons were produced from microcrystalline cellulose using microwave heating during activation. Activations were thus completed at 400 °C to burn-offs of 10, 20 and 30 wt%. The activated carbons’ CO 2 adsorption capacity was tested over 10 cycles of adsorption (25 °C) and desorption (100 °C). CO 2 adsorption capacity was found to increase with increasing activation burn-off, whilst larger average dynamic adsorption capacities were achieved with activated carbons of 20 wt% (1.64 mmol/g) and 30 wt% (1.73 mmol/g) burn-off compared to commercial activated carbon Norit R2030CO2 (1.58 mmol/g). These microwave-prepared activated carbons were also compared with similar activated carbons produced using conventional heating in our previous work. The microwave-prepared activated carbons were found to possess 9.5–25.6 % larger CO 2 adsorption capacities at equivalent burn-offs, despite being produced at 200 °C lower temperature, 83–94 % shorter activation times and 39–68 % lower heating energy consumption. These results represent the establishing of a more efficient means of producing microcrystalline cellulose-based activated carbons for a greener, sustainable carbon capture that contributes to the circular economy.