3D-printed activated carbon for post-combustion CO2 capture

Abstract

The applicability of 3D-printed activated carbons for their use to CO 2 capture in post-combustion streams and the influence of activation conditions on CO 2 uptake and CO 2 to N 2 selectivity were studied. For two monoliths with the same open cellular foam geometry but low and high burnoff during activation, a series of fixed-bed breakthrough adsorption experiments under typical post-combustion conditions, in a wide range of temperature (313 and 373 K), and partial pressure of CO 2 up to 120 kPa were carried out. It is shown that the higher burnoff during activation of the 3D printed carbon enhances the adsorption capacity of CO 2 and N 2 due to the increased specific surface area with sorption uptakes that can reach 3.17 mol/kg at 313 K and 120 kPa. Nevertheless, the lower burnoff time on monolith 1 leads to higher selectivity of CO 2 over N 2 , up to 18 against 10 on monolith 2, considering a binary interaction to a mixture of CO 2 /N 2 (15/85 vol%) at 313 K. The single and multicomponent adsorption equilibrium is conveniently described through the dual-site Langmuir isotherm model, while the breakthrough curves simulated using a dynamic fixed-bed adsorption linear driving force model. Working capacities for the 3D printed carbon with lower burnoff time lead to the best results, varying of 0.15–1.1 mol/kg for the regeneration temperature 300–390 K. Finally, consecutive adsorption-desorption experiments show excellent stability and regenerability for both 3D printed activated carbon monoliths and the whole study underpins the high potential of these materials for CO 2 capture in post-combustion streams. • Printed activated carbon monoliths were developed as adsorbents for CO 2 capture. • Thermal treatment affects the selectivity of CO 2 over N 2 on the monoliths. • CO 2 working capacity on the monolith M1 is 17% higher than monolith M2. • 3D-printed monoliths show high stability and regenerability over consecutive cycles. • A mathematical model has been developed for process simulation to CO 2 capture.