Generally, the authors are thankful to Dr. M. Rückriem and Dr. A. Schreiber from Microtrac Retsch GmbH for the kind support with nitrogen physisorption and mercury porosimetry measurements.
The authors acknowledge the joint financial support from Fundação para a Ciência e a Tecnologia (FCT), in Portugal, and the Deutscher
Akademischer Austauschdienst (DAAD), in Germany. Foundation for Science and Technology (FCT, Portugal) and ERDF under Programme PT2020 to CIMO (UIDB/00690/2020) and POCI-01-0145-FEDER006984-Associate Laboratory LSRE-LCM. Foundation for Science and Technology (FCT, Portugal) under Programme PTDC 2020 * 3599-PPCDTI * Engenharia dos Processos Químicos * project PTDC/EQU-EPQ/0467/2020. Foundation for Science and Technology (FCT, Portugal), through the individual research grants SFRH/BD/148525/2019 for Adriano Henrique and DFA/BD/7925/2020 for Lucas F. A. S. Zafanelli.
The applicability of 3D-printed activated carbons for their use to CO2 capture in post-combustion streams and the
influence of activation conditions on CO2 uptake and CO2 to N2 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 CO2 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 CO2 and N2 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 CO2 over N2, up to 18 against 10 on monolith 2,
considering a binary interaction to a mixture of CO2/N2 (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 CO2 capture in post-combustion streams.
