Amine functionalized lignin-based mesoporous cellular carbons for CO2 capture

Amine-impregnated mesoporous carbon sorbents have been considered one of the most promising sorbents for CO2 capture from streams with low CO2 concentrations. In this work, a series of novel solid amine adsorbents were prepared by impregnating polyethyleneimine (PEI) on mesoporous carbons using low-cost bio-waste material “lignin” as a carbon precursor via a facile templating method. Our results demonstrated that the mesoporous carbon with 3D interconnected porous structure and large pore size and pore volume exhibited excellent CO2 adsorption capture of 2.90–3.13 mmol/g at a temperature operating window of 75–90 °C under CO2 partial pressure of 0.15 bar, being significantly higher than PEI impregnated sorbents prepared by using mesoporous carbon with 2D porous structures and also many amine-impregnated carbon-based sorbents reported in previous studies. The well-developed 3D interconnected mesoporous structure, high pore volume (up to 1.80 cm3/g), and large pore size permit the facile dispersion and immobilization of PEI within their pores and high availability of amine groups, which significantly improves both the CO2 adsorption capacity and kinetics. In addition, the cyclic adsorption–desorption test showed that the PEI-impregnated sorbents exhibit superior thermo-stability. These results indicate that the PEI-impregnated mesoporous adsorbents are promising ideal candidates for post-combustion CO2 capture. This work provide a potential strategy to prepare advancved amine impregnanted mesoporous carbons from lignin for efficient carbon capture.