Mesoporous Carbon-Supported Solid Amine Sorbents for Low-Temperature Carbon Dioxide Capture

Abstract

A novel solid amine sorbent has been developed based on polyethylenimine (PEI)-impregnated mesoporous carbon (MC) supports for regenerative removal of pure CO2 at low temperature. The adequate pore volume, proper pore size, and interconnected 3D framework of as-prepared MC allow the easy dispersion and immobilization of PEI within their channels. The structure generates considerable gas/amine interfacial area and provides access to fast CO2 diffusion for reactivity with the amine groups. In addition, the kinetic inhibition of CO2 diffusion within the PEI films could be alleviated by the introduction of polymer-based surfactant, offering an increased number of reactive sites and higher utilization efficiency of amine groups. Owing to the advanced support and facilitating kinetic diffusion, as-prepared MC-based solid amines display outstanding sorption features for CO2 capture at low-temperature range. The highest sorption capacities of 4.67 mmol·g–1 at 30 °C and 2.80 mmol·g–1 at 0 °C for pure CO2 are attained. They also show fast kinetics, a good selectivity for CO2/N2 separation, and very reversible and durable CO2 capturing performance at low temperature. All the results suggest that MC-based solid amine sorbent is a promising CO2 sorbent to meet the challenges of the current CO2 capture and storage technology.