Surfactant promoted solid amine sorbents for CO2capture

Abstract

A new strategy to improve the CO2 capture performance of solid amine sorbents has been developed based on the balance of CO2 kinetic diffusion and thermodynamic sorption. The CO2-neutral surfactant was introduced into polyethyleneimine (PEI) to create extra CO2 transfer pathways, facilitating CO2 diffusion into the deeper PEI films. Consequently, the sorbents offered increased amount of reactive sites and higher utilization efficiency of amine groups, leading to a dramatically enhanced CO2 dynamic capacity and total capacity. Due to the facilitating diffusion, the sorbents could work at room temperature with very good performance. At 30 °C the surfactant-promoted sorbents had the CO2 capture capacity as high as 142 mg g−1 and their amine utilization was over 50%, which are the highest values ever reported for the PEI loaded sorbents working at this temperature. The surfactant-promoted sorbents also exhibited much better sorption kinetics and regeneration performance. In addition to advancing the support or amine, the present study provides another cost-efficient and general approach to design high performance CO2 solid sorbents and may have a major impact on the advance of current carbon capture and storage technologies.