Surfactant promoted solid amine sorbents for CO2 capture

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.