Supercritical drying: A promising technique on synthesis of sorbent for CO₂ capture

The objective of this paper is to present a new technique, supercritical drying (SCD), for CO₂ capture, utilisation and storage (CCUS). To investigate the effect of drying methods on the structure and CO₂ capture performance of an aerogel sorbent, amine hybrid silica aerogel (AHSA) was prepared by SCD and ambient pressure drying (APD). The characterisation results of N2 adsorption/desorption, scanning electron microscopy and X-ray photoelectron spectroscopy measurements demonstrate that the pore structure and surface amine content of the sorbent are significantly improved because of the use of SCD. The CO₂ adsorption capacities of AHSA dried by SCD are much higher than that of AHSA dried by APD. The CO₂ adsorption kinetics of the adsorbent under different conditions was also investigated. The results reveal that the sorbent preparation method is inspiring and its resulting sorbent is dynamic in low-concentration CO₂ capture.