Synthesis and CO2 adsorption performance of TEPA-loaded cellulose whisker/silica composite aerogel

The CO2 storage technology of abandoned coal mines has problems such as high gas separation costs and incomplete CO2 separation in the gas capture stage, which hinders the development of abandoned coal mines for CO2 storage. Regarding the issue above, a new type of carbon dioxide adsorption material has been prepared. Cellulose whiskers/silica composite aerogels were synthesized from skim cotton using tetraethyl orthosilicate (TEOs) and alkaline silica solution as silica precursors through a sol-gel process. The obtained aerogel has a rich porous structure with a specific surface area in the range of 34.7–170.1 m2/g, pore volume in the range of 0.06–1.52 cm3/g, and average pore size in the range of 4.5–11.9 nm. The sample CSA-TEPA-70% showed excellent adsorption performance, with a maximum adsorption capacity of 2.25 mmol/g. The Avrami fractional-order kinetic model can fit the CO2 adsorption process of the adsorbent well. This adsorbent has broad prospects in the CO2 capture process.