Reversible adsorption of carbon dioxide on amine surface-bonded silica gel

Carbon dioxide adsorbs reversibly on a silica gel containing 3-aminopropyl groups bonded to surface atoms of silicon. These act as the active sites for the chemisorption of CO2 at room temperature which is liberated by temperature programmed desorption at about 100 degrees C. The material is capable of adsorbing about 10 STP cm(3) of dry CO2 per gram and can be regenerated upon heating. It might be used as scrubber for carbon dioxide from industrial gaseous streams. Adsorption of humid CO2 produces a small amount of formaldehyde which suggests activation of the carbon dioxide molecule.