Effect of amine structure on CO2 capture performance of amine-modified SBA-15

Abstract

To investigate the relative CO2 capture performance of “molecular basket” type solid amine sorbents with varying amine structural characteristics, two model amine isomers, triethylenetetramine(TETA) and tris(2-aminoethyl)-amine(TAEA), were chosen alongside mesoporous silica SBA-15 as a support. The CO2 capture performance of each amine derivative was evaluated using a breakthrough method with a fixed-bed reactor. The results show that, in the absence of moisture, the SBA-TETA sorbents show better CO2 capture performance than the SBA-TAEA sorbents; on the other hand, in the presence of moisture, the SBA-TAEA sorbents show slightly improved uptake compared to the SBA-TETA sorbents. The tertiary amine groups, such as those found on TAEA, are known to be un-reactive with CO2 in the absence of moisture, but is activated in the presence of moisture may account for these findings.