Abstract

In this work, the performance of N-(3-trimethoxysilylpropyl)diethylenetriamine (DAEAPTS)-grafted mesoporous SBA-15 adsorbent for postcombustion carbon capture was studied. Wet grafting technique was adopted to functionalize SBA-15 surface. The adsorption of CO2 on the amine-grafted sorbent was measured by the thermogravimetric method over a CO2 partial pressure range of 0–90 kPa and a temperature range of 25–105°C under atmospheric pressure. The optimal amine loaded SBA-15 adsorbent containing 40 wt% DAEAPTS exhibited capture capacity up to 2.3 mmol/g under simulated gas conditions (88.2% CO2/N2) at 75°C. The CO2 adsorption–desorption kinetics of the grafted sorbents were found to be sufficiently fast in both dry and humid CO2 streams and it was observed that the grafted adsorbent achieved 75% of the total capacity in 5 min of adsorption time in dry 8.8% CO2/N2 and in less than 3.5 min in humid 8.8% CO2/N2. It was also observed that 95% of the total desorption occurred in less than 7 min at 150°C under pure N2. The grafted sorbents showed good reversibility and multicycle stability and the drop in capacity after 100 cycles in dry and humid 8.8% CO2/N2 streams was around 7.09% and 11.65%, respectively.