The amine-based postcombustion
CO2 capture (PCC) process
involves absorption of CO2 into a solvent and then regenerating
the solvent to produce CO2. In this study, the effect of
an activated carbon (AC) catalyst, synthesized through hydrothermal
treatment and furnace activation on CO2 absorption in a
4M BEA/AMP amine blend, was evaluated and compared with that of a
KMgO/CNTs (1:4) catalyst. The physical and chemical properties of
AC were investigated with a scanning electron microscope (SEM), CO2 temperature-programmed desorption (CO2-TPD), Brunauer–Emmett–Teller
(BET), powder X-ray diffraction (XRD), and thermogravimetric analyzer
(TGA) and compared with the KMgO/CNTs (1:4) catalyst. The results
showed that when compared against noncatalytic CO2 absorption,
AC enhanced the linear rate of CO2 absorption by 33.3%,
while for KMgO/CNTs, it was reported as 25.5%. The relatively higher
surface area, combined with the higher number and strength of basic
sites of AC relative to the KMgO/CNTs (1:4) catalyst, provided effective
basic reaction sites for CO2 absorption, thereby enhancing
the rate of CO2 absorption into the amine. AC was also
relatively easier to synthesize which would provide a good replacement
for the CNT-based catalyst which has carcinogenic tendencies.