Integrated two-stage adsorption for selective removal of CO2 and SO2 by amine-functionalized SBA-15

A novel process for integrated two-stage selective removal of CO2 and SO2 from a simulated flue gas by an adsorption method was developed. Triethylolamine (TEA)-loaded SBA-15 was selected as the SO2 adsorbent, and tetraethylenepentamine (TEPA)-loaded SBA-15 was the CO2 adsorbent. Scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, N-2 adsorption/desorption, X-ray photoelectron spectroscopy, and X-ray diffraction techniques were used to characterize the properties of the adsorbents. The effects of the height-diameter ratio (H/D) of the adsorbent bed and operation temperature were tested for the removal of SO2. The results indicated that the pore volume and surface area of SBA-15-TEA-50 and SBA-15-TEPA-50 dropped with the increase of amine loading. SO2 breakthrough adsorption capacity of SBA-15-TEA-50 was 146.3 mg of SO2/(g of adsorbent). The integrated two-stage removal experiment of SO2 and CO2 over SBA-15-TEA and SBA-15-TEPA showed that CO2 and SO2 in gas mixture can be removed in two stages, respectively. Regeneration experiment showed that both the SO2 and CO2 breakthrough capacity almost kept a constant in the multiple cycles, and the regeneration of integrated two-stage system was stable. (C) 2017 Curtin University of Technology and John Wiley & Sons, Ltd.