Efficient selection and reversible adsorption of sulfur dioxide by methylated polyethylenimide supported by porous carbon microspheres

Solid-supported materials are extensively utilized for SO 2 capture. Polytertiary amine compounds, which are abundant in tertiary amine groups, efficiently capture SO 2 . In this study, we propose the loading of methylated polyethylenimide (mPEI), which is rich in tertiary amine groups, into chitin-derived carbon microspheres (NCMs), which have a robust pore structure and large surface area. The produced adsorbent (mPEI@NCMs) showed good performance for capturing SO 2 . Further, the adsorption capacity of mPEI@NCMs for SO 2 at 25 °C and 1 bar was 12.23–18.12 mmol/g, whereas at 25 °C and 0.01 bar, it was 4.58–6.96 mmol/g. The mPEI@NCMs sample showed good selectivity for adsorbing SO 2 from mixtures containing N 2 and CO 2 . Furthermore, mPEI@NCMs showed a good reversible adsorption capacity for SO 2 .