Synthesis and characterization of a thermosensitive solid amine biomass adsorbent for carbon dioxide adsorption

A thermosensitive solid amine fiber SF-AM-co-NIPAM-HBP-NH₂ was synthesized by grafting temperature-sensitive monomer N-isopropyl acrylamide (NIPAM) as well as acrylamide (AM) onto the surface of substrate sisal fiber, and further aminating with hyperbranched amine. FTIR, ¹³C NMR, SEM, EA and TGA were used to confirm the structure and chemical properties of the grafted fibers. Swelling ratio and CO₂ adsorption-desorption experiment were investigated to verify the thermo-sensitivity of the grafted fibers and their CO₂ adsorption-desorption behavior. Compared with conventional solid amine adsorbents regenerated around 140 °C, SF-AM-co-NIPAM-HBP-NH₂ (1:1) with NIPAM could be regenerated at a much lower temperature of 60 °C, while still maintain a high CO₂ adsorption capacity (2.61 mmol/g), comparable to that of SF-AM-HBP-NH₂ (2.73 mmol/g) before NIPAM introduction. Its excellent regeneration property and the effect of energy consumption reduction make it possible to be used for CO₂ adsorption in industrial process.