Polyethylenimine-Magadiite\nLayered Silicate Sorbent\nfor CO₂ Capture

Abstract

This\npaper describes the preparation of a Layered Silicate Sorbent\n(LSS) for CO₂ capture using the layered silicate magadiite\nand organo-magadiite modified with polyethylenimine (PEI). The sorbents\nwere characterized and revealed the presence of PEI as well as its\ninteraction with CO₂ at low temperatures. The thermal stability\nof sorbents was confirmed by thermogravimetry experiments, and the\nadsorption capacity was evaluated by CO₂-TPD experiments.\nTwo kinds of PEI are present in the sorbent, one exposed PEI layer\nthat is responsible for higher CO₂ adsorption because its\nsites are external and another one, bulky PEI, capable of low CO₂ adsorption due to the internal position of sites. The contribution\nof the exposed PEI layer may be increased by a previous exchange of\nCTA⁺, but the presence of the surfactant decreased the\ntotal adsorption capacity. MAG-PEI25 reached a maximum adsorption\ncapacity of 6.11 mmol g^–1 at 75 °C for 3 h\nof adsorption and showed a kinetic desorption of around 15 min at\n150 °C.