CO₂ capture by amine-modified materials, tailored for enhanced adsorption capacity and selectivity

We have modified zeolite Na-Y (Si/Al = 2.55) with triethylenetetramine (TETA), using a wet-impregnation method, with the aim of synthesising a hybrid material with enhanced CO₂ adsorption capacity and selectivity, in the presence of water vapour. The dynamic adsorption capacity of CO₂ on NaY-TETA, prepared with varying loadings of amine, was examined. Following modification, the surface properties of the adsorbent were changed, as evident by examining the adsorption and desorption isotherms of CO₂ from wet gas streams. The modified materials display excellent CO₂ uptake under humid conditions. A mechanism describing the interaction of CO₂ on the surface suggests a transformation from a mainly physical to chemical bonding due to modification of the surface functional groups on TETA. In addition, multicyclic use of NaY-TETA suggests that it could be an ideal sorbent for CO₂ capture from flue gases.