Premium
Amine‐Tethered Solid Adsorbents Coupling High Adsorption Capacity and Regenerability for CO 2 Capture From Ambient Air
Author(s) -
Choi Sunho,
Gray McMahan L.,
Jones Christopher W.
Publication year - 2011
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201000355
Subject(s) - adsorption , thermogravimetric analysis , sorbent , thermal stability , chemical engineering , materials science , desorption , fourier transform infrared spectroscopy , chemistry , organic chemistry , engineering
Silica supported poly(ethyleneimine) (PEI) materials are prepared via impregnation and demonstrated to be promising adsorbents for CO 2 capture from ultra‐dilute gas streams such as ambient air. A prototypical class 1 adsorbent, containing 45 wt % PEI (PEI/silica), and two new modified PEI‐based aminosilica adsorbents, derived from PEI modified with 3‐aminopropyltrimethoxysilane (A‐PEI/silica) or tetraethyl orthotitanate (T‐PEI/silica), are prepared and characterized by using thermogravimetric analysis and FTIR spectroscopy. The modifiers are shown to enhance the thermal stability of the polymer‐oxide composites, leading to higher PEI decomposition temperatures. The modified adsorbents present extremely high CO 2 adsorption capacities under conditions simulating ambient air (400 ppm CO 2 in inert gas), exceeding 2 mol CO 2 kg sorbent −1 , as well as enhanced adsorption kinetics compared to conventional class 1 sorbents. The new adsorbents show excellent stability in cyclic adsorption–desorption operations, even under dry conditions in which aminosilica adsorbents are known to lose capacity due to urea formation. Thus, the adsorbents of this type can be considered promising materials for the direct capture of CO 2 from ultra‐dilute gas streams such as ambient air.