(685b) SiO2-Supported Tetraethylenepentamine and Polyethylene Glycol for CO2 Capture

The paper reports results of CO2 capture study on SiO2-supported tetraethylenepentamine (TEPA) and polyethylene glycol (PEG). PEG200 was selected for this study because of its potential to disperse TEPA via interaction between its OH and TEPA's NH2. TEPA/SiO2 and PEG/TEPA/SiO2 sorbents were prepared by impregnation method. CO2 capture capacity, adsorption mechanism, and degradation characteristics of the two sorbents were studied by Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy and Mass Spectrometry (MS). The results show that the rate of degradation in CO2 capture capacity of PEG/TEPA/SiO2 is significantly lower than that of TEPA/SiO2. Degradation of TEPA/SiO2 was found to correlate with accumulation of carboxylate species. PEG forms hydrogen bonding with NH2/NH in TEPA, slowing down the formation of carboxylate species. The optimization of PEG composition could further enhance long term stability of the sorbent.