Ionic liquid containing amine-based silica aerogels for CO2 capture by fixed bed adsorption

Abstract

The main goal of this study is to develop an adsorption based process using amine-based silica aerogels to capture CO2 from post-combustion gases. For this purpose, silica based aerogels were synthesized by following single-step sol-gel method using tetraethyl orthosilicate (TEOS) as silica precursor and (3-Aminopropyl)triethoxysilane (APTES) as amine source in different compositions. To enhance CO2 capture performances of the prepared aerogels, amine-containing ionic liquid (1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) was also used as sol agent due to high CO2 selectivity and lower viscosity. Chemical structural properties, thermal behaviors, surface area and morphologies of prepared aerogels were analyzed. CO2 capture performances of prepared aerogels were investigated in a fixed bed column of CO2 capture experimental set-up for adsorption. Results have shown that CO2 adsorption capacities of ionic liquid containing amine-based aerogels increased with the addition of amine source and ionic liquid. Among the prepared aerogels, the sample of TA0.24IL0.28 exhibited superior adsorption behavior with the maximum capacity of 243.32 mg CO2/g (5.53 mmol/g).