Mixed amine-modified MCM-41 sorbents for CO2 capture

A CO2 sorbent was prepared by immobilizing a mixture of tetraethylenepentamine (TEPA) and 2-amino-2-methyl-l-propanol (AMP) onto MCM-41. The prepared composites were characterized by N2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) techniques. CO2 adsorption-desorption experiments were conducted in a self-assembled fixed bed reactor under the simulated flue gas component of 15 vol.% CO2/85 vol.% N2. The promoting effects of AMP on the adsorption performance and amine efficiency of TEPA modified MCM-41 were studied. In addition, the effects of the adsorption temperature and the feed flow rate on the CO2 adsorption process were investigated. Further, the regenerability of the sorbent was studied by performing fifteen adsorption-desorption cycles over the temperature range of 70 °C (adsorption) to 100 °C (desorption). Among the prepared sorbents, MCM-41 modified with 30 wt.% TEPA and 30 wt.% AMP (MCM-41-TEPA30%-AMP30%) showed rapid adsorption kinetics and the maximum CO2 adsorption capacity of 3.01 mmol-CO2/g-sorbent at 70 °C. Moreover, the MCM-41-TEPA30%-AMP30% sorbent exhibited good regenerability and thermal stability. The results demonstrate that the MCM-41-TEPA30%-AMP30% sorbent is a promising CO2 sorbent.