Impregnation of Polyethylenimine in Mesoporous Multilamellar Silica Vesicles for CO2 Capture: A Kinetic Study
journal contributionposted on 27.04.2016, 00:00 by Lihuo Zhang, Ni Zhan, Qing Jin, Honglai Liu, Jun Hu
Amine-impregnated solid sorbents have been approved as one of the promising sorbents for CO2 capture. However, the low adsorption rate seriously limits their real application. Herein, we synthesized the mesoporous multilamellar silica vesicle (MMSV) and used them as a novel support for the impregnation of polyethylenimine (PEI). The mesoporous multilamellar structure, as well as the presence of surfactant templates, significantly improved the dispersion of PEI in sorbents and hence improved both adsorption capacity and adsorption rate simultaneously. Among various MMSV-PEIs samples, MMSV(a)-PEI-60% showed the best CO2 adsorption capacity, up to 4.73 mmol/g in pure and dry CO2 flow at 90 °C, and even exhibited a 22% enhancement in humid CO2 flow at 75 °C. Moreover, it also presented good adsorption/desorption cyclic performance. The kinetic study showed that the second-order kinetic model fitted quite well for dynamic CO2 adsorption, and the adsorption rate constants revealed its faster adsorption rate and higher amine efficiency compared with most reported amine-impregnated sorbents.