Adsorption of carbon dioxide by a novel amine impregnated ZSM-5/KIT-6 composite

Abstract

A novel amine modified composite was fabricated for CO₂ capture. Tetraethylenepentamine (TEPA) or polyethyleneimine (PEI) was selected to modify the micro/mesoporous ZSM-5/KIT-6 composite (ZK). With the porous nature of the support, large amine loadings from 50 to 80% were expected via a typical impregnation step. The CO₂ adsorption performance was investigated by thermal gravimetric analysis (TGA) in mixed gases (15% CO₂ and the balance is N₂) at 30–90 °C. With higher nitrogen content and better texture properties (surface area and total pore volume), TEPA-loaded materials exhibited better adsorption capacities than PEI-loaded materials. In the two series of samples, ZK-TEPA-60 and ZK-PEI-60 displayed outstanding CO₂ capture, with capacities as high as 5.32 and 4.59 mmol g⁻¹ at 60 and 75 °C, respectively. ZK-TEPA-60 demonstrated relatively rapid kinetics and a higher enthalpy. The materials we designed displayed excellent CO₂ adsorption performance in comparison with other amine modified solid materials, indicating the prospects of these adsorbents for CO₂ capture from flue gas.