CO2 Capture from Air Using Amine-Functionalized Kaolin-Based Zeolites

Several inexpensive zeolites such as ZSM-5 (MFI), zeolite Y (FAU), and SAPO-34 (CHA) were developed from kaolin clay and applied for CO2 capture from air. These molecular sieves were functionalized with tetraethylenepentamine (TEPA) in order to further improve their CO2 capacity. The obtained kaolin-based zeolites exhibited similar properties than those of zeolites prepared with other sources. They also revealed a bimodal pore network consisting of both micropores and mesopores. The effect of amine loading on CO2 capture was investigated and the results demonstrated that TEPA-modified zeolite Y with 10wt% TEPA had a higher capacity than other zeolites due to its larger mesopore volume. The presence of mesopores in the zeolite Y framework facilitated a better accessibility of CO2 molecules to the amine sites.