resumo
Ion-exchange on bare commercial zeolites can offer improved adsorption processes. In the context of CO2/N-2 separation for post-combustion CO2 capture (PCC), here, we report, the effect of ion-exchange on commercial binder-free NaY zeolite with alkali (K+) and alkaline earth (Ca2+) metal cations, achieving exchange levels of 23 %, 58 %, and 95 % for K+ and 56 % and 71 % for Ca2+. Adsorption isotherms of CO2 and N-2 were measured over a temperature range of 306-344 K and pressures up to 350 kPa. At low pressures, the CO2 adsorption capacity increases as Na+ ions are exchanged to a higher level of K+, while a reverse trend is observed for Ca2+ exchange. At 25 kPa and 306 K, the CO2 loading (mol center dot kg(-1)) follows the order 2.01-Ca(71)Y < 2.63-Ca(56)Y < 4.05-NaY < 4.29-K(23)Y < 4.59-K(58)Y < 4.72-K(95)Y. The selectivities of CO2 (15 %)/N-2 (85 %) at 306 K and 101.3 kPa range from 52 for Ca(71)Y to 101 for K(23)Y, compared to 89 in the bare NaY zeolite. The working capacities for the most promising exchanged sample (K(23)Y) exhibit superior values of 4.51, 2.98, and 2.41 mol center dot kg(-1) considering regeneration pressures of 3, 10, and 15 kPa, relative to a feed pressure of 101.3 kPa, respectively. Dynamic simulations were conducted using the Aspen Adsorption package to accurately predict both single- and binary-component breakthrough curves.
palavras-chave
CARBON-DIOXIDE CAPTURE; SWING ADSORPTION; FLUE-GAS; ADSORBENT; VACUUM; 13X; EQUILIBRIUM; SORPTION; CATIONS; OPTIMIZATION
categoria
Engineering
autores
Aly, E; Zafanelli, LFAS; Henrique, A; Gleichmann, K; Rodrigues, AE; Freitas, FAD; Silva, JAC
Grupos
Projectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work was supported by national funds through FCT/MCTES (PIDDAC): (1) project PTDC/EQU-EPQ/0467/2020 (DOI:10.54499/PTDC/EQU-EPQ/0467/2020) ; (2) CIMO, UIDB/00690/2020 (DOI: 10.54499/UIDB/00690/2020) and SusTEC, LA/P/0007/2020 (DOI: 10.54499/LA/P/0007/2020) ; (3) CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020 & LA/P/0006/2020.