Alkali metal (Na, Cs and K) promoted hydrotalcites for high temperature CO2 capture from flue gas in cyclic adsorption processes

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Luis Madeira (Author) FEUP; A. Catarina Faria (Author) FEUP; R. Trujillano (Author) Other; V. Rives (Author) Other; C.V. Miguel (Author) Other; Alírio Rodrigues (Author) FEUP

Journal

Title: Chemical Engineering Journal

Vol. 427 No. 130994

Initial page: 131502

ISSN: 1385-8947

Publisher: Elsevier

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Other information

Authenticus ID: P-00V-A0M

DOI: 10.1016/j.cej.2021.131502

Abstract (EN): A hydrotalcite (HT) with a Mg2+/Al3+ molar ratio of 2 was prepared and promoted with different loadings of Na and Cs. After calcination (denoted as CHT), the samples were tested for CO2 sorption at 573 K and 0.15eg bar of CO2 (typical of flue gas). Their performance was compared to that achieved with a commercial HT, MG63, and with a K-doped material for which a significant increase of CO2 sorption capacity has been frequently reported in the literature. However, the presence of K slows down the sorption kinetics, which might compromise the cyclic separation process productivity. In this work, it is aimed to find out a CO2 HT-based sorbent with promising behaviour during continuous sorption/desorption cycles, in terms of sorption capacity, sorption kinetics and cyclic stability. The best compromise was observed for a CHT doped with 9.4 wt% of Cs. A study of the cyclic stability of this material was performed and a kinetic model that can predict the loss of sorption capacity with cycles has been successfully developed. The performance of this sorbent was further investigated in a scenario where other species found in flue gas streams (i.e. O-2, H2O and/or CO) are also present.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15