CO2—H2O Capture and Cyclability on Sodium Cobaltate at Low Temperatures (30–80 °C): Experimental and Theoretical Analysis. Issue 3 (6th March 2019)

• Record Type: Journal Article
• Authors: Vera, Elizabeth; Duan, Yuhua; Pfeiffer, Heriberto
• Is Part Of: Energy technology. Volume 7:Issue 3(2019:Mar.)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-03-06
• Subjects: CO2 capture -- sodium cobaltate -- thermodynamic analysis; Energy development -- Periodicals; Power resources -- Periodicals; 333.79
• DOI: 10.1002/ente.201800527
• Languages: English
• ISSNs: 2194-4288

Abstract

Abstract : Sodium cobaltate (NaCoO2 ) is analyzed for the CO2 cyclic carbonation–decarbonation process at low temperatures (30–80 °C) with relative humidity (RH) values between 0% and 80%, using water vapor as a catalytic intermediate. The presence of H2 O clearly enhances the CO2 capture at T < 100 °C, compared with dry conditions, where the amount of CO2 captured increases as a function of RH. These improvements are attributed to the formation of NaHCO3 and Na2 CO3 during carbonation. In the case of NaHCO3, water vapor becomes a part of carbonation, favoring reactivity. After the carbonation analysis, the decarbonation process is analyzed using a N2 flow, where results evidence that only NaHCO3 decomposition takes place at low temperatures, producing NaOH and CO2 . This result indicates that NaCoO2 can be partially regenerated, suggesting a possible CO2 cyclic carbonation. CO2 carbonation–decarbonation tests are performed, confirming the cyclic capacity and stability. Moreover, the NaCoO2 sample is modified by adding different transition metals (Fe, Cu, and Ni) to improve CO2 —H2 O sorption under similar physicochemical conditions. Results indicate that Fe‐containing samples present the best properties. Finally, the effect of CO2 partial pressure on NaCoO2 and Fe‐containing samples is analyzed using similar RHs. Abstract : Sodium cobaltate is tested for the CO2 cyclic carbonation–decarbonation process at low temperatures, where water vapor acts as a catalytic intermediate species. H2 O(v) enhances CO2 capture at T < 100 °C, and it is attributed to the formation of NaHCO3 and Na2 CO3 during the carbonation process. In the case of NaHCO3, H2 O(v) becomes a part of carbonation.