CO2 chemisorption and cyclability analyses in α−Li5AlO4: effects of Na2CO3 and K2CO3 addition

Abstract

AbstractLithium aluminate (α−Li5AlO4) was synthesized and mixed with potassium carbonate or sodium carbonate. The addition of these alkaline carbonates was produced during or after the synthesis process. The CO2 chemisorption was evaluated using dynamic, isothermal, and cyclic thermogravimetric analyses. The presence of the K or Na in α−Li5AlO4 changes the sorption properties in a wide temperature range. K‐ and Na‐Li5AlO4 samples, when the alkaline carbonates were added 10 wt% presented better CO2 capture properties, capturing 37−39 wt% at 660 °C and ∼50 wt% at 710 °C, for doped samples prepared mechanically or synthetically, respectively. The results revealed that the weight gained on α−Li5AlO4 mixed with K‐ or Na‐carbonates was attributed to the formation of the eutectic phases. These materials would be suitable for CO2 capture over a wide temperature range depending on the application process. Nevertheless, the cyclic experiments showed important variations in their respective efficiencies, depending on the temperature. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd