Input on the Measurement and Comprehension of CO 2 Solubility in Molten Alkali Carbonates in View of Its Valorization

As the capture and valorization of CO 2 in molten carbonates is nowadays becoming a strategic energy topic, the need of accurate solubility measurements of such molecule is becoming compulsory. This study provides a new set of reliable CO 2 solubility values, determined by a a carefully adapted manometric setup, in Li 2 CO 3 -K 2 CO 3 (62:38 mol%), Li 2 CO 3 -Na 2 CO 3 (52:48 mol%), Li 2 CO 3 -Na 2 CO 3 -K 2 CO 3 (43.5:31.5:25.0 mol%) and Na 2 CO 3 -K 2 CO 3 (56:44 mol%) carbonate eutectics in an overall range of temperatures from 450 to 850 °C. High solubility values are obtained for Li-K and Li-Na eutectics, respectively 1.7 × 10 −1 and 1.1 × 10 −1 mol atm −1 l −1 at 650 °C. It is shown that CO 2 solubility increases with the temperature for most of the eutectic mixtures. Another important trend is that the Li content significantly increases the solubility.