Density and N2O solubility of sodium and potassium carbonate solutions in the temperature range 25 to 80 °C

To deduce kinetic parameters for the reactions of carbon dioxide (CO2) in carbonate solutions the physical solubility of CO2 into the reacting solution is needed. To measure the physical solubility directly with CO2 is not possible, so the solubility of nitrous oxide (N2O) is normally measured instead. The physical solubility of CO2 can then be calculated based on the solubility of CO2 and N2O into water and the solubility of N2O in the solution of interest invoking the so called N2O analogy (Clarke, 1964; Laddha et al., 1981). To obtain good accuracy of the solubility measurements the accurate density of the solution is needed. In this study the densities were measured with pycnometers up to 353 K.In this paper the parameters in the model of Weisenberger and Schumpe (1996) were refitted specifically for the two carbonate systems using experimental data up to 353 K and up to 30 wt% (3.7 kmol/m3) aqueous sodium carbonate and up to 50 wt% (5.5 kmol/m3) aqueous potassium carbonate solutions.