Vapor-liquid equilibria of the carbon dioxide loaded sodium carbonate-water system were measured in the temperature range 40-80 degrees C and for sodium carbonate concentrations 8-12 wt%. In addition the vapor pressure of water over 10-30 wt% sodium carbonate solutions for the temperature range 27-100 degrees C was measured in an ebulliometer. The system was modeled using the electrolyte-NRTL model. Experimental vapor-liquid data from this study as well as data available in the literature from 25 to 195 degrees C and for sodium carbonate concentrations from 0.5 to 12 wt% were used for parameter fitting. The average deviation of the model predictions compared to all experimental data found is 9.8% for the partial pressure of CO2. For vapor pressure of water the standard deviation is 0.6% up to 100 degrees C and 30 wt% sodium carbonate solutions. (C) 2009 Elsevier Ltd. All rights reserved.