Micro-encapsulated Carbon Sorbents (MECS) are a new class of carbon capture materials consisting of a CO2- absorbing liquid solvent contained within solid, CO2-permeable, polymer shells. MECS enhance the rate of CO2 absorption for solvents with slow kinetics and prevent solid precipitates from scaling and fouling equipment, two factors that have previously limited the use of sodium carbonate solution for carbon capture. Here, we examine the thermodynamics of sodium carbonate slurries for carbon capture. We model the vapour-liquid-solid equilibria of sodium carbonate and find several features that can contribute to an energy-efficient capture process: very high CO2 pressures in stripping conditions, relatively low water vapour pressures in stripping conditions, and good swing capacity. The potential energy savings compared with an MEA system are discussed.