Thermodynamic Analyses of Solar Thermochemical CO2 Capture Via Calcination/Carbonation Cycle

The effect of solid and gas phase heat recovery on total energy required for an ideal solar-driven carbon dioxide capture cycle based on calcium carbonate/calcium oxide calcination/carbonation is studied. The effect of varying the carbonation and calcination reaction temperatures on total energy requirements is also investigated. The results are compared to values for minimum thermodynamic work of separation and work available from several common hydrocarbon fuels. For a calcination temperature of 1000°C and a carbonation temperature of 400°C, the addition of solid heat recovery decreased the cycle energy requirement by less than 10% for all considered carbon dioxide concentrations in the input gas stream. The addition of gas phase heat recovery reduced the energy requirements by up to 50%, with the largest decrease occurring at low carbon dioxide concentrations.