The effect of water vapor on the kinetics of CO2 capture using CaO in the form of calcined limestone was determined by means of a thermogravimetric analyzer. The effect was studied at three different temperatures, 400, 450, and 550 °C; three different partial pressures of CO2, 0.05, 0.15, and 0.5 atm; and four different partial pressures of H2O, 0, 0.02, 0.1, and 0.3 atm. Calcined limestone with a particle size of 100–200 μm was used. For each condition the conversion as a function of time was determined. At 400 and 450 °C, water vapor had an accelerating effect on the conversion of CaO to CaCO3. At 500 °C, water vapor had no accelerating effect, instead it had a slightly retarding effect on carbonation. Regardless of the partial pressure of water vapor, higher temperature resulted in higher conversion. To study possible mass transfer limitations the effect of diluting the CaO sample with inert SiO2 was also studied.
- Water vapor
- Mineral carbonation