Carbon Dioxide Capture Using Dry Sodium-Based Sorbents

Electrobalance and fixed-bed reactors have been used to study the capture of CO2 from simulated flue gas using a regenerable Na2CO3 sorbent. CO2 capture was effective in the temperature range of 60−70 °C, while regeneration occurred in the range of 120−200 °C, depending on the partial pressure of CO2 in the regeneration gas. Equal molar quantities of CO2 and H2O are produced during sorbent regeneration, and pure CO2 suitable for use or sequestration is available after condensation of the H2O. Capture of as much as 90% of the CO2 was possible at appropriate reaction conditions, and little or no reduction in either carbonation rate or sorbent capacity was observed in limited multicycle tests. The concept is potentially applicable to the capture of CO2 from existing fossil fuel-fired power plants, where amine scrubbing is the only CO2 capture process currently available.