Progress in Calcium Looping Post Combustion CO2 Capture: Successful Pilot Scale Demonstration

The development of Calcium-Looping for CO2 capture has made vast progress in recent time. The technology has become a serious option for CO2 capture from fossile fuel fired power plants. Calcium-Looping is a highly efficient process which uses broadly available natural limestone as a CO2 sorbent. The process uses the reversible reaction (CaCO3 ↔ CaO + CO2) between calcium carbonate and calcium oxide in the temperature range of 650 and 900 °C. This publication presents the results of the work done at IFK to demonstrate the Calcium-Looping process in pilot scale at realistic process conditions. The first experimental campaings with the 200 kWth Dual Fluidized Bed (DFB) Facility have shown hydrodynamic stability as well as high flexibility in operation. CO2 capture efficiencies above 90% were achieved consistently over a broad range of process conditions during multiple hours of operation. The presence of water vapor, which is found naturally in flue gas, was found to significantly improve the CO2 capture efficiency. Sorbent attrition measurements fell within a reasonable range, giving confidence that attrition will not be a major restraint for Calcium Looping.