US Patent 9028607 Carbon dioxide sequestration in foamed controlled low strength materials

A process for sequestering carbon dioxide from the exhaust gas emitted from a combustion chamber is disclosed. In the process, a foam including a foaming agent and the exhaust gas is formed, and the foam is added to a mixture including a cementitious material (e.g., cement-kiln dust, lime kiln dust, or slag cement) and water to form a foamed mixture. Thereafter, the foamed mixture is allowed to set, preferably to a controlled low-strength material having a compressive strength of 1200 psi or less. The carbon dioxide in the exhaust gas reacts with hydration products in the controlled low-strength material and in turn sequesters the carbon dioxide.