CO2 capture from cement manufacture and reuse in concrete

A technology has been developed that utilizes CO₂ in concrete curing to improve the concrete properties. This process has been commercialized and is in use in over 50 ready mix and concrete product sites across the United States and Canada. At the current time ready mix and concrete product companies are using commercial, food grade CO₂ at a high cost. The long term objective is to extract CO₂ from cement plants and then utilize that same CO₂ in ready mix concrete and concrete products made with the cement that produced the CO₂, thus closing the loop. This concept has been presented as one of many projects in the Carbon XPrize and has been selected as one of 27 projects approved for round 2. This XPrize team has selected cryogenic carbon capture as the best solution for extracting CO₂ from cement plant exhaust streams. The cryogenic capture technology has already been trialed at one US cement plant. Lab testing on a simulated exhaust gas stream has already been completed for XPrize validation. A second cement plant CO₂ extraction trial, using cryogenic capture is scheduled for January, 2018. This paper will discuss the two technologies; CO₂ usage in concrete curing and the cryogenic capture of CO₂ from a cement plant exhaust gas stream. The paper will discuss the basics of the Carbon XPrize submissions and status. The future of both technologies and the consequences for the cement and concrete industries will be explored further in the paper.