Cement Production Could Become Carbon Negative with Clean Energy and Direct Air Capture Integration
A new study by researchers at ETH Zurich, in collaboration with the U.S. company Heirloom Carbon Technologies, suggests that cement production, a major source of CO2 emissions, could become carbon negative. The research indicates that combining cement kilns with Direct Air Capture (DAC) technology, specifically calcium looping, could significantly reduce and even reverse CO2 emissions. The study found that 78% of a cement kiln's carbon emissions could be offset if the kiln operates on electricity rather than fossil fuels. Calcium looping, which involves heating limestone to separate CO2 and quicklime, is similar to cement production processes. The captured CO2 is then compressed and stored underground, not bound within the cement itself. The efficiency of CO2 removal is projected to range between 85% and 96% by 2050, depending on the energy mix used. 
