Carbon dioxide utilization in concrete curing or mixing might not produce a net climate benefit

Carbon capture and utilization for concrete production (CCU concrete) is estimated to sequester 0.1 to 1.4 gigatons of carbon dioxide (CO(2)) by 2050. However, existing estimates do not account for the CO(2) impact from the capture, transport and utilization of CO(2), change in compressive strength in CCU concrete and uncertainty and variability in CCU concrete production processes. By accounting for these factors, we determine the net CO(2) benefit when CCU concrete produced from CO(2) curing and mixing substitutes for conventional concrete. The results demonstrate a higher likelihood of the net CO(2) benefit of CCU concrete being negative i.e. there is a net increase in CO(2) in 56 to 68 of 99 published experimental datasets depending on the CO(2) source. Ensuring an increase in compressive strength from CO(2) curing and mixing and decreasing the electricity used in CO(2) curing are promising strategies to increase the net CO(2) benefit from CCU concrete.