Considerations beyond CO₂ reduction: Life-cycle environmental trade-offs of CCUS technologies for decarbonizing cement and concrete

Abstract

Carbon capture, utilization, and sequestration (CCUS) technologies are increasingly central to achieving deep decarbonization in the cement and concrete industry, particularly given the sector’s process emissions and rising global demand. Based on nineteen cement and concrete decarbonization reports and roadmaps representing countries or regions in five continents, CCUS is projected to account for approximately 24–60% of total CO₂ abatement by the year 2050 (or 2060), with early deployment anticipated within the years 2025 and 2030. Eight CCUS pathways (oxyfuel combustion, mineralization, direct air capture, direct separation, calcium looping, membranes, adsorption, and absorption) are examined with respect to their technological readiness, capture performance, cost ranges, and integration potential throughout life-cycle stages of cement and concrete. Although CCUS technologies provide global warming potential benefits, none deliver uniform benefits to other environmental impact categories. Therefore, CCUS technologies risk the potential for burden-shifting to environmental impacts such as energy use, eutrophication, acidification, human toxicity, and water use. Such environmental impacts are largely driven by energy intensity, sorbent and solvent degradation cycles, and/or material replacement demands. Direct separation emerges as a comparatively streamlined pathway with relatively few cross-category burdens, whereas calcium looping, absorption, and direct air capture exhibit the largest multi-impact penalties. An integrated life-cycle–informed deployment strategy that combines CCUS technologies with renewable energy, electrification, and optimized material flows has potential to address the urgency of the challenge and in parallel the potential to reduce the risk of offsetting CCUS CO₂ reductions with environmental impact trade-offs, burden shifting and/or pollution displacement.