Swiss group Holcim Holcim announces its intention to deploy carbon capture and geological storage of CO₂ (Carbon Capture and Storage, CCS) to reduce emissions from its cement production. This strategy is part of a context where cement manufacturing, notably through clinker calcination, generates approximately 8% of global CO₂ emissions. For the cement industry, which must meet increasingly strict climate objectives, CCS appears as one of the rare technological options capable of reducing process emissions, those resulting directly from the chemical transformation of limestone into clinker and not from energy combustion.
The CCS principle consists of capturing CO₂ at the kiln outlet, purifying it, then transporting it by pipeline to deep geological formations — typically former gas deposits or saline aquifers — where it is injected and stored permanently. Unlike clinker substitution with materials such as blast furnace slag or fly ash, which allows reducing the clinker factor in CEM II or CEM III type cements, CCS directly addresses process emissions, which are otherwise difficult to avoid.
The technical details of Holcim's project — capture capacity, storage sites, commissioning schedule — remain at this stage poorly documented in public communications. However, the approach aligns with the logic of progressive decarbonization that the group has displayed in recent years, aiming to reduce its specific CO₂ emissions per ton of bound material.
CCS technology nevertheless attracts strong criticism. Opponents denounce an expensive, energy-intensive device liable to prolong dependence on fundamentally carbon-intensive processes. According to them, CCS constitutes a form of technological greenwashing that diverts investments from more radical solutions: transformation towards alternative binders with low clinker content, development of carbon concrete, or increased use of recycled construction materials within the framework of circular economy. Moreover, the long-term safety of geological storage — notably the risk of CO₂ leaks or migration — remains a subject of research and regulatory monitoring.
For planners and engineers, the challenge is twofold: assessing whether products from chains integrating CCS will be able to benefit from validated EPDs displaying reduced emissions, and whether these gains will be recognized in certification systems such as DGNB. Economic viability will largely depend on carbon pricing mechanisms, notably within the framework of the future European CBAM. It remains to be seen whether CCS will become an industrial standard or remain a secondary solution, limited by its costs and social acceptability.
