Decarbonizing the Cement Industry: A Roadmap

If the cement industry were a country, it would be the third-largest emitter of CO₂ in the world — behind only China and the United States. Producing one tonne of Portland cement releases roughly 600–900 kg of CO₂, split between fuel combustion (40%) and the calcination of limestone (60%). This process chemistry makes cement one of the hardest sectors to decarbonize.

Why Cement Is Hard to Abate

Unlike power generation, where you can switch from coal to solar, cement's CO₂ problem is fundamental to the chemistry. Heating limestone (CaCO₃) to produce clinker releases CO₂ as a chemical byproduct — no matter what fuel you use. This is why carbon capture is not optional for cement decarbonization; it is essential.

The Capture Opportunity

The silver lining is that cement kilns produce a flue gas with high CO₂ concentration (15–30%), which makes capture significantly easier and cheaper than direct air capture. Captisme's ARB™ system is specifically engineered for these conditions — our sorbents are formulated to handle the dust, SOx, and NOx typically present in cement flue gas.

• Retrofit installation without major plant shutdown
• 95%+ CO₂ capture from kiln exhaust
• Heat integration with kiln waste heat reduces energy penalty
• Captured CO₂ can be mineralized using the plant's own calcium-rich waste streams
• Carbon credits and EU ETS revenue offset capture costs

A Phased Approach

We recommend a three-phase approach for cement companies: Phase 1 — install ARB™ capture on one kiln line as a demonstration (12–18 months). Phase 2 — expand capture to all kiln lines and integrate with on-site CO₂ utilization or mineralization (2–3 years). Phase 3 — achieve net-zero cement production and monetize carbon credits in voluntary and compliance markets.

We are currently in Phase 2 with three major cement producers in Europe and the Middle East. The results from Phase 1 exceeded expectations — and the business case for full-plant deployment is clear.