Capturing carbon where it is produced

EPFL engineers in Sion, Switzerland have demonstrated the potential for achieving net-zero and net-negative emissions in essential industrial sectors through the integration of carbon capture and mineralization directly into the industrial processes themselves. Focusing on cement production, steel manufacture, and waste incineration, the study, published in the journal Energy and Environmental Science, offers a cost-effective and energy-efficient approach to reducing CO₂ emissions, contributing significantly to reaching global climate targets.

The study introduces a solution to integrate CO₂ capture and mineralization within the production process itself. The mineralization reaction converts CO₂ to CO₃ in the form of carbonates, which are a safe and long-term storage solution for CO₂. As a further ecological benefit, carbonates can be used as a building material, and the mineralization by-products can be integrated into blended cement formulation. This, in turn, prevents the extraction and manufacture of resources and contributes to reduced emissions and a circular economy.

The research from the Laboratory of Industrial Process and Energy Systems Engineering (IPESE) is a clear example of how system integration–the bringing together of previously separate industrial processes into one system–can significantly lower emissions in key sectors. According to Professor François Marechal, head of IPESE, these sectors need CO₂ capturing to reach carbon neutrality. “Net-zero cannot be reached by replacing fossil fuels with renewable energy alone. In this study, we demonstrate the importance of adopting a process integration approach to reduce the cost of CO₂ capture and sequestration,” says Marechal. According to the research, mineralization achieves the ultimate oxidation state for carbon, guarantees safe and long-term sequestration and solves the problem of finding deep geological locations for sequestration.

Sarah Holmes from the Royal Society of Chemistry had this to say about the impact of the research. “This research demonstrates how these industries could integrate carbon capture and storage in a practical and economically-feasible way. Crucially, the study has also demonstrated the potential for net-negative emissions, opening up new possibilities for these industries to reduce their impact on climate change. This is a great start to building a roadmap to a greener, more sustainable future for cement production, waste incineration, and steel manufacture.”

Reusing materials found nearby and on site
PhD student Rafael Castro-Amoedo shows how taking advantage of the large amounts of waste heat, alkaline solid residues, and process emissions could reduce sequestering costs by 50%. These sectors currently represent approximately 12% of all EU emissions. The study shows that CO₂ could be sequestrated at a marginal cost of up to 85 EUR per ton of CO_2.. On the European continent, this solution would bring a reduction of 860 million tons of CO₂ per year, with savings of 107 billion EUR per year when compared to the social costs of inaction.