Sustainable Industry. Sustainable Planet.

Cement is vital to society, and is particularly important for developing nations. It is an affordable and reliable product that needs to be accessible to all. Unfortunately, it is also inherently carbon intensive, due to the emissions that are directly released during the processing of limestone. As a result, cement production is a major contributor to global CO₂ emissions. Due to most of its emissions being unavoidable this is a proportion that will only continue to increase as other industries decarbonise, particularly the power sector.

The effects of anthropomorphic climate change are well known and are being felt to a greater degree with each passing year. Given the scale of the systems and timescales involved in driving climate change, the need to address carbon emissions can only be described as critical and urgent. The cement industry is coming under increasing pressure to address its own emissions, through the application of regulatory means such as Europe’s emissions trading scheme, as well as a general shift in public and investor sentiment against major carbon emitters.

This background sets the scene for activities already underway to provide the cement industry with a carbon reduction solution. One of these activities is that of low emissions intensity lime and cement (Leilac), a technology, project, and now company formed to provide the industry with a commercial roadmap to decarbonisation.

Low emissions intensity lime and cement technology

At the core of Leilac is an elegant technology solution: the production process is separated from the combustion process by an alloy wall through which heat is transferred. This isolates the cement meal and therefore the source of CO₂ process gas. The CO₂ released through the calcination process (the conversion of the calcium carbonate to calcium oxide and carbon dioxide in an endothermic process) is largely pure, and is subsequently able to be filtered and compressed with little further processing. Not only beneficial to the cement industry, the same core technology is an attractive value proposition for a range of broader industrial applications and industries, including sustainable mineral and chemical processing, battery material production, wastewater treatment, agriculture, and aquaculture. These other opportunities are being developed by Calix, the parent company from which Leilac was born.

From concept to commercialisation

The development of a decarbonisation technology specific to the cement industry is a significant undertaking and it is for this reason that Leilac’s evolution has involved two proof of concept projects.

The Leilac-1 pilot plant received €12 million in funding from the European Commission as part of its Horizons 2020 grant funding scheme and ran from 2016 to 2021. The project was successful in proving the technology could be applied to the decarbonisation of cement, and that relatively pure CO₂ could be generated as an output.

Leilac-2 is designed to deliver a replicable module and is scheduled for integration with Heidelberg Materials’ operational plant in Hannover, Germany from 2023. This retrofit project expands on the proof of concept, with the ambition to resolve four key remaining challenges:

Scaling-up from pilot to nameplate capacity. Leilac-2 will process approximately 20% of a typical plant’s throughput. This will be sufficient to address all risks related to the technology’s application at full scale.

Use of alternative fuels (AF) such as refuse-derived fuels (RDF, e.g. municipal waste), allowing the technology to be ‘energy agnostic’, and use a wide range of energy sources.

The close integration of the Leilac technology into an operational cement plant.

Demonstrating that the retrofit can be integrated without causing issues or major operational interruptions.

Should Leilac-2 be able to fulfil all of the objectives above, it will deliver a step change in capturing carbon emissions in the cement and lime sectors and it may be able to abate CO₂ emissions at a cost of under €30 per tonne. This cost is the net CO₂ abatement cost to produce clinker, including CO₂ compression, maintenance, and CAPEX repayment, and excluding CO₂ transport and storage.

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Read the article online at: https://www.worldcement.com/special-reports/22052023/sustainable-industry-sustainable-planet/