The demonstration carbon capture and storage (CCS) plant at Heidelberg Materials’ Brevik, Norway, cement plant is now being commissioned following an official opening in June. At full-scale production of 400,000 t/y (or 55 t/h) of liquefied CO₂, it will be the first full-scale facility in a cement plant, according to the developers. The CO₂ harvested in Brevik is taken by ship for final disposal under the North Sea, as part of the Norwegian government’s Northern Lights CCS project. This site is the furthest developed of the project’s three signed CO₂ sources, which include a Hafsund Celsio waste-to-energy plant in Oslo and, in a second phase, Ørsted and Yara facilities elsewhere.

At Brevik, two kiln strings produce about 135t/h of intermediate product ‘clinker’, which makes Portland cement with the addition of a small quantity (5%) of gypsum. Portland cement makes concrete, when combined with water, sand and aggregates. The core of the process involves pre-heating ground limestone and mixing it, with further heat, in a rotary kiln at 1,400°C, with sand, gypsum and slag. The so-called precalcination and calcination stages are the most energy-intensive and carbon-heavy phases of production.

To generate the intense heat required to calcine the cement, the plant itself burns a mixture of coal (about 20%) and alternative fuels, including bone meal, waste oil, waste anode dust, refuse-derived fuel and diesel for start-ups. ‘Whatever we can get, we burn it,’ quips Anders Skærlund Petersen, Senior Project Manager, Heidelberg Materials Decarbonisation and Process Innovation.

‘Kiln flue gas has a high share of CO₂, at 20–22% CO₂, versus a gas or coal-fired power plant, of around 4 or 12–14%. That makes it less expensive to capture CO₂ than in a coal-fired power plant,’ says Petersen. That fraction is so high because it includes both CO₂ from fuel combustion and from within the limestone itself. The plant captures CO₂ in an amine-based post-combustion process.

Originally mooted as an idea in the noughties (2000–2009), the carbon capture plant has finally been built, partly on the site of a rotary kiln from a previous kiln line. It comprises three main process columns – each dedicated to a step in the process developed by Aker Carbon Capture (now SLB Capturi) – as well as related pipework, valves and instrumentation. First, the plant blows the flue exhaust into a vessel that cleans and cools it to 30°C. (Cooling comes from seawater drawn from a pipe submerged 70 metres below the surface of the Brevik fjord, 750 metres from shore.)

Next, the exhaust enters the 50-metre-tall absorber column, where it is showered with amine in a mix with water, during which the active chemical, an amine, binds to the CO₂. That CO₂-rich amine circulates to the desorber column, which uses heat taken from the kilns and elsewhere to raise the temperature of the fluid to 130°C, which causes it to boil, releasing CO₂ (and water vapour) as gas. That gas is then compressed, chilled and dried (to remove water that otherwise forms damaging ice crystals), to end up liquefied at 15 bar and temperatures of –26°C. Pumped 750 metres, the liquid is held in storage tanks before being offloaded by ship every four days.
 

The carbon capture plant captures only half of the process’ carbon emissions, because the cement plant as a whole does not generate enough heat to regenerate more than half of the amine required to capture it. As it is, the carbon capture facility already uses 33 MW of waste heat from the cement plant, which it supplements with an 8 MW electric boiler as needed, and for start-up. Since capturing all of the emitted carbon would require the same amount of heat again, which would have to be generated from another energy source, with ensuing carbon implications, the company decided to cap capture there.

Looking to the future

‘It’s really exciting that Brevik has started up; it’s fantastic for industry,’ says Michael Walsh, Leilac General Manager for Corporate Affairs. ‘What I’d say is that amines are a mature technology for a first-of-a-kind project; that makes sense as a technology choice, particularly given the innovations in the transport and storage networks. But as a mature technology, there is limited scope to reduce that cost significantly, and inherently there is an energy penalty from regenerating the solvent [2.5–3 GJ/tCO₂]. We aim to provide a lower-cost solution and are looking to demonstrate that.’

Leilac is a subsidiary of Calix, an Australian mineral processing company. It has lots of expertise in, to put it crudely, heating up rocks, including limestone, bauxite (aluminium ore), spodumene (lithium ore) or iron ore. Leilac’s partners include Heidelberg, Cemex and Titan in the US.

Its claim to fame has involved setting up, and running, with €12mn of European funding, Leilac-1, a 25,000 t/y capacity pilot project that produced 98% pure CO₂ from ordinary cement production at a Heidelberg Materials site in Lixhe, Belgium. Since then, it had been setting up a second project four times larger. But after the host plant shut down in early 2024, Leilac and Heidelberg Materials switched to another plant (in Ennigerloh, Germany), and is now in the permitting phases, with hopes of construction next year.

The secret to its success is simple: it separates the furnace exhaust from the lime off-gas by putting each in a different section of two nested steel tubes. A furnace connected to the outer tube raises the temperature of the inner tube wall, and that heat radiates inside the inner tube. Limestone powder dropped from the top of the 30-metre-high inner tube heats up as it falls 30 metres to the bottom and is calcined. Exhaust from combustion goes out one side; exhaust from calcination – which is almost pure CO₂ – out another pipe for transport and use or storage. 
 

Adds Walsh: ‘In theory, there is no heat penalty associated with this technique, which is unique for carbon capture.’ In practice, a retrofit of an existing plant wouldn’t be perfect, and so would experience a small energy penalty (he claims from 0.6–1.0 GJ/tCO₂) because of process integration inefficiencies and the need to convey material around the plant.

‘Amines are a mature technology for a first-of-a-kind project; that makes sense as a technology choice, particularly given the innovations in the transport and storage networks. But as a mature technology, there is limited scope to reduce that cost significantly… We can provide a lower-cost solution and are looking to demonstrate that.’ – Michael Walsh, Leilac General Manager for Corporate Affairs

Another benefit of the two-tube design is that it offers the possibility of different types of heating. Leilac-1 was fired by natural gas, via 24 strategically-placed burners. But the tube-in-tube design could also accommodate alternative fuels of interest to the cement industry such as waste-derived fuels, which could be zero-priced or even cost-negative (as burning them helps dispose of waste). Doing so would also be benefitted by a ready supply of lime, which is a good sorbent for the chlorines and sulphurs often emitted in flue gas from waste-to-energy combustion, Walsh explains.

And there’s an even more intriguing potential opportunity further in the future. Work has just completed at Leilac-1 to replace the inner calciner tube to one that can be resistively heated – like an incandescent light bulb – by attaching an electric current (but DC instead of AC).

Although electric heating might be novel for the cement industry, switching over would reduce the carbon footprint of the materials. And that’s not all. Theoretically, the carbon capture plant’s heating could become a gas-electric hybrid, able to near-instantaneously switch from one to the other, or any ratio in between. That could have several benefits. First, it could take advantage of fluctuations in the price of electricity – in particular times of negative pricing, for example – to lower the overall energy cost of processing.

And the benefits cascade into grid services. Because of the enormous size and scale of cement plants, they could take a lot of grid load on short notice, while maintaining continuous production because of their ability to modulate the electric-gas mix. If such a plant were sited close to significant variable generation sources such as wind and solar that happen to be heavily curtailed at the grid request, it could offtake their electricity.

Roundup
Air Liquide and EQIOM have joined forces in the European-funded K6 project to make carbon neutral the cement plant operated by EQIOM at Lumbres, Pas-de-Calais, France. The project aims to capture around 8mn tonnes of CO₂ over the first 10 years of operation. It would involve installing a first-of-a-kind oxyfuel-ready kiln, powered with a high level of alternative fuel. Air Liquide will support this initiative by supplying oxygen to EQIOM’s production process and by leveraging proprietary Cryocap Oxy cryogenic technology to capture and liquefy the CO₂ emissions. In January 2024, EQIOM announced that it had launched phase one, involving constructing a new clinker line, to start production in 2026.

A UK project has won funding to develop a carbon capture pipeline between cement and lime companies in the Peak District to store emissions below the Irish Sea. If built, the Peak Cluster project would prevent over 3mn tonnes of CO₂ entering the atmosphere every year. A £59.6mn equity investment in Peak Cluster announced in July is made up of £28.6mn from the UK government National Wealth Fund and £31mn through a joint venture vehicle between Summit Energy Evolution (part of Sumitomo Corporation) and Progressive Energy Peak, as well as each of the Peak Cluster cement and lime producers (Tarmac, Breedon, Holcim and SigmaRoc).

In April 2025, Holcim, IGNIS P2X and Exolum announced that they had formed a strategic partnership to develop ECO₂FLY, which aims to transform cement production emissions into sustainable aviation fuel (eSAF). The new facility, located at the Holcim factory in Villaluenga de la Sagra (Toledo, Spain), is designed to capture over 700,000 t/y of CO₂ during cement production. Part of this CO₂ will be combined with green hydrogen produced from renewable energy, to be converted into eSAF, reaching an estimated production of 100,000 t/y. The remaining CO₂ will be stored permanently in geological repositories.

• Further reading: ‘On the horizon: Norwegian CCUS vision soon to be made real’. Despite cost overruns, Norway’s Northern Lights carbon capture, use and storage (CCUS) project is heading towards start-up in 2025, with a first-phase capacity of 1.5mn t/y, rising to 5mn t/y in the second phase. That schedule puts the scheme in the running to be among Europe’s first large-scale CCUS projects to start up.
• Cement and steel production are global drivers of economic growth, but they are also responsible for massive volumes of hard-to-abate carbon emissions. Read more about the findings of a recent webinar by Rystad Energy, which examined some of the options for decarbonisation in line with the Paris Agreement 1.5℃ target.