Rethinking cement and concrete could pave the way to net zero

As one of the world’s most polluting industries, decarbonizing cement and concrete production is critical if we are to reach 2050 net zero goals and limit global warming to a 1.5°C increase from pre-industrial levels. Suppliers must think boldly in terms of scale and technology; not just to reduce carbon emissions from existing processes, but reimagine how cement is produced.

This includes moving away from traditional carbon-intensive Portland Cement manufacturing methods and materials, and developing solutions reducing the amount of clinker required. Clinker production is by far the most carbon-intensive stage in cement and concrete production, contributing 88% of the sector’s current total CO2 emissions from the burning of fuels to allow kilns to reach the 1,450°C required for clinkerisation and through the natural chemical reaction of limestone calcination.

To connect suppliers of near-zero cement and concrete with demand players, and help surface and scale deeply decarbonizing technologies, the First Movers Coalition (FMC), the world's largest private sector demand signal for emerging climate technologies, launched the First Suppliers Hub in January 2024. It is a growing global repository of suppliers and technologies that aim to meet FMC commitment thresholds across high-emissions sectors by 2030, so far featuring over 80 decarbonization projects and displaying information on projects’ technology, maturity, geography, readiness date and current technology readiness level according to these companies' disclosures. Within the cement & concrete sector, there are currently over 30 projects, with more due to be added shortly.

Some suppliers are reimagining the cement and concrete production process in terms of process, chemistries and raw materials. Some solutions even have the potential to be carbon-negative, which could transform the cement and concrete industry from a polluter to climate solution. The cement and concrete industry could in future be transformed from a polluter to climate solution.

One such entry in the First Suppliers Hub is Brimstone’s pilot scale plant in Nevada, involving technology that creates both Ordinary Portland Cement and supplementary cementitious materials – which reduce the amount of clinker required in cement – from carbon-free silicate rock. The same rock also yields magnesium residues, which bind with CO2 and permanently removes it from the atmosphere. Meanwhile, Sublime’s First Suppliers Hub projects, also in the US, combine alternative cement production processes and materials. Sublime uses an ambient-temperature electrochemical process that can turn abundantly available non-carbonate rocks and industrial feedstocks into hydraulic cement, which hardens when mixed with water. The company employs alternative process technology, which uses an electrolyzer at ambient temperature with renewable energy and non-carbonate feedstock, reducing energy-based and calcination-based emissions.

As well as Brimstone and Sublime, CarbonBuilt, Chement and Fortera are founders of the US-based Decarbonized Cement & Concrete Alliance, innovating to reduce emissions. CarbonBuilt’s First Suppliers Hub submissions decarbonize concrete production through cement replacement and CO2 utilization. Their process replaces traditional cement with a low carbon, calcium-rich alternative binder that chemically reacts with captured CO2, strengthening the concrete and permanently storing the CO2. This process reduces the carbon footprint of concrete blocks by 70% or above and has been deployed commercially in the United States. The blocks meet all existing performance standards and can be used as a like-for-like substitute for traditional blocks. Fortera’s First Suppliers Hub projects produce its novel cement with 70% less CO2 using traditional fuel sources, and even lower emissions when powered with municipal waste and biomass using their ReCarb CO2 mineralization process. Their process also allows for more efficient use of electric kilns due to lower processing temperature requirements, unlocking a path to carbon-neutral cement when combined with green energy. Moreover, Chement’s solution in the First Suppliers Hub uses renewable electricity instead of coal-fired kilns, while utilizing the same raw materials as traditional cement production. This reduces the energy used and enables easier carbon-capture solutions than traditional production methods.

Embedding recycled materials in cement production is something several suppliers are looking to achieve. Norwegian company Saferock has submitted low-CO2 emissions alternative cement chemistry projects to the First Suppliers Hub. Their product reduces concrete-related carbon emissions and the mining industry’s build-up of waste by using mine tailings, aggregate and activators to make sustainable concrete instead of the traditional method of mixing carbon-intensive cement, aggregate and water. Saferock’s concrete reduces carbon emissions by over 80% compared to industry standards. Additionally, Swedish company Cemvision’s Re-ment product is a near-zero carbon cement made from calcium oxide-rich materials from other industries, with embodied carbon already well below the FMC threshold.

Ecocem is a European building materials supplier rethinking cement production. Their First Suppliers Hub projects use their breakthrough ACT technology, which employs the efficient use of clinker and supplementary cementitious materials in cement and concrete, resulting in a 70% reduction in carbon footprint at scalable levels, something that is typically very difficult for low carbon cements to achieve.

Carbon capture, utilisation and storage (CCUS) technology allows the capture of carbon from clinker production, helping reduce CO2 emissions into the atmosphere. It can be stored or used by multiple industries, contributing to the circularity of production processes. A core element of the Global Cement & Concrete Association’s (GCCA) net zero roadmap is the “re-evaluation of CO2 as a usable commodity rather than a waste product”, particularly as it calculates that CCUS will contribute 36% of CO2 reductions by 2050. This is the single biggest contributor to the industry’s emissions reductions due to the relatively nascent development and scaling of alternative processes and materials. Six CCUS projects across North America and Europe are included in the First Suppliers Hub.

Supplementary cementitious materials (SCMs) are an important tool on the industry’s road to net zero, as their application in cement reduces the amount of clinker required. FMC Trucking member, Holcim, employs fossil-based SCMs such as slags, a by-product from steel production, in its ECOPlanet cement project in the First Suppliers Hub. The longer-term project of ECOPlanet 2.0 aims to replace fossil-based SCMs with alternatives such as calcined clay. As fossil-based SCM availability reduces over the next few years due to evolving industrial value chains, alternative SCMs will become more important. GCCA estimates that reducing the clinker-binder ratio from the current global average of 0.63 to 0.52 could increase the volume of SCMs used by 26% in 2050 and deliver a cumulative emissions reduction of up to 18%.

Numerous solutions have a role in decarbonizing the cement and concrete industry, and combinations of solutions can provide it with the best chance of reaching its net zero goals. They comprise both the scaling-up of existing decarbonizing technologies and solutions across different geographies, and innovation leading to the application of new processes, technologies and materials. Ultra-low carbon cement and concrete even has the potential to be carbon-negative due to concrete’s natural trait of recarbonation, which is a form of carbon sink that absorbs CO2 in the atmosphere. If your company aims to reach FMC near-zero thresholds by 2030, entering your projects into the First Suppliers Hub is a useful way to connect with potential buyers of deeply decarbonized products.