Green cement breakthroughs are setting new standards in construction.
Cement is the prime element of concrete, holding everything from the smallest homes to the tallest skyscrapers. It paves our roads and builds our dams, making modern life possible. But here’s a catch: the production of cement is one of the largest industrial sources of CO2 emissions worldwide. As the world grapples with climate change, this foundational material presents a significant challenge.
The cement industry is aware of its impact on the environment. Recognizing the urgency of reducing its environmental footprint, innovators within the sector are working hard to develop sustainable alternatives. In this article, let’s learn more about the impacts of traditional cement on our planet and explore how the next generation of sustainable cement can lead us to a greener tomorrow.
The environmental footprint of traditional cement
Image from Freepik
The manufacturing process of traditional cement is a significant source of carbon emissions. To produce cement clinker—a dark gray nodular material essential for cement production—raw materials like limestone and other minerals are heated in kilns at temperatures exceeding 1,450 °C. Limestone, a core component of cement, is composed of approximately 40% carbon dioxide (CO2)—a potent greenhouse gas. As it heats up, the limestone releases this trapped CO2 into the atmosphere.
But that’s not it. The high temperatures necessary for this process are maintained by burning fossil fuels such as coal and natural gas, which further contribute to CO2 emissions. Annually, the cement industry churns out over four billion metric tons, accounting for approximately 6-7% of global CO2 emissions, making it one of the heaviest industrial polluters.
Besides CO2, traditional cement production releases other harmful pollutants too, including nitrogen oxides (NOx) and sulfur dioxide (SO2), which are linked to smog and acid rain. Cement plants also emit particulate matter that degrades air quality, posing significant health risks to communities living nearby. Hence, there is a pressing need for cleaner alternatives in the cement production industry to mitigate long-term environmental and public health harms.
Enter sustainable cement—new technologies in cement production
In response to these urgent environmental challenges, startups like Sublime Systems, Brimstone and Fortera are pioneering new methods to produce cement with significantly reduced CO2 emissions, aiming to disrupt the US$410 billion global cement industry.
Image from Sublime Systems’s website
Sublime Systems, founded in 2020 by CEO and Co-Founder Dr. Leah Ellis, completely bypasses the traditional high-temperature cement production process. Rather than using fossil fuels, Sublime uses an electrochemical process to split water into an acid and a base. These substances are then used to dissolve carbon-free rocks, minerals and industrial waste to extract calcium. Using the base produced, this calcium is converted into calcium hydroxide, or lime, and mixed with silicate to produce low-carbon Sublime Cement™. Remarkably, all these steps take place at room temperature, which greatly reduces carbon emissions.
Earlier this year, Sublime Systems set up its first commercial low-carbon cement plant in Holyoke, Massachusetts, anticipated to produce tens of thousands of tons of Sublime Cement™ annually. By May, this groundbreaking low-carbon cement hit the market.
Image from Frontera’s website
Meanwhile, Fortera, a San Jose, California-based company, has developed a technology that mineralizes CO2 released by traditional cement plants. Dubbed ReCarb®, the method can transform the released CO2 into a reactive form of calcium carbonate that can be used in making cement, reducing the carbon footprint of the process by 70%. In April, Fortera opened a new facility in Redding, California, capable of producing 15,000 metric tons of cement annually using this eco-friendly technique.
Another California-based startup, Brimstone, is producing decarbonized cement by replacing limestone with basalt—a rock formed from rapidly cooled lava—and other calcium-rich silicate rocks. These materials are rich in calcium oxide, essential for cement but naturally low in carbon. Brimstone’s method also generates a magnesium compound as a byproduct, which captures atmospheric CO2, potentially rendering their cement production carbon-negative.
Opportunities and challenges in the green cement market
The green cement market, with a valuation of US$29.73 billion in 2023 and a projected CAGR of 8.65% through 2031, is capturing investors’ attention. Venture capital investors like Playfair Capital, Norrsken VC and Kompas VC as well as energy companies such as Vantaa Energy are drawn to the potential of developing cement that is up to 95% greener than traditional cement.
This surge in interest is in line with global efforts to combat climate change and meet stringent environmental regulations. It also reflects the construction industry’s growing commitment to sustainability and eco-friendly materials.
But here’s a shocking reality: despite the clear environmental benefits, the adoption of sustainable cement might be far from assured. A McKinsey study reveals that current technologies only allow the cement and concrete industry to achieve 30% of carbon emission reductions needed to keep global temperature increases below 1.5 °C above preindustrial levels. To achieve this ambitious goal, it demands collaboration across the entire cement ecosystem, including regulators, investors and society.
Matthew P. Adams, an associate professor and co-director of the Materials and Structures Laboratory at New Jersey Institute of Technology, highlights a significant hurdle. “Building codes at the local, state and national level are slow to permit the use of new technologies in building materials, despite extensive strength and durability testing,” he remarks. Adams adds that many public agencies and engineering firms are hesitant to adopt new methods without solid proof of their long-term durability and effectiveness in actual conditions.
To promote the widespread use of green cement, Adams suggests that knowledge and technical data about greener concrete need to be shared with government decision-makers and the broader industry.
Albert Manifold, President of the Global Cement and Concrete Association (GCCA), also stresses the importance of cooperation among industry stakeholders. While the industry is committed to slashing emissions and ensuring that cement production is carbon-neutral by 2050, he acknowledges the substantial challenges involved and the necessity for industry alignment on sustainable practices.
“We cannot however succeed alone, and in launching our ambition statement, we are also highlighting the need for our industry to work collaboratively with other stakeholders in support of our ambition for a more sustainable future,” he notes.
Given the construction industry’s traditional resistance to change, the future of sustainable cement hangs in the balance. It will ultimately depend on how effectively stakeholders across the cement production ecosystem can work together to overcome challenges and drive the industry toward a more sustainable future.
Also read:
- Plastic’s New Leaf: Global Efforts for a Sustainable Future
- 6 Cities That Are Building Greener Futures through Sustainable Urban Design
- Mining Companies Adopting Sustainable Practices to Build a Greener Future
Header Image from Freepik
