Cement production poses significant difficulties for addressing climate change.

In a significant stride towards a greener future, Fortera's demonstration plant in Redding, California, commenced production of low-carbon cement in 2024. The plant's output boasts a 70% reduction in emissions compared to traditional cement, marking a substantial step forward in the fight against climate change.

The cement industry, it seems, is no stranger to carbon emissions. Contrary to popular belief, only around 40% of cement's emissions stem from burning fuel. The remaining 60% originate from the chemical process itself, making it a critical area of focus for reducing emissions.

To tackle this issue, various low-CO2 cement blends are gaining traction. A comparison of key low-CO2 cement blends reveals that ground granulated blast-furnace slag (GGBS) can replace up to 50% of cement, resulting in reduced production costs by 3-21% and CO2 emissions by up to 43%.

One such promising alternative is Brimstone's "carbon-free cement," which has passed ASTM strength tests, demonstrating its potential in the construction industry.

The growing demand for low-carbon concrete in major construction projects is driving innovation in this sector. As more projects specify low-carbon concrete, companies are incentivised to develop and perfect these eco-friendly alternatives.

The US Inflation Reduction Act's tax credits of up to $85 per tonne of stored CO2 have significantly improved the economics of carbon capture projects, making them more attractive to cement manufacturers.

Other alternatives to traditional cement include slag, LC3, fly ash, and limestone, each of which can reduce concrete's emissions by 9-43 percent without compromising concrete quality.

One company leading the charge in LC3 cement development is the Holcim Group. JSW Cement, another key player, is expanding capacity with projects underway in India, targeting commissioning in 2025-26.

The benefits of these low-carbon solutions are already evident. For instance, CarbonCure has saved over 657,000 tonnes of CO2 across 9.4 million truckloads of concrete worldwide. In Atlanta's 725 Ponce office tower, CarbonCure concrete saved over 680 tonnes of CO2.

The world's two largest cement producers, China and India, are also embracing these changes. China produces around 2.1 billion tonnes of cement annually, equivalent to the combined output of every other nation on Earth. Despite this, China has written LC3 into their national building codes, and major manufacturers like Holcim are scaling up production with plants achieving 50% + clinker reduction. India, too, has incorporated LC3 into their building codes, with major manufacturers ramping up production.

Interestingly, nearly any fraction of cement can be replaced while maintaining design strength. Field trials routinely show equal 28-day strength. Holcim's ECOPact products guarantee "100 percent performance" with a minimum of 30 percent lower embodied CO2. In 2023, Holcim reported billions in low-carbon concrete sales.

LC3, in particular, offers a promising solution due to its use of abundantly available worldwide materials, making it realistically scalable. Fly ash from coal power plants can replace 20-30% of cement and reduce CO2 by about 27%.

The cement industry emitted approximately 1.6 billion tonnes of CO2 in 2022, accounting for about 8% of global emissions. With the adoption of these low-carbon solutions, we are one step closer to a greener, more sustainable future.