Concrete

The impact is clear: 40 per cent lower CO2 missions from cement

Published

4 years ago

September 19, 2022

admin

The maths is simple: replace 30 per cent of clinker with calcined clay for up to a 40 per cent reduction in CO2 emissions. It’s smart, it’s efficient, and it’s something almost every cement manufacturer could do right now. Steven Miller, Global Process Line Manager at FLSmidth, shares insights on the naturally occurring mineral that is set to accelerate the green transition of cement.

With 7 per cent to 8 per cent of all global carbon emissions coming from cement production, the pressure is rising. Environmental regulations grow progressively more demanding. Financiers shy away from emissions-intensive investments. And around the world, citizens, governments, and a broad range of other organisations are calling for action on climate change. For the cement industry, it’s the perfect storm – and it calls for innovation and ingenuity. Right now, there is no substitution at scale for concrete. But we all know we can’t continue our current practices. To meet our sustainability commitments in line with the Paris Agreement, we need to make some radical shifts. This challenge presents a new opportunity for a centuries-old material combined with 21ˢᵗ century technology.

Step one: Cut the clinker factor
The science of the cement manufacturing process is well known. Reducing energy consumption and switching from fossil fuels to carbon neutral alternative fuels have the capability to cut CO2 emissions by up to ~35 per cent. But the majority of the CO2 coming from the manufacturing process occurs during limestone calcination. In the future, we hope these emissions will be captured before entering the atmosphere, but right now that technology is still some way off widescale availability. Instead, we have a more accessible solution: Cut the clinker factor – i.e. the quantity of clinker used in the cement mix.

For many years, cement manufacturers around the world have been doing just that. Fly ash from coal fired power plants, blast furnace slag from iron and steel manufacturing, and a range of other natural and manmade pozzolans have helped cement manufacturers achieve clinker factors as low as 0.4 for some cement types.

However, these low clinker factors are not possible across the board. They are highly dependent on local availability. And as coal-fired power is phased out and iron and steel producers work to reduce their environmental impact, the availability of these industry by-products will fall away altogether. What we don’t want is to see the clinker factor increasing again, along with emissions.

Fortunately, we have an alternative. A widely available, naturally-occurring mineral can be activated into a supplementary cementitious material that can replace 30 per cent of clinker and eliminate up to 40 per cent of CO2 emissions.

In some cases, an even higher percentage of clinker replacement is possible. Best of all, the technology to incorporate it into your process already exists. It has a low ROI, and it’s actually cheaper to manufacture than clinker. What are we talking about?

Calcined Clay – the future of green cement
Clay is found almost everywhere in the world, making it a natural solution in regions where a lack of limestone availability drives up the cost of cement. With the right treatment, it makes an excellent replacement for clinker. You may even be able to use some of the equipment you already have on site, further reducing your investment.

The process is simple. We use the best available technologies from the cement and mining industries to optimise clinker substitution while maintaining cement quality.

This begins with our established ET dryer crusher, which is especially designed for materials like clay with up to 40 per cent moisture content. Using waste gases from the preheater, feed material is dried and crushed in one operation, achieving both the required fineness and a free moisture content of just 1 per cent by the time the clay enters the preheater.

From the dryer crusher, the material is fed to the 2-stage preheater/calciner system for calcination. It’s important to note that any fuels you fire in your existing calciner can be used in the clay calciner, including up to 100 per cent waste fuels.

What colour should green cement be?
Perhaps in the future, the natural red colour of calcined clay will be a sign of a green cement. For now, however, our clay calciner includes colour control technology to ensure the final result is traditional cement grey. This will ensure easy adoption by the cement industry’s customers who have had many decades of building grey buildings, bridges and roads – and may need additional time to change their perspective on colour.

The calciner is engineered for consistent clay activation. This ensures you get the uniform product quality that enables you to substitute more clinker in your cement product. After the activated clay has been collected in the bottom stage of the calciner, it is sent to a reducing zone where the colour control process takes place. From there the clay is introduced to a series of cooling cyclones to attain a final product temperature in the range of 100 – 120˚C. Cooling is achieved using fresh air, which is then heated by the cooling clay and recovered for use as combustion air in the calciner. This is significantly more efficient than water cooling and ensures the lowest possible fuel consumption.

Elimi nate f ossil f uels by electrif ying clay calcination To further decarbonise the cement industry, FLSmidth and a series of leading industry experts have formed a new partnership called ECoClayTM.

To reduce CO2 emissions from cement production by up to 50 per cent, the ECoClay partners will develop and commercialise the technology needed to replace fossil fuels in the calcination of clay by fully electrifying the process.

Led by FLSmidth, the global ECoClay partners include US-based industrial heating expert Rondo Energy, cement producers VICAT from France and Colombian Cementos Argos, and the Technical University of Denmark.

Based on the shared research and tests on hightemperature electric heat generation, storage solutions and renewable grid integration, the ECoClay partnership will build a pilot plant at FLSmidth’s R&D Center in Denmark. The consortium will seek to demonstrate how the ECoClay process is superior to the conventional combustion processes, has a smaller physical footprint on site and significantly lower emissions of air pollutants.

According to the project plan, the ECoClay partners expect to be able to commence construction of the first full-scale electric clay calcination installation by the end of 2025.

Up Next

How Energy-Efficient Are We?

Don't Miss

Indonesian exports fall in June

Concrete

Cement Makers Reaffirm Commitment to Sustainable Growth

Published

1 week ago

June 5, 2026

admin

World Environment Day spotlight on innovation and circularity

On World Environment Day, the Indian cement industry reiterated its commitment to supporting India’s climate ambitions through sustainable manufacturing, resource efficiency and the adoption of cleaner technologies.

The Cement Manufacturers’ Association (CMA) said the sector remains aligned with the Government of India’s Net Zero commitments and is accelerating efforts to reduce its environmental footprint while supporting the country’s infrastructure and development agenda.

Parth Jindal, President, CMA and Managing Director, JSW Cement, said the industry is increasingly adopting cleaner technologies, improving energy efficiency and expanding the use of alternative fuels and raw materials. He also highlighted the growing importance of circular economy practices, where industrial by-products and waste streams from one sector are utilised as resources in another.

“The Indian Cement Industry is aligned to the Government’s commitments on carbon mitigation and is accelerating the adoption of cleaner technologies, resource efficiency and circular economy practices while actively exploring the potential of Carbon Capture, Utilisation and Storage (CCUS) as a critical pathway for deep decarbonisation,” said Jindal.

He added that coprocessing industrial waste and by-products helps conserve natural resources, reduce disposal requirements and lower the environmental footprint across multiple sectors.

According to Jindal, sustainability is no longer limited to manufacturing processes but is increasingly influencing investment decisions, innovation strategies and long-term growth plans within the industry.

Echoing similar views, Dr Raghavpat Singhania, Vice President, CMA and Managing Director, JK Cement, said sustainable development extends beyond emissions reduction and must also focus on responsible resource utilisation and waste minimisation.

“Sustainability in the built environment cannot be measured by emissions alone. It is equally about how efficiently we use resources, how effectively we minimise waste and how responsibly we create the infrastructure that will serve future generations,” said Singhania.

He noted that the cement industry is advancing its sustainability agenda through greater resource efficiency, increased circularity, technological innovation and continuous improvements in manufacturing practices. As a key contributor to India’s infrastructure development, the sector has a critical role to play in balancing economic growth with environmental responsibility.

On the occasion of World Environment Day, industry leaders reaffirmed their commitment to supporting India’s climate goals while delivering the materials required for resilient, durable and sustainable infrastructure.

Concrete

Building a Greener Future Together

Published

1 week ago

June 4, 2026

admin

Environmental sustainability requires immediate action, not just long-term commitments and discussions. Recycling, circular economy practices, and technology-driven waste management can help industries reduce environmental impact while supporting sustainable growth.

Author: Jignesh Kundaria, Director and CEO, Fornnax Technology

World Environment Day serves as an important reminder that environmental sustainability can no longer remain confined to discussions, reports, or long-term commitments. The environmental challenges facing the world today demand immediate, measurable, and collective action. Across industries and communities, waste generation continues to outpace our ability to process it responsibly, placing increasing pressure on ecosystems, natural resources, public health, and the well-being of future generations.

One of the most significant shifts required today is a change in how society perceives waste. Rather than being viewed as a material to be discarded, waste must be recognised as a valuable resource that can contribute to both economic growth and environmental protection when managed through the right technologies and systems. This mindset forms the foundation of the circular economy model that countries across the world are increasingly adopting to reduce landfill dependence, recover valuable materials, and create more sustainable industrial ecosystems.

India has made meaningful progress in strengthening awareness around sustainability, recycling, and environmental responsibility over the past decade. Significant efforts are being made to formalise the recycling sector through improved infrastructure, technology adoption, policy implementation, and broader stakeholder participation. These developments are creating a stronger foundation for responsible waste management and resource recovery across the country.

However, achieving long-term environmental impact requires collaboration from all stakeholders. Industries, policymakers, technology providers, and communities must work together with greater accountability to strengthen recycling ecosystems, encourage responsible waste management practices, and create sustainable outcomes through consistent execution rather than temporary interventions.

As someone closely associated with the recycling industry, I firmly believe that technology will play a decisive role in addressing future environmental challenges. Advanced recycling systems have the potential to recover valuable resources, reduce pollution, minimise landfill burdens, and conserve energy, creating a more sustainable future for generations to come. This belief is deeply reflected in Fornnax’s motto, “Committed to Create a Green Future,” which embodies our commitment to building long-term environmental value through innovation and responsible action.

At the same time, technology alone cannot deliver meaningful change. Real progress requires intent, awareness, participation, and a shared sense of responsibility. Sustainable development can only be achieved when innovation is supported by collective action and a genuine commitment to environmental stewardship.

On this World Environment Day, let us move beyond conversations and take meaningful steps towards creating a cleaner, greener, and more sustainable planet. By embracing innovation, strengthening recycling ecosystems, and acting responsibly today, we can create lasting environmental impact and secure a better future for generations to come.

Concrete

JK Lakshmi Advances LC3 Cement Expansion

Company highlights commercial production and research partnerships

Published

2 weeks ago

June 1, 2026

admin

The meeting reviewed progress in limestone calcined clay cement (LC3) technology and its commercial adoption in India’s cement sector, focusing on low-carbon alternatives to conventional binders. JK Lakshmi Cement noted that limestone calcined clay cement can reduce carbon dioxide emissions by up to 40 per cent compared with conventional cement and said this reduction supports industry decarbonisation. The company highlighted that it was among the first two cement manufacturers in India to move LC3 into commercial production after the Bureau of Indian Standards approved the technology as a cement standard.

Vinita Singhania said the transition of LC3 from research to commercial production reflected collaboration between industry, academia and international institutions. Maya Tissafi acknowledged JK Lakshmi Cement’s role in advancing LC3 adoption in India and its contribution in taking the technology from laboratory trials to commercial implementation. Both representatives underlined the growing relevance of sustainable construction materials as India expands infrastructure and urban development.

The meeting explored continued collaboration with Swiss research institutions such as EPFL, EMPA and ETH Zurich alongside Indian academic partners and development organisations. JK Lakshmi Cement has been associated with the LC3 initiative since 2014 and worked with EPFL, IIT Delhi, IIT Madras, Development Alternatives and Technology and Action for Rural Advancement. The company conducted one of the earliest industrial trials of LC3 and recently announced commercial production of Green Pro LC3 cement from its Jaykaypuram plant in Rajasthan.

India remains the world’s second-largest cement producer and expansion of infrastructure, urbanisation and housing demand continue to support long-term sector growth, increasing interest in low-carbon technologies. The company reported an annual turnover of more than Rupees (Rs) 60 bn and current cement capacity of about 18 million (mn) tonnes (t) per annum, with a target of reaching 30 million (mn) tonnes (t) by 2030. Apart from grey cement, the company also makes ready-mix concrete, gypsum plaster, wall putty, primers, adhesives and fly ash blocks, and both sides concluded on the need for continued collaboration to develop sustainable construction solutions.