Decarbonising industry: Spotlight on cement

TL;DR

• Cement is one the world’s largest emitters of carbon dioxide, responsible for 8% of global emissions, with the majority generated from the combination of fossil fuels used to power the precalciners and kilns used in cement plants to create clinker.

• With demand for cement expected to grow exponentially by 2050, there is a massive economic opportunity for those looking to invest in green cement. The Business Research Company estimates that the market alone will grow from $30.15 billion in 2023 to $47.32 billion by 2028.

• Alongside adapting building design to use less concrete and investigating recycling of waste materials, innovators are looking to reduce the carbon emissions of cement through carbon-curing processes, using alternative binding materials, and capturing the carbon released. There are several pioneering companies in this space including CarbonCure Technologies, LC3, and Solidia Technologies, which are all making strides in reducing the amount of energy required in the cement manufacturing process and capturing any carbon that is emitted.

• With energy efficiency regulations, carbon pricing incentives, and Government and public pressure, construction companies are increasingly adopting green cement and there is real potential for the industry to unlock lasting environmental and economic benefits.

The detail

Cement is one the world’s largest emitters of carbon dioxide. In fact, it’s responsible for 8% of global emissions and, if it were a country, would rank third behind China and the US in terms of emissions produced.

Unfortunately, despite its high emissions, cement is in high demand and is the primary component of concrete, the most widely used man-made material. Cement production has rapidly increased over the last century, growing more than thirtyfold since 1950 and almost fourfold since 1990. China is by far the biggest global consumer, using more cement between 2011 and 2013 than the US did in the entire 20th century.

The most common type of cement used in construction and other industries is Portland Cement. The production of Portland Cement requires extensive quarrying and large kilns that need a large amount of energy to power. 40% of the emissions generated by cement come from the combination of fossil fuels used to power the precalciners and kilns used in cement plants to create clinker – one of the key components of cement.

As these figures show, it’s essential for the environment that the use of cement is either rapidly scaled back or a more sustainable alternative is found. It’s estimated that annual cement emissions need to fall by at least 16% by 2030 if the world is to meet the requirements of the Paris Agreement on Climate Change. That’s where low-carbon cement – known as green cement – could make a substantial difference. Experts predict that introducing proven emissions-abatement methods could reduce emissions by approximately one fifth by 2050.

A billion-dollar opportunity

It's not just an environmental argument; economically, reducing the carbon emissions of cement makes sense. Looking at the growth in demand for cement over the past 70 years, it’s fair to say that demand will be even higher by 2050. This will open up opportunities in the low-emissions cement industry and its supply chain, as well as expanding the market for alternative materials. It’s predicted that capital spending in the industry could double by 2035 to reach $70 billion per yearand the Business Research Company estimates that the green cement market alone will grow from $30.15 billion in 2023 to $47.32 billion by 2028. Some projections even believe it will reach $86.2 billion by 2032.

Decarbonisation could benefit from a multi-pronged approach. Operational efficiencies, technological innovation, and business model changes could all play a part as could optimising the design of buildings to use less cement, rethinking structures and shapes, and introducing alternative materials like cross-laminated timber, prefabrication, and 3D printing. Collecting and recycling concrete waste as well as adopting modular construction methods could also make buildings more efficient and reduce the need for cement.

Introducing low-carbon cement

However, green cement arguably presents the biggest opportunity, both environmentally and economically. This eco-friendly alternative to traditional cement is typically produced using renewable energy, low-emission manufacturing processes, and the integration of sustainable materials like heated clay, unburnt limestone, and industrial waste. Alternative production techniques, changes in cement formulation to lower the limestone content, and clinker substitutes can all also contribute to a production process that cuts emissions by up to 70% while still maintaining cement’s strength and durability.

There are several companies aiming to tackle the cement emissions issue by innovating in green cement. These solutions range from carbon-curing processes – adding carbon dioxide to concrete as it cures – to strengthen the material and reduce the amount of cement required, to using alternative binding materials and capturing the carbon released in cement production.

BioMason, for example, a company in North Carolina has found a way to use trillions of bacteria to produce bio-concrete bricks. Its technique involves placing sand in brick moulds and injecting it with microorganisms, which can produce useable bricks without any fossil fuels or calcination needed. Heidelberg Materials in Germany has introduced a new low-carbon concrete that incorporates recycled construction and demolition waste (an approach that also tackles the growing problem of construction waste management) while Eco Material Technologies has found that treating the ash waste from coal-fired power plants can produce a strong, durable, and quick setting cement that avoids virtually all carbon emissions.

Solidia Technologies is seen as something of a pioneer in the production of low carbon cement and concrete. It has built a name for itself by creating a low-limestone cement that gets its strength from carbonation – exposure to carbon dioxide – rather than hydration like traditional cement. It uses the same raw materials and equipment as Portland Cement, making it an easy substitute to switch into existing systems, but offers significantly reduced carbon emissions thanks to its lower production temperatures and reduced limestone calcination.

A closer look at LC3

One company challenging the emissions generated from clinker is Limestone Calcined Clay Cement or LC3. This innovative organisation tackles both sources of emissions generated in this process: the emissions released from the raw materials and those produced by the intense heat needed. It replaces half of the clinker with calcined clay and ground limestone, which don’t release carbon when heated in the same way that limestone does. The clay is also heated to a much lower temperature, which reduces the amount of fuel required and makes it easier to harness renewable energy.

Not only does the LC3 approach reduce emissions by approximately 40% when compared with conventional cement, but it is also less pervious to water and salt making the roads and bridges it creates more durable and longer lasting. That’s not all; as it requires less energy to produce and uses clay, which is widely available, it can cost 25% less. For each tonne of calcined clay produced, 600 kilograms of carbon can be saved and, if LC3 were to be adopted widely by 2030, it could prevent up to 500 million tonnes of carbon emissions.

LC3 is particularly exciting as it could also benefit the Global South and create world-class local industries in the developing world. That’s predominantly because clay that contains kaolinite is the most suitable raw material for LC3 and one that is abundant across Africa.

Capture and reuse

Carbon capture also has an important role to play in making cement less harmful. CarbonCure Technologies is a Canadian cleantech company, which secured an investment of $20 million in 2024 to expand its carbon capture, utilisation, and storage technology for green cement production.

Many building companies are also teaming up with carbon capture companies to help offset emissions. Multinational building materials company Cemex has partnered with Carbon Clean to capture carbon dioxide at less than $30 per tonneand ideally produce net-zero concrete by 2050, while Holcim, a global leader in building materials, is collaborating with Svante to implement carbon capture technology at its cement facilities in Europe and North America. Svante uses solid absorbents as well as creating filters and machines to actively remove carbon emissions from industrial processes and the air.

Some companies are blurring the lines between carbon capture and cement production by doing both. Fortera, for example, has found a way to turn the carbon emissions captured during conventional cement production into a type of green cement, which is a form of calcium carbonate, and could reduce emissions by up to 70%.

A climate shift for climate change?

The good news is that the green cement industry is experiencing a period of growth. Thanks to tightened building regulations and Government support, building materials manufacturers are under pressure to build low-emissions cement production capacity and add carbon capture equipment to their existing plants. Governments and regulatory bodies around the world are actively promoting eco-friendly building materials and the current market for green cement is valued at $36.1 billion. Green cement has also been used at high profile events like the Paris Olympic Games, which used Vertua lower-carbon concrete to construct and renovate venues.

Construction companies are facing strengthened energy-efficiency codes and regulations and disclosure requirements for their environmental, social, and governance performance that are helping to speed up the adoption of low-carbon cement. Carbon pricing policies incentivise sustainable construction and lower emissions by providing tax breaks for using technology that reduces emissions and financial promotions such as debt linked to sustainability, green mortgages, and eco-friendly venture capital funds provide additional enticements.

Realising the industry’s potential

Even so, the cement sector is still largely dominated by a small number of major producers who are traditionally reluctant to experiment. It’s also true that eliminating emissions will require capital spending and involve higher operating costs; it’s estimated that low-emissions cement production could be 45% more expensive. Sustained Government support will be needed to ensure low-carbon cement can be commercialised effectively.

With the world using four billion tonnes of cement each year, the environmental impact of this material cannot be underestimated. There is a massive opportunity, especially as sustainability becomes increasingly urgent, and green cement offers a truly viable alternative. It’s also worth considering the fact that the cost of making construction value chains more sustainable would amount to just 0.03% of global GDP per year between 2022 and 2035. In return, emissions could be curbed by 12.8% by 2035.

Making the switch to green cement isn’t only necessary, but it’s achievable. A greener future and continued economic growth are within reach.

— Lew 👋

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