Concrete is the backbone of the modern world. As the second most used material in the world, cement lies at the foundation of the spaces we call home, as well as the environments where we work, build, learn, and create. Concrete is the foundation of contemporary infrastructure, yet, it relies on cement, a pollution-intensive component that has historically, and continues, to pose considerable threats to our planet and those who inhabit it. For every ton of Portland cement produced, approximately a ton of CO2 is emitted - contributing up to 7% of global CO2 emissions annually. In 2020 alone, cement production was estimated to be 4.1B metric tons, enough to fill 1.64M Olympic-sized swimming pools.
Every day seems to bring something new to the landscape in our changing climate-impacted world, including new regulations, frameworks for distribution, and technologies. Recently, Lt. Gov. Dan Patrick has asked the Texas Commission on Environmental Quality, the state’s environmental agency, to halt approving permits for cement production plants in Texas until the 2025 legislative session citing air and water quality, local economy, and public health concerns. Lt. Gov. Patrick’s actions indicate a growing trend toward balancing cement production with environmental and public health considerations, suggesting that future cement production in Texas, and around the globe, cannot be severed from sustainability.
In terms of cement production, regulation has its place. In a similar fashion to the energy industry, regulation will be a valuable tool in ensuring that progress is made and the efforts tied to them are as scalable as they are impactful long-term. However, if we pause to investigate the innovation in the cement industry we’re faced with an interesting reality: the private market has proven to be innovative enough to create solutions that make legislation a secondary solution.
Over the past decade, we’ve seen carbon capture techniques emerge as a critical focus in the global effort to combat climate change. With the pressing need to reduce carbon emissions among both environmental concerns and regulatory pressures, as technology continues to advance and costs decrease, carbon capture is increasingly viewed as a crucial tool in the transition to a more sustainable and low-carbon future.
However, in the cement industry, when played out over time, an over-reliance on carbon capture puts incredible pressure on both the infrastructure and the marketplace. Firstly, the sheer scale and complexity of cement plants make retrofitting them with carbon capture equipment a daunting – and often, unfeasible – task. Cement production involves high-temperature kilns and various chemical reactions, which can make capturing CO2 emissions and sequestering them technically challenging and cost-prohibitive to deploy at scale. Furthermore, cement plants are often located in diverse geographical regions with varying regulatory environments and economic conditions, making a standardized approach to carbon capture impossible across the industry.
To exacerbate the cost element, construction costs are consistently on the rise. Paired with the marketplace’s inability to absorb more costs for technology, such as carbon capture and storage, the ideal solution is to avoid the production of CO2 entirely.
According to the International Environmental Agency, despite the cement industry being one of the most cost-intensive applications of the technology, capture and storage have been touted as “currently the only scalable solution for reducing emissions.” To me, this feels more like an admission of defeat in innovation.
On carbon capture, we challenge the premise. The innovation does exist – as laid out in our following paragraphs. Innovative technologies and products in the cement industry have created opportunities to reduce the amount of carbon that enters the environment in the first place, deprioritizing regulation while simultaneously championing cutting-edge solutions that are more cost-effective and viable for transition to true zero construction.
The emergence of low-carbon cement, which may offer a less expensive route to decarbonization when compared to carbon capture and storage, relies on the availability of raw materials.
In order to effectively decarbonize cement and move toward net zero, we must start at the root of the problem – the embodied CO2 associated with carbonate rocks. Carbonate rocks, primarily limestone and dolomite, are abundant in the Earth's crust. Historically, limestone has been an essential raw material in the production of Portland cement, serving as the primary source of calcium. Though revered for its durability, low cost, versatility, and grindability, the use of limestone in cement production has been, and continues to be, a major contributor to greenhouse gas emissions and public health concerns. The direct consequences tied to our changing climate could never outweigh those of limestone use in concrete production.
A true shift in carbon emissions from cement production takes shape in the form of an alternative raw materials source. Silicate rocks, like granite, clay, slate, sand, gravels, and basalts, harbor no or very low amounts of calcium carbonate. Paired with their widespread availability, low cost, and ability to improve the durability and longevity of concrete, the use of silicate rock in cement production offers an avenue toward net zero without sacrificing quality, sustainability, or profitability. Already, companies across the construction industry have recognized the value of implementing less carbon-intensive raw materials, such as rice husks, ground glass, and eggshell lime.
In addition to leveraging abundant raw materials, using existing infrastructures and mines to develop cement alternatives is another necessary step in reaching net zero.
Today, opening new mines and finding plant locations is a huge bottleneck in meeting the seemingly ever-growing cement demand. In my view, opening a new aggregate mine is not a viable solution for sourcing raw materials. To start, the permitting process alone takes an average of 15 to 20 years, a timeframe we cannot afford. Additionally, the permitting process offers no guarantees of the mine successfully opening.
For decades, across North America, many well-positioned cement plants and aggregate mines have been filling the need for basic infrastructure. In the face of cement decarbonization, their offerings do not waiver. Existing aggregate mines and cement plants are a wealth of resources for sustainable raw materials. Looking ahead, we can rely on them to consistently provide the raw materials needed to make moving toward net zero a reality. However, to maximize efficiency and scalability, emerging cement alternatives should be designed to be compatible with industry standards, the machinery, and processes already in place at aggregate mines and cement plants. Doing so ensures seamless integration as minimal modifications would be required to incorporate the new cement into existing operations.
Leveraging existing infrastructure also reduces transportation costs, which have burdened local infrastructure and greatly contributed to carbon-intensive components of cement production. In construction, the transportation of materials of any kind creates a larger carbon footprint and takes a percentage off of your margins.
The solution to cutting transportation costs can be found within what surrounds us – local aggregate mines, cement plants, and raw materials. In this case, sustainable innovation doesn’t require us to start from scratch. We can augment the investments, infrastructure, resources, and assets already in place while minimizing environmental impact, cost, and disruption to local communities.
To reach net zero emissions, we cannot fully rely on regulation. Doing so has the potential to curb the innovation of the private market which is currently making major strides towards our environmental imperative. The cement industry has provided us with an example of the unintended consequences of regulatory overreach, while the private market is commercializing multiple solutions that are better economically, environmentally, and socially. Innovation in the cement industry has set the stage for a promising transition to true zero.
The right next steps involve ensuring we’re clearing the path for this success to continue, including shifting to clean energy sources and emphasizing permitting. By innovating with existing materials and technologies, while embracing ongoing advancements and challenges in decarbonization, we have the potential to fundamentally transform the cement production process to be significantly less carbon-intensive – ultimately ensuring a safer, more sustainable, and healthier future for us all.
Bill Yearsley has over 40 years of experience as a construction material professional and has been a leader in making these industries greener and more sustainable. As CEO of Terra CO2, he brings extensive experience with operations, R&D, mergers and acquisitions, capital raising, and management of public and private companies. During the 1990’s Bill was executive director of Redland PLC, a FTSE 100 firm with 4.28B in revenues. He also led their worldwide aggregates group as chairman and CEO. Bill also co-founded a privately held company that performed heavy civil infrastructure projects throughout the western US with 1600 employees.
