Cement plays a critical role in almost all infrastructure and construction. As a result, cement making represents a massive global industry that contributes significantly to CO2 pollution. Producing cement accounts for 7 to 8 percent of annual CO2 emissions worldwide. Confronted by this large carbon footprint, the cement industry is turning to carbon-capturing techniques and renewable energy sources to reduce emissions.
One approach to carbon capture involves trapping CO2 within the cement material itself. Researchers have experimented with mineralized CO2 and mixing it into the cement and other aggregates when making concrete.
An alternative method injects CO2 into the wet mix during pouring. As the final product cures, the gas remains trapped inside the solid material. CarbonCure and Solidia already have used these methods at construction sites and in the manufacturing of precast concrete blocks.
Cement represents 80% of the CO2 emissions attributed to concrete usage. Material scientists have reduced cement needs through the use of substitutes, like iron slag and coal ash. Limestone calcined clay offers another binding agent that offers the benefit of lower production expenses.
In the U.K., the Energy Safety Research Institute from Swansea University has installed a green hydrogen power generator at a Heidelberg Cement facility. When using power from renewable sources, the unit splits hydrogen and oxygen atoms from water molecules. The separated hydrogen provides a clean-burning fuel to power cement processing. This reduces reliance on fossil fuels and cuts CO2 emissions. Additionally, hydrogen fuel trucks could replace diesel trucks currently used to transport cement.
Advances in concrete technologies have the potential to preserve the use of a versatile building material while addressing pollution. How effective do you think carbon capture and renewable fuels will be at decarbonizing the cement industry?
CarbonCure’s vision is to make its carbon dioxide removal technology standard for all concrete production across the globe. By realizing the full potential of CarbonCure’s portfolio of technologies, the goal of saving 500 megatonnes of embodied carbon emissions every year could be met—which would be equivalent to taking 100 million cars off the road.
In order to shrink the carbon footprint of buildings, embodied carbon in new buildings must be reduced. Embodied carbon, or the carbon emitted from the manufacturing of building materials and construction, will account for nearly 50% of carbon emissions from new construction over the next 3 decades. In any given building, concrete can contribute a minimum of 50% of the embodied carbon footprint.
Solidia Technologies has developed a technology platform that enables production of next-generation building and construction materials with outstanding physical properties, lower life-cycle costs and low environmental footprint. Solidia’s “Low Temperature Solidification (LTS)” technology accelerates the natural bonding process of CO2 with minerals to form solids, ensuring that it happens in hours rather than years.
In the building materials industry, this enables the production of stronger and more durable products ranging from facades to floor and roof tiles to decorative countertops. Solidia Technologies is also working to develop materials that can replace concrete. Preliminary findings show that the strength and properties of these materials far exceed those of traditional concrete. The sequestration of CO2 in the production process provides the additional benefit of creating a carbon neutral concrete replacement.
ESRI is housed on Swansea University’s new world class Bay Campus. ESRI provides an exceptional environment for delivering cutting edge research across energy and energy safety related disciplines with a focus on the following areas:
Source: Magoda, 2021-02.