Tackling Cement Pollution For Sustainable Urban Housing

The surge in housing demand across major global cities is clashing with the imperative to curb greenhouse gas emissions. This predicament is intensified by the fact that the foundational components of construction projects, namely concrete and cement, are notorious contributors to pollution. Around 7% of the world’s carbon emissions stem from cement production, ranking it among the most environmentally damaging industrial sectors, as per insights.

Claude Loréa, who oversees cement, innovation, and environmental, social, and governance (ESG) matters at the Global Cement and Concrete Association, acknowledges the significance of concrete as a fundamental construction material. She points out that an estimated 75% of the infrastructure anticipated for 2050 remains unbuilt. Nevertheless, the issue lies in traditional portland cement, wherein approximately 90% of emissions arise from the creation of clinker – the binding agent that forms a substantial portion of the final product, uniting water, gravel, and sand.

The traditional clinker production process, involving heating limestone and clay in a rotating kiln at temperatures surpassing 2,700 degrees Fahrenheit, has persisted for centuries. Nonetheless, contemporary enterprises are now seeking to revolutionize this method. Remedies include enhancing energy efficiency, adopting cleaner fuels, capturing carbon emissions, and transitioning to alternative raw materials. A route to bolster sustainability within cement production involves a targeted pursuit of efficiency improvements.

Efficiency enhancements are being pursued as a means to promote sustainability in cement production. Carbon Re, a British startup, employs artificial intelligence and machine learning to optimize fuel consumption. Addressing fuel wastage, which is a prevalent issue in the industry, Carbon Re analyzes real fuel usage data to train its algorithm to predict optimal fuel quantities for specific production targets and sources. Even marginal efficiency improvements yield significant emission reductions, holding the potential to curtail substantial carbon output across plants.

Substantial emission reduction can result from minor efficiency enhancements. O’Sullivan elucidates that a mere 2% reduction in fuel usage can translate into saving thousands of tons of carbon emissions per plant. Beyond the immediate benefits, the implementation of AI in heavy industries offers a promising opportunity to curtail a substantial portion of carbon emissions.

Innovation extends to fuel substitution. Cemex, a major global cement producer, collaborates with Synhelion, based in Switzerland, to produce clinker using solar energy instead of coal. This transformative approach employs mirrors to concentrate sunlight onto Synhelion’s solar receiver, heating the kiln to the necessary temperature without resorting to fossil fuels. Gianluca Ambrosetti, co-chief executive and co-founder of Synhelion envisions a future where thermal energy storage can enable continuous solar-powered clinker production, with commercial viability targeted for 2030.

Additionally, the focus is on carbon capture techniques to mitigate emissions from both limestone and combustion during heat production. The International Energy Agency endorses carbon capture, use, and storage as a strategy to reduce emissions in the industry. Nonetheless, widespread adoption has been sluggish, and the IEA emphasizes the necessity to upscale carbon storage efforts significantly. Industry players such as Heidelberg Materials are pioneering carbon capture and storage facilities to effectively manage emissions. Their approach involves chemical solvents that capture CO2 emissions for liquefaction and storage beneath the seabed.

Heidelberg Materials is constructing a carbon capture and storage facility in Norway, poised to operate alongside its Brevik plant. This initiative aims to capture emissions from production, with a capacity to absorb around 400,000 tons annually once fully operational. By employing amine capture, the facility uses chemical solvents to react with and absorb CO2 emissions. A collaborative effort between Shell, Total, and Equinor transports the liquefied CO2 for sub-seabed storage.

A compelling alternative to conventional materials is also emerging. Partanna, a Delaware-based venture, diverges from the use of portland cement by relying on natural chemistries. The company utilizes a combination of brine from desalination plants and slag, a byproduct of steel production, to create an innovative cement variant. This process occurs at ambient temperatures, sidestepping the energy-intensive clinkering process, while also facilitating carbon dioxide absorption during material reactions.

Partanna’s cement possesses strength comparable to traditional Portland cement, with the added advantage of increased durability when exposed to seawater. In collaboration with the Bahamian government, the company is spearheading the construction of 1,000 affordable homes using its novel cement. The venture is also in discussions with a Las Vegas hotelier for the implementation of its innovative material in a forthcoming project.