Manuel del Val, Managing Director at Green Mowers (Civil Engineer)

Burgos, December 4, 2024.- Below I reproduce an analysis by Enrique Dans, Professor of Innovation at IE Business School, on cement and decarbonization due to its interest and the information it provides on more sustainable and healthier construction for all citizens:

Concrete is the most widely used material on our planet after water, but the process of making its main component, cement, which requires the extraction of raw materials and very high temperatures to process them, is responsible for 7.5% of all man-made carbon dioxide emissions.

Which is why a discovery that makes it possible to add used concrete to the process of recycling steel, which both purifies the metal and produces reactivated cement, is so potentially important. If, in addition, this is done using renewable energy, as more and more metallurgical companies are beginning to do (and if they don’t they should be heavily taxed), then we are talking about carbon-free cement and a significant reduction in emissions.

Basically, the process involves crushing used concrete, separating it from the sand and gravel that was added during the manufacturing process, then heating it to remove the water, allowing the resulting clinker to be reused. What’s more, electric arc blast furnaces require a flux material, usually lime, to purify the steel: the substance that is added as a flux captures impurities, and then bubbles to the surface to form a protective layer that prevents the new steel from being exposed to the air.

At the end of the entire process, the flux used is discarded as a by-product. In the new method designed by researchers at the University of Cambridge, the lime flux is replaced by recycled cement paste, and is not only capable of purifying the steel, but if the excess slag is cooled quickly in the air, it becomes a new Portland cement that is perfectly reusable. Some media outlets have described the process as “miraculous”.

I’ve always believed that technology is the solution to all our ills, especially those caused by technology itself. Technology, in one way or another, can always be adapted: when humanity desperately needed cheap energy, we exploited fossil fuels, invented the internal combustion engine, and came up with any number of inventions.

Now that our problem is no longer energy, but the greenhouse gas emissions that previous technologies brought with them, we are generating new ways of obtaining energy and other products that allow us to reduce these emissions to get beyond net zero to net negative and remove emissions from the atmosphere that technology has generated over the last 100 years or so.

Right now, the biggest challenge we face is to keep moving in the right direction, to adopting new technologies, and make sure we don’t back to the past.

Instead, let’s use technology to come up with solutions and adopt them reasonably quickly, driven by environmental, as well as cost and market considerations. Through technology, we can find a way to implement something ambitious and existential as surviving the climate emergency.