Two new products with the potential to revolutionise global decarbonisation

Two innovative products have the potential to revolutionise global sustainability efforts by reducing the carbon produced by construction.

Despite the construction industry’s shift to replacing extractive and polluting materials with ones that are circular and regenerative, the elephant in the room has always been concrete. The breakthrough by researchers at Cambridge to recycle cement looks to be a game-changer,” writes Brigitte Clements, Chair of the Architects Climate Action Network.

She’s referring to work by the University of Cambridge that has found a way of recycling cement to produce ultra-low-emission concrete while also cutting the carbon footprint of steel-making. “The process uses old cement as a substitute for lime flux when recycling steel. This has three outcomes: a reduction in the need for carbon-intensive lime flux to make new steel; a reduction in wasted cement; and an output material that can be used to make new concrete,” writes Greg Pitcher in The Architects’ Journal.

Pitcher continues: “Tests carried out by project partner the Materials Processing Institute showed that recycled cement could be produced at scale in an electric arc furnace. If this furnace was powered by renewable energy, this could produce zero-emission cement. Although cement accounts for only a small proportion of concrete, it is responsible for almost 90% of concrete emissions since it is made through a process called clinkering, where limestone and other raw materials are crushed and heated to about 1,450°C in large kilns. This process releases large amounts of CO₂ as limestone decarbonates into lime. Researchers say they could produce one billion tonnes of sustainable cement per year by 2050 using their method – roughly a quarter of current production levels.”

Carbon-storing plasterboard

Meanwhile, Bristol-based developer of low-carbon and carbon-negative construction materials Adaptavate has produced the world’s first plasterboard to store carbon permanently. This comes through the incorporation of char – produced by the pyrolysis (the heating of an organic material in the absence of oxygen) of lignocellulosic materials such as wood. This locks the CO₂ sequestered by plants into a stable state and subsequently into the board, preventing it from being released through decay. It could take approximately 1kg of CO₂ out of the atmosphere for every m² of plasterboard produced, meaning that this technology is absorbing and storing more carbon than it produces. It has been quantified by Adaptavate’s independent industry-verified carbon calculation tool to the latest EN 15804+A2 standard.

The company repurposes lignocellulosic wastes, combining them with minerals and a small amount of water to create a flat board material. The process requires no natural gas and can absorb low concentration CO₂ in the curing process. Tom Robinson, Founder and CEO at Adaptavate, says: “Plasterboard is one of the most heavily used construction materials after cement and steel, in an industry that produces around 40% of the world’s carbon emissions. As a former builder, the potential impact of putting carbon-storing building materials in the hands of every builder, architect and developer around the world is massive in our global endeavour to decarbonise construction.” 

For more on the Cambridge research, visit b.link/AJ_Cambridge

Read more about Adaptavate at adaptavate.com

Image credit | Alamy