Injecting carbon dioxide into concrete not only captures and stores the harmful pollutant, it also adds extra strength to the industrial material, as companies around the world are finding.
Concrete, the world’s most abundant man-made substance, ranks second to coal as the world’s dirtiest industrial material. Now, a company in Halifax, Canada, is working to make concrete plants carbon neutral, using captured CO2 to improve their product.
By injecting CO2 into concrete during production, CarbonCure sequesters stores that would otherwise pollute the atmosphere. According to Sean Monkman, the company’s Vice President of technology development, CO2 makes concrete stronger and more durable – qualities that translate into reduced waste and energy consumption, and reduced costs for manufacturers and builders.
“CO2 isn’t just a harmful greenhouse gas”, says Robert Niven, CEO of CarbonCure. “We can use it to make better materials.”
Niven isn’t alone in spotting this potential. California-based Celera sends its emissions through seawater to create a chalky bicarbonate by-product that, when mixed with concrete, improves its quality. Celera has built a demonstration plant in Monterey to showcase the “beneficial uses” of CO2. Carbon Sciences, also in California, offsets CO2 emissions from coal and steel production plants by sequestering the greenhouse gas in concrete, thereby strengthening the material. And Novacem of London says that its magnesium silicate cement absorbs enough emissions to make it carbon negative.
To date, however, companies have not demonstrated that clean concrete can be produced to meet industry demands, or that the energy used to build new “green” production plants won’t counter its ecological benefits. According to Noel Morrin, Senior Vice President of sustainability at Skanska, effective carbon storage in concrete is “never going to be more than an interesting lab experiment”.
But Niven’s model may have an answer to these concerns. Rather than building new production plants, CarbonCure is partnering with North American manufacturers, including Basalite and Atlas Block, to bring their concept to facilities that already have established markets and the capacity to produce large quantities. Currently, they’re working with three plants in the US and Canada. Plans to expand include the development of other product types, including pipes and pavements. – Katherine Rowland