The battle to reduce carbon emissions is heavily focused on electricity generation, transportation, buildings, and agriculture, which collectively account for more than 75% of the total. However, there are other sources of carbon emissions that cannot be ignored. Among industrial activities, the production of cement is responsible for 7% of industrial energy use and is the second largest industrial emitter of carbon dioxide. Making cement accounts for about 7% of global emissions.
Concrete is the most abundant man-made material on earth. It is used to build homes, schools, hospitals, and infrastructure. And cement is the key ingredient of concrete as it is the glue that makes concrete strong. But the process of making cement requires superheating calcium carbonate – limestone – which releases massive amounts of carbon dioxide into the atmosphere.
A Canadian startup company has invented a new system for making concrete that actually traps carbon dioxide in it permanently and simultaneously reduces the amount of cement needed to produce it.
CarbonCure’s system takes captured CO2 from other activities and injects it into concrete as it is being mixed. Once the concrete hardens, the carbon is trapped forever because it reacts with the concrete and becomes a mineral which actually makes the concrete stronger even with less cement in it.
Companies are starting to use the CarbonCure system. Thomas Concrete has been using it since 2016 and says it has already prevented 10 million pounds of CO2 emissions. It gets its carbon dioxide for the process from a fertilizer plant that emits it. It is a win-win-win situation. A waste product from some factory generates income for it and even after buying that waste CO2, the concrete manufacturer saves money by using less cement. And everybody wins with a cleaner environment.
Photo, posted March 26, 2014, courtesy of Michael Coughlan via Flickr.