Cement is one of the most commonly used man-made materials in the world. It is also one of the largest sources of industrial carbon dioxide. Cement manufacturing generates about 8% of the world’s carbon dioxide emissions.
In a new article in a magazine ACS Energy LetterResearchers report a new type of cement that uses 70% less energy and reduces carbon emissions by as much as 98% compared to traditional cement production methods.
The new process incorporates an electrochemical conversion step before heating the limestone to reduce the extreme heat required later. Researchers are also using recycled cement and concrete to further reduce carbon emissions.
Cement production is an inherently carbon-intensive process. Emissions occur from two routes. First, the process requires heating limestone (calcium carbonate) and silica to temperatures of over 1,450°C, an energy traditionally obtained from burning fossil fuels.
Second, the chemical reaction itself produces carbon dioxide. That’s because the heat drives out carbon dioxide and turns limestone into lime. The lime then reacts with the silica to form calcium silicate clinker, which is used to make cement.
Instead of cooking limestone and silica in a high-temperature oven, Curtis Berlinguette and colleagues designed an electrochemical reactor that converts limestone and silica into a compound called calcium silicate hydrate. This conversion occurs at a temperature of only 60°C. The researchers then convert the hydrate into calcium silicate minerals in a kiln at 650°C, less than half the temperature used in traditional methods.
The new method requires 70% less energy than traditional methods due to its power usage and lower temperatures. Your carbon footprint will also be reduced.
Then the team went a step further. Instead of using new limestone, they tested the process using recycled waste cement. They found that this could also serve as a source of calcium carbonate to produce calcium silicate hydrate in an electrochemical reactor.
The use of recycled cement has significantly reduced emissions, with each tonne of clinker produced emitting only around 20 kg of carbon dioxide, an almost 98% reduction compared to the production of regular Portland cement.
The study points to a reliable path to dramatically reducing carbon emissions and increasing the circularity of one of society’s most ubiquitous materials, the researchers said.
sauce: Shaoxuan Ren, Tengxiao Ji, Sabrina S. Scott et al. Electrochemical synthesis of calcium silicate hydrates for low carbon cement. ACS Energy Letter2026.
Image based on Getty Images on Unsplash+
