News Excerpt:
In a world-first, engineers from Britain's University of Cambridge have shown that cement can be recycled without the same steep cost to the environment as making it from scratch.
More about the News:
- Researchers at Cambridge University claim to have found a solution to produce cement without associated CO2 emissions, which could massively impact tackling climate change.
- The cement industry accounts for nearly 8% of human-caused CO2 emissions, more than any country except China and the United States.
- To produce cement, the basic ingredient in concrete, limestone must be fired in kilns at very high temperatures usually achieved by burning fossil fuels like coal.
- Cement binds concrete together but the whitish powder is highly carbon-intensive to produce, with the sector generating more than triple the emissions of global air travel.
- With the demand for concrete soaring globally and expected to increase further, finding a low-emission solution for cement production is crucial.
Bright hope for zero-emission cement
- Many efforts to produce "green cement" have been too expensive, difficult to deploy at scale, or rely on unproven technologies that don't achieve near-zero emissions.
- The Cambridge researchers looked at the existing steel recycling industry, which uses electric-powered furnaces to produce alloys.
- They developed a method that tweaks the steel recycling process by substituting a key ingredient with old cement sourced from demolished buildings.
- Instead of waste, the end result is recycled cement ready for use in concrete, bypassing the emissions-heavy process of superheating limestone in kilns.
- This method, with a patent-pending, is described as a "low disruption innovation" that requires little change or additional cost for businesses.
- If powered by renewable energy, these furnaces could potentially produce zero-emission concrete.
- The researchers believe this discovery could provoke "an absolutely massive change" by providing low-cost and low-emission cement.
- Producing zero-emission concrete at scale is crucial for achieving carbon neutrality by 2050, as pledged in the Paris Climate Agreement 2015.
