Concern of ‘climate change’ could also be meddling with value & components for cement subsequent?! ‘Cement’s carbon downside could have a blunt repair, swap limestone for basalt’ – Search to ‘cut CO2 from about 1,343 lb per ton of cement’ – ‘Limestone brings a built-in climate penalty’ as ‘cost testing’ wanted for brand spanking new course of
Cement’s carbon problem may have a blunt fix, swap limestone for basalt, because modeling suggests energy demand could drop by more than 40% and emissions by over 80%, cutting CO2 from about 1,343 lb per ton of cement to roughly 110 lb with certain rock types
Cement’s carbon problem may have a blunt fix, swap limestone for basalt, because modeling suggests energy demand could drop by more than 40% and emissions by over 80%, cutting CO2 from about 1,343 lb per ton of cement to roughly 110 lb with certain rock types
By ECONEWS
Exerpt: Cement’s carbon problem may have a blunt fix, swap limestone for basalt, because modeling suggests energy demand could drop by more than 40% and emissions by over 80%, cutting CO2 from about 1,343 lb per ton of cement to roughly 110 lb with certain rock types
Cement is under our feet, inside our walls, and poured into the roads we drive on every day. Yet it rarely gets the same climate attention as cars, power plants, or the electric bill sitting on the kitchen counter.
A new study suggests that one of construction’s biggest climate problems may have a surprisingly direct fix. Instead of changing what builders use on job sites, researchers say the industry could change the rock used to make Portland cement, the common binder that helps turn sand and gravel into concrete.
The study found that calcium-rich silicate rocks such as basalt and gabbro could cut energy demand by more than 40% and reduce related carbon pollution by more than 80%.
Why cement matters
Portland cement is used in most modern construction, from sidewalks and bridges to schools and apartment blocks. That everyday usefulness is exactly why its climate footprint is so hard to ignore.
The cement industry accounts for about 4.4% of global greenhouse gas emissions, according to the University of California, Santa Barbara. Jeff Prancevic, a geologist at UCSB, led the work with Cody Finke of Brimstone Energy, and he put the problem bluntly when he said cement “barely registers in the public mind.”
That makes the new study unusual. It does not start with a futuristic building material that contractors would need to learn from scratch. It asks a simpler question. What if the same familiar cement could be made from a different source of calcium?
The limestone problem
Today, cement makers usually get calcium from limestone. The process is reliable, well understood, and more than a century old, but limestone brings a built-in climate penalty.
To make a key cement ingredient called quicklime, manufacturers heat limestone to more than 2,700 degrees Fahrenheit. At that temperature, the rock releases carbon dioxide from its own chemistry, producing about 1,000 pounds of carbon dioxide for every U.S. ton of cement before the fuel used for heating is even counted.
That is why cleaning up cement is not as simple as switching to cleaner power. Even if the kiln runs on greener energy, limestone still releases carbon as it is processed. The trouble starts inside the rock itself.
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