https://www.bbc.com/news/articles/cxee01m5yero
"Scientists say they've found a way to recycle cement from demolished concrete
buildings.
Cement is the modern world's most common construction material, but it is also
a huge source of planet-warming gas emissions.
That is because of the chemical reactions when you heat limestone to high
temperatures by burning fossil fuels.
Recycling cement would massively reduce its carbon footprint. Researchers say
that if they switched to electric-powered furnaces, and used renewable energy
like wind and solar rather than fossil fuels, that could mean no greenhouse
gases would be released at all.
And that would be a big deal. Cement forms the foundation of the modern
economy, both literally and metaphorically.
It is what binds the sand and aggregate in concrete together, and concrete is
the most widely used material on the planet after water.
It is also a major driver of climate change. If cement was a country, it would
be the third biggest source of emissions after China and the US, responsible
for 7.5% of human-made CO₂.
The problem is the material’s uniquely polluting chemistry.
It is made by heating limestone to up 1600 Celsius in giant kilns powered by
fossil fuels.
Those emissions are just the start. The heat is used to drive carbon dioxide
from the limestone, leaving a residue of cement.
Add both these sources of pollution together and it is estimated that about a
tonne of carbon dioxide is produced for every tonne of cement.
The team of scientists, from Cambridge University, has found a neat way to
sidestep those emissions."
Via Rhysy and Kenny Chaffin.
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
