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Capture Carbon in Concrete Made With CO2 (Javascript required):
On a vast grassy field in northern Wyoming, a coal-fired power plant will soon do more than generate electricity. The hulking facility will also create construction materials by supplying scientists with carbon dioxide from its exhaust stream.
A team from the University of California, Los Angeles, has developed a system that transforms "waste CO2" into gray blocks of concrete. In March, the researchers will relocate to the Wyoming Integrated Test Center, part of the Dry Fork power plant near the town of Gillette. During a three-month demonstration, the UCLA team plans to siphon half a ton of CO2 per day from the plant's flue gas andproduce 10 tons of concrete daily.
[...] Carbon Upcycling UCLA is one of 10 teams competing in the final round of the NRG COSIA Carbon XPrize. The global competition aims to develop breakthrough technologies for converting carbon emissions into valuable products.
[...] Cement, a key ingredient in concrete, has a particularly big footprint. It's made by heating limestone with other materials, and the resulting chemical reactions can produce significant CO2 emissions. Scorching, energy-intensive kilns add even more. The world produces 4 billion tons of cement every year, and as a result, the industry generates about 8 percent of global CO2 emissions, according to think tank Chatham House.
[...] The UCLA initiative began about six years ago, as researchers contemplated the chemistry of Hadrian's Wall—the nearly 1,900-year-old Roman structure in northern England. Masons built the wall by mixing calcium oxide with water, then letting it absorb CO2 from the atmosphere. The resulting reactions produced calcium carbonate, or limestone. But that cementation process can take years or decades to complete, an unimaginably long wait by today's standards. "We wanted to know, 'How do you make these reactions go faster?'" Sant recalled.
The answer was portlandite, or calcium hydroxide. The compound is combined with aggregates and other ingredients to create the initial building element. That element then goes into a reactor, where it comes in contact with the flue gas coming directly out of a power plant's smokestack. The resulting carbonation reaction forms a solid building component akin to concrete.
[...] After Wyoming, Sant and colleagues will dismantle the system and haul it to Wilsonville, Alabama. Starting in July, they'll repeat the three-month pilot at the National Carbon Capture Center, a research facility sponsored by the U.S. Department of Energy.
See Also: https://samueli.ucla.edu/ucla-carbon-capture-team-preparing-for-industrial-demonstration/.
(Score: 4, Informative) by Booga1 on Sunday February 09 2020, @12:52PM (2 children)
We're way past the beginning of the descent into Idiocracy... but I digress.
Much of academic research has been turned from a search for pure scientific knowledge into a search for money. [sciencemag.org]
Grants, products, and patents are all ways get that money. In this particular case it's a $20 million contest. From the link in the story [xprize.org].
The team lists on their contest page [xprize.org] that they have at least one patent pending already, so that's definitely part of the equation. They also say "CO₂NCRETE™ has a CO₂ footprint that is approximately 50% lower than that of traditional concrete..." so it looks like it's a probably net gain in capturing carbon after all. Perhaps I am being too cynical here and should give them the benefit of the doubt, but it's getting tougher to not be cynical about this sort of stuff the more you see it.
(Score: 2) by c0lo on Sunday February 09 2020, @01:40PM (1 child)
Net gain? Not possible in the absolute sense.
Lower than the current way of producing cement? Maybe that's the case when comparing with hydraulic cement [wikipedia.org] - based on silicates, it will require higher roasting temperature, but it doesn't require CO2 to cure - thus no CO2 absorbtion
But it can't be lower than non-hydraulic concrete - essentially, lime with aggregate.
So, essentially they propose some sort of "concrete bricks" as a solution. But, fired bricks would have the same CO2 footprint [bnpmedia.com]
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by Booga1 on Sunday February 09 2020, @02:40PM
They do say it is for "traditional Portland cement" which is listed under hydraulic cement in the Wikipedia page. Of course, the secret's in the sauce and I doubt anyone but the team and the contest sponsors will know that for a while.
I still suspect you're closer to the truth of the matter than any claim of "50%" improvement in CO2 footprint on their contest page.