Environment

Today's CO2 may become tomorrow's concrete

J.R. DeShazo (left) and Gaurav Sant show off a sample of the new building material they have created to replace conventional concrete
Roberto Gudino/UCLA
J.R. DeShazo (left) and Gaurav Sant show off a sample of the new building material they have created to replace conventional concrete
Roberto Gudino/UCLA

As carbon emissions continue to rise and cause the planet to warm up, we need to find ways to reduce them. Capturing carbon at the source of its emission is one of the solutions, but there is still the problem of storing all the carbon sucked out of the atmosphere. If that captured carbon could be put to good use, then perhaps we could have the perfect capturing system in place. This is the line of thinking that researchers at University of California (UCLA) are currently pursuing, and they have some big plans for all that carbon: turning it into concrete.

The conversion of carbon into concrete would be a double whammy since concrete production itself is very planet-unfriendly and accounts for 5 percent of all carbon emissions. But an even larger source of CO2 emissions is flue gas, the combustion exhaust gas from power plants, the scientists' main target.

The carbon would be captured and become the raw material for what they call Co2ncrete, using 3D printers in its fabrication. The researchers describe the multi-stage, complex process, which they are still developing, as upcycling.

They started with the idea that capturing CO2 emitted during the calcination of limestone is a feasible method to produce sustainable concrete. Then they set out to investigate how Ca(OH)2 (calcium hydroxide) carbonation would react when exposed to both liquid and supercritical CO2 (the point where distinct liquid and gas phases do not exist). They tested several parameters, including time, temperature and pressure.

For their experiments, the researchers used carbon dioxide with a purity of more than 99 percet. The carbon was extracted from a pressurized reservoir maintained at 20 MPa (megapascal) using a siphon, which was employed in all of the carbonation experiments.

At this stage the material has been produced at lab scale and 3D printed into tiny cones. "We have proof of concept that we can do this," UCLA's J.R. DeShazo says. "But we need to begin the process of increasing the volume of material and then think about how to pilot it commercially."

The researchers would like to see its technology being used by coal-fired power plants in the US as well plants in China and India, which are also global leaders in emissions. They want to create a closed-loop process that prevents carbon from going into the atmosphere while at the same add a great amount of commercial value to the clean-up operation.

"We can demonstrate a process where we take lime and combine it with carbon dioxide to produce a cement-like material," Gaurav Sant, science collaborator to the project, adds. "The big challenge we foresee with this is we're not just trying to develop a building material. We're trying to develop a process solution, an integrated technology which goes right from CO2 to a finished product."

Once they further develop the technology, the researchers will be faced with the equally massive challenge of convincing industry leaders that the technology is good for the planet as well as their bottom line.

"This technology could change the economic incentives associated with these power plants in their operations and turn the smokestack flue gas into a resource countries can use, to build up their cities, extend their road systems," says DeShazo.

The video below features the researchers talking about the science and economics involved in making Co2ncrete.

Source: UCLA

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13 comments
MBadgero
Don't know what they are thinking here. Over time, normal concrete already absorbs carbon dioxide.
FredZoepfl
How about today's CO2 may become tomorrow's transportation fuel: www.chemicals-technology.com/projects/george-olah-renewable-methanol-plant-iceland. This facility makes methanol (CH3OH) from CO2 and water. Methanol can be made into dimethyl ether (DME), which is an excellent diesel fuel. Methanol can also be made into gasoline (Mobil process).
WandaHarding
sssoooooo, in order to ... suck our enough co2 to "fix" climate change, what are we going to do, cover the world with cement.... more than it already is???? Maybe, if it wasn't SSSSOOOOO covered with cement... we would be just a tad better off.... Why is it that people just do not get it.... it doesn't matter what new "gimmick" ya come up with.... technology won't fix it.... because that takes fossil fuels in the first place... and the amount it, might, suck up is miniscule... unless we cover the world with it... We are WAY TOO FAR BEHIND THE 8 BALL.... to try techno fixes.... THERE REALLY IS NOT FIX ANY MORE... FOLKS.... wake up... we might be able to save just a very little bit of life on the planet.... if we give up industrial civilization.... maybe... think... almost 500 nuclear power plants around the world... and what do they need?>.. STABLE POLITICAL SYSTEMS, STABLE ECONOMIC SYSTEMS... STABLE CLIMATE.... we will not have any of these.... with in a few short years... then, ..... it will get very hot.... it will not even take all 500 or so... to melt down... just a few........ more... than what already has.... melted down...
Rumata
Guys, don't let yourself to be fooled. It's just a stupid April Joke!
You can't find free Ca(OH)2 (calcinated lime) in the nature. You should produce it from CaCO3 (limestone), and the production process (calcination) releases CO2. So, if you use Ca(OH)2 to "capture" CO2, you can only "capture back" the anount of CO2 that was released during the production of Ca(OH)2 from CaCO3.
So this whole "research" is totally useless.
Rocky Stefano
@ WandaHarding , Hey I'll meet you in that post apocalyptic world you're hoping for. Can I drive the rig with Charlize?
Rann Xeroxx
The climate is changing, it has been since there has been a climate. And a faction of a percent of a percent of human added CO2 has almost nothing to do with it.
https://wattsupwiththat.files.wordpress.com/2015/10/clip_image0044.jpg
http://iceagenow.info/wp-content/uploads/2011/06/Easterbrook-Natural_global_warming.jpg
xs400
Don't plants increase CO2 intake when there is more available? This sort of research just transfers funds to a bunch of people who perpetuate the "climate change" myth.
worf2
Today's CO2 may become tomorrow's wood! go and plant trees! haha.
Douglas Bennett Rogers
95% of the Earth's greenhouse effect is due to water vapor. The remaining 5% is almost all split between CO2 and methane. 5% of the water vapor is from human operations, mainly irrigation. About one of the 2.5% CO2 has been added by humans. Fast growing wood, such as bamboo, is the main way available to sequester CO2. Irrigation of trees is counterproductive.
Stephen N Russell
Lisc process alone, mass produce, awesome, concrete from air pollution, wild & wow.