Proposed Zero-Carbon Cement Solution Called 'Absolute Miracle' (newatlas.com) 79
"Concrete and steel production are major sources of CO2 emissions," writes New Atlas, "but a new solution from Cambridge could recycle both at the same time."
Throwing old concrete into steel-processing furnaces not only purifies iron but produces "reactivated cement" as a byproduct. If done using renewable energy, the process could make for completely carbon-zero cement.
Concrete is the world's most used building material, and making it is a particularly dirty business — concrete production alone is responsible for about 8% of total global CO2 emissions. Unfortunately it's not easy to recycle back into a form that can be used to make new concrete structures... For the new study, Cambridge researchers investigated how waste concrete could be converted back into clinker, the dry component of cement, ready to be used again. "I had a vague idea from previous work that if it were possible to crush old concrete, taking out the sand and stones, heating the cement would remove the water, and then it would form clinker again," said Dr. Cyrille Dunant, first author of the study...
An electric arc furnace needs a "flux" material, usually lime, to purify the steel. This molten rocky substance captures the impurities, then bubbles to the surface and forms a protective layer that prevents the new pure steel from becoming exposed to air. At the end of the process, the used flux is discarded as a waste material. So for the Cambridge method, the lime flux was swapped out for the recycled cement paste. And sure enough, not only was it able to purify the steel just fine, but if the leftover slag is cooled quickly in air, it becomes new Portland cement.
The resulting concrete has similar performance to the original stuff. Importantly, the team says this technique doesn't add major costs to either concrete or steel production, and significantly reduces CO2 emissions compared to the usual methods of making both. If the electric arc furnace was powered by renewable sources, it could essentially make for zero-emission cement.
"The first industrial-scale trials are underway this month," the article adds. "Producing zero emissions cement is an absolute miracle, but we've also got to reduce the amount of cement and concrete we use," said Professor Julian Allwood, who led the research.
And the professor has also recorded a thoughtful video visualizing the process — and explaining the significance of their breakthrough.
Concrete is the world's most used building material, and making it is a particularly dirty business — concrete production alone is responsible for about 8% of total global CO2 emissions. Unfortunately it's not easy to recycle back into a form that can be used to make new concrete structures... For the new study, Cambridge researchers investigated how waste concrete could be converted back into clinker, the dry component of cement, ready to be used again. "I had a vague idea from previous work that if it were possible to crush old concrete, taking out the sand and stones, heating the cement would remove the water, and then it would form clinker again," said Dr. Cyrille Dunant, first author of the study...
An electric arc furnace needs a "flux" material, usually lime, to purify the steel. This molten rocky substance captures the impurities, then bubbles to the surface and forms a protective layer that prevents the new pure steel from becoming exposed to air. At the end of the process, the used flux is discarded as a waste material. So for the Cambridge method, the lime flux was swapped out for the recycled cement paste. And sure enough, not only was it able to purify the steel just fine, but if the leftover slag is cooled quickly in air, it becomes new Portland cement.
The resulting concrete has similar performance to the original stuff. Importantly, the team says this technique doesn't add major costs to either concrete or steel production, and significantly reduces CO2 emissions compared to the usual methods of making both. If the electric arc furnace was powered by renewable sources, it could essentially make for zero-emission cement.
"The first industrial-scale trials are underway this month," the article adds. "Producing zero emissions cement is an absolute miracle, but we've also got to reduce the amount of cement and concrete we use," said Professor Julian Allwood, who led the research.
And the professor has also recorded a thoughtful video visualizing the process — and explaining the significance of their breakthrough.
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I don't know what ads you watch, but I'm not sure I've ever seen one where the main person speaking says, "[tentative claim of innovation qualified by institution, field, and time] - but we're not sure yet, we're scaling up to validate it before we can say that with full confidence."
Ads are not known for qualifiers. I'm of the thought that some people are so desperate to be jaded/cynical that they ignore qualifying context and reject information outright. These people conflate having a critical mind (good)
Re: This reads like an ad (Score:4, Informative)
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Ads are not known for qualifiers. I'm of the thought that some people are so desperate to be jaded/cynical that they ignore qualifying context and reject information outright.
Many ads have qualifiers. They just say them really fast or with smiling people and upbeat music so you don't notice.
You sure proved him wrong.
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Yes, they have the minimum number of qualifiers that they're legally obligated to include, which, as you point out, they bury as much as possible. That's not at all the case in the above video, which has no obligation to include qualifiers but does, clearly, and up front. Extremely un-ad-like.
Re: This reads like an ad (Score:1)
An ad for VCs
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Even if it is, what's not to like about it?
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'Even if it is, what's not to like about it?'
It's a lie.
Make dirty concrete.
Burn dirty concrete with green power.
Magic green concrete.
Just like:
Make dirty steel.
Burn dirty steel with green power.
Magic green steel.
The latter we had for over 50 years now and nobody called it 'net-zero' EVER!
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Blast furnaces are giving way to "direct reduced iron". These can use hydrogen derived from electrolysis of water as the reducing agent. This makes for a low-carbon steel.
In metallurgy, "reduction" means removing oxygen from an ore, as most metals are found bound to oxygen. In a blast furnace, coke (purified coal) burns to carbon monoxide, which takes a second oxygen from the iron oxide ore. The burning also supplies heat to make the reaction go faster, and melt the iron into a puddle. But hydrogen is
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Wait, are you saying that recycling is a bad thing?
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Probably an advert.
For a product not on the market that you can't buy?
I think your post reads like an advert, one for the need for fundamental education.
Re: This reads like an ad (Score:1)
It is an ad for VCs
Renewable != clean (Score:2)
Ethanol is renewable, it's made from corn. Burning wood is also renewable. Neither are clean burning, they release carbon into the atmosphere.
"Clean" energy would be a more fitting term here.
"Zero-carbon" means carbon neutral (Score:4, Informative)
A zero-carbon process is generally considered "clean energy" as it is not increasing atmospheric carbon and contributing to climate change.
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The quote is this:
If done using renewable energy, the process could make for completely carbon-zero cement.
This is not a true statement, because not all renewable energy, is zero-carbon.
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Furthermore, what do people think the sacrificial electrodes are made of in those furnaces? That's right, carbon.
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It's not just carbon but coal. At least that's the case for the sacrificial carbon electrodes used in producing aluminum and silicon.
I believe you are mixing up cement production with something else, there's no sacrificial carbon in cement production. Maybe there's a new process I missed, or some definition of "sacrificial carbon" that I'm missing. The carbon from cement production comes from reducing limestone, CaCO3, into lime, CaCO. Those that know chemistry, or are just observant of the chemical not
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Note that "portland cement", the usual binder in concrete, is made from other ingredients in addition to limestone or other calcium carbonate material. It is also burned in a higher temperature furnace. Pure lime can be used as a binder once wetted, but it is slow to harden and does not lock to the other ingredients (sand and gravel usually) as well. Portland cement develops spiky crystals that do a better job, and it gains strength faster at the start, making it more practical for most projects. "Carbo
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Note that...
Noted. I'm just a bit frustrated that the description of the process of recycling the cement leaves out the very important element of releasing the CO2 that's been locked up in the cement from curing. They claim that water is forced out, which I'm sure happens, but that's not the end of it. There will be some CO2 released. I suspect that was left out since that could raise questions on how carbon neutral the process was, or how this is somehow an improvement over how cement is currently being produced.
I
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The quote is this:
If done using renewable energy, the process could make for completely carbon-zero cement.
This is not a true statement, because not all renewable energy, is zero-carbon.
Right. No doubt what was meant was if using a zero carbon energy source, the entire process can be zero carbon.
From what I understand, cement production produces CO2 in two ways: exhaust from the fuel used to heat the cement furnace and CO2 driven from the limestone to make cement. The process outlined sounds like to addresses the latter. Using a zero-carbon energy source addresses the former. If you want to reduce CO2 emissions, either one sounds great and there's no reason to hold up one waiting for the o
Re: "Zero-carbon" means carbon neutral (Score:2)
Moreover just on renewables you canâ(TM)t get the oven hot enough, fast enough for the process of producing cement. The kiln needs to have sufficient BTU for something like 2500-3000C if Iâ(TM)m not mistaken. If unobtainium exists lots of things can be done better. People tried using electric kiln, I think the last one was subsidized during the Obama years and went out of business.
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The terms have become severed from actual meaning in common use.
"Renewable", this was to counter running out of fossil fuels, which was a fake scare from the 1970s. It has nothing to do with pollution.
"Clean", this is low or no pollution energy.
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Renewable stuff might typically be clean as well, but lawsuit hysteria hampered much of it, not just nuclear, but hydro as well.
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It occurs to me nuclear might be clean, but is technically not renewable. Also, if it goes bad, its pollution is way worse than GW.
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Nuclear is also not clean, it generates toxic waste, just not atmospheric waste.
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You are correct, and this was my exact point. Renewable became a buzzword because it was an easier goal to achieve, than clean energy. It was a marketing euphemism. The marketing was highly successful, as today, people associate "renewable" with "clean."
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The quote is this:
If done using renewable energy, the process could make for completely carbon-zero cement.
This is not a true statement, because not all renewable energy, is zero-carbon.
Actually the cement process itself is zero-carbon. Whether the renewable energy is carbon zero is an implementation detail outside the cement process. Using sequestered carbon is NOT part of the cement process itself, the process could be done with with zero-carbon energy.
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The claim is that the process is zero-carbon when using renewable energy. If that renewable energy is, say, burning ethanol (which is renewable) then it's certainly not zero-carbon. If it's powered by wind turbines, then yes, it's zero-carbon.
Its the operational use, not the device (Score:2)
The claim is that the process is zero-carbon when using renewable energy. If that renewable energy is, say, burning ethanol (which is renewable) then it's certainly not zero-carbon. If it's powered by wind turbines, then yes, it's zero-carbon.
Again, that is something outside the cement process itself. Is a Tesla itself not zero carbon if the electricity used to charge the batteries generated from coal? No. The Tesla, like the cement process, is itself zero carbon. Charging the Tesla batteries, or powering the cement process, is something separate, external. You could say that a batch of cement produced is not zero carbon, or that a particular drive was not zero carbon, due to these externalities. In short there is a distinction between a device
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Again, that is something outside the cement process itself
True. But what does that have to do with the validity of the statement? The statement did not limit itself to "the current process itself." The scope of the claim *includes* all the energy used in the process. Read the claim again, I already quoted it for you.
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Now please excuse me while I start up my gasoline based Honda generator to recharge my Panasonic Eneloop batteries.
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The marketers definitely have you where they want you. There is nothing reasonable about that interpretation.
You *could* choose *renewable* gasoline for your Honda generator. Yes, it's a thing! https://afdc.energy.gov/fuels/... [energy.gov]). That will be carbon neutral, right?
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The marketers definitely have you where they want you.
Nope. I am entirely at the mercy of the engineers who choose the implementation details, the sourcing of the requisite power being one such detail.
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Of course, and being driven by financial considerations as they certainly are, the engineers will (directed by the bean-counters in the corporate headquarters) choose the cheapest option that meets the "renewable" definition, which the marketers have taught everyone to equate with "clean energy."
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Of course, and being driven by financial considerations as they certainly are, the engineers ...
Nope. They are driven by the spec for the project. And given a clean cement process they have the flexibility to connect to clean or dirty energy sources as the project spec allows.
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Nobody, and I mean nobody, specifies the cement-making process. They specify the type and quality of cement. The only exception to this rule is when a person or company is specifically trying to demonstrate their product or make a point of their commitment to the environment at all costs.
For the 99.99% of the rest of all projects, yes, the cement provider will be driven by dollars.
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Nobody, and I mean nobody, specifies the cement-making process.
(1) The process is the context of this article.
(2) What I said is that the energy source may be specified for the process (plant).
(3) I am not talking about the engineers for some job, I am talking about the engineers building the cement plant.
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Our points can both be true at the same time.
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This is a distinction without a difference. It’s the UK where this is happening, and in the UK, renewables comprise wind with some solar and a little bit of hydro; they don’t include ethanol. On top of that, the guy is talking to a wide audience using words the way that regular people use them. And regular people use renewable as a synonym for low-carbon.
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regular people use renewable as a synonym for low-carbon
And this is precisely what corporate marketers want, because it's easier for them to claim "renewable" than to claim "low carbon" and people like you don't understand the difference.
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Don't be a dipshit. I obviously understand the difference between the terms. I also am able to distinguish between a Cambridge academic and a corporate marketer, something that seems to escape you. On top of that, I also know the world of marketing well enough to understand that no-one is going to take a company to task for using one synonym rather than the other in customer-facing literature (which is, after all, what marketing focuses on). And I also know that the phrase low-carbon works perfectly well as
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You *seem* to know what you're talking about, but then you still used this phrase:
And I also know that the phrase low-carbon works perfectly well as a synonym for zero-carbon in marketing collateral
The thing is, "renewable" does *not* mean low-carbon, in any way. "Renewable" fuels can actually be *worse* for the air than fossil fuels.
Maybe I was your NatSci professor. Yeah, "organic" has been stretched to meaninglessness by the marketers, even if you *don't* stick to the original definition of "anything carbon-based." That, and "non-GMO" and "grass-fed" and "free range" and "farm-raised" and "small batch" and "heart-heal
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Time for you to toddle off and learn the difference between prescriptive and descriptive English. Whenever it gets a bit tricky to understand the concepts, you can take a moment by patting yourself on the back for your wily ability to spot the malfeasance of corporate marketers, and what a rare gem this makes you.
I am very much sure you did not give Part IA Chemistry lectures at the University of Cambridge in 1992/3.
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My point has nothing to do with my "wily ability." It has to do with the way marketing has twisted meanings to suit their purposes, which are not really about saving the environment.
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Yes, but it's complicated by the fact that zero-net-carbon does not mean pollution-free. For example, I can make all the clean biodiesel I want. Burning it is net-zero carbon, but burning it in air also creates nitrogen compounds that are quite nasty.
True, but with this being a discussion on cement the context would seem to be CO2 and climate change.
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It seems everything is "zero carbon" if it's based on renewable energy.
At least thats the trend I think I see.
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It seems everything is "zero carbon" if it's based on renewable energy. At least thats the trend I think I see.
That's not what is happening here. The traditional cement manufacturing process generates a lot of carbon, this is independent of the energy source. The claim here is that this alternative process does not generate such carbon.
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Have you heard of smoke? That's the gray clouds of stuff that rises from any wood burning fire. There's nothing clean about it.
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Ethanol is renewable, it's made from corn.
The way most ethanol feedstock corn is grown depletes soil, and becomes hydroponics in a dirt medium with the nitrogen coming from synthetic fertilizers. It's not renewable, it's destructive.
"Clean" energy would be a more fitting term here.
At least crushing old concrete is a process you could perform intermittently, when energy is cheap.
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All farming has been that way for over a hundred years. Hello, Haber process. Many billions live today who wouldn't otherwise if we still relied on manure and bat cave mining.
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All farming has been that way for over a hundred years. Hello, Haber process. Many billions live today who wouldn't otherwise if we still relied on manure and bat cave mining.
Humanure is exactly the right answer to this problem, although today it would be compromised by those pharmaceuticals so stable that the majority of them pass through the body unprocessed. This returns micronutrients necessary for life to fields where they can become part of foods again. We make some rough effort at this with sewage sludge, but that's often toxic to some degree for multiple reasons (processing just doesn't handle everything — the left over pharmaceuticals make an appearance here as we
Just being dumb (Score:2)
But in the context of Megaman legends, this headline sounds absolutely brutal, given humans are called "carbons" on it by the antagonists.
Cement Solution Called "Absolute Miracle"... (Score:4, Informative)
By the material's inventor.
This might very well turn out to be amazing, but let's wait and see how the process goes in the real world... if it goes at all.
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if you look closely, the whole thing is a cut & paste job on a breakthrough battery a few months ago . . .
Doesn't seem significant (Score:2, Interesting)
That's great but you use a relatively small amount of material for a massive batch of steel. One old school's worth of concrete could probably supply an industrial steel mill for decades and it also [at least in TFS] ignores the energy requirement to crush and separate the cement in the first place.
Gives us something to do with all the EV batteries (Score:2)
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>"That's great but you use a relatively small amount of material for a massive batch of steel."
That was exactly my thought when I read the summary. I can't imagine this would be very useful. You would need a lot of time and energy to crush concrete to get just the cement. And then you wouldn't use much of that per unit of steel. Yet we are a hell of a lot more cement than steel. Plus, I assume the resulting recycled clicker contains those very contaminates from the steel. Various metals and chemica
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You would need a lot of time and energy to crush concrete to get just the cement.
Just like all those carbon sequestration techniques that use "accelerated weathering" using e.g crushed basalt or granite. They "work" and the chemical equations balance out. But unless all the energy to crush the material is somehow "free" then it's not really a valid way to remove CO2 from the atmosphere.
And if we somehow did find a source of free energy, then we wouldn't need to fool around with any of these techniques. If the energy were free, we would just crack the carbon right out of the atmosphere a
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It doesn't need to be free, but it does need to be green.
OTOH, there was an article here the other day about some place (Gremany?) that was generating so much green energy that they prices turned negative. So if you overbuild solar or wind and then can run the crushing whenever you're generating too much, then this could work. Perhaps. (But I'm not at all sure of the economics of running a crushing plant only when the wind blows. Mills used to operate that way, but there weren't many alternatives.)
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So if you overbuild solar or wind and then can run the crushing whenever you're generating too much, then this could work. Perhaps. (But I'm not at all sure of the economics of running a crushing plant only when the wind blows. Mills used to operate that way, but there weren't many alternatives.)
I've read about the "overbuild renewables" model a bit recently. For the uninitiated, the idea is to deliberately overbuild intermittent renewables until they are producing so much electricity that even during "low" periods of production, there is "enough" for "normal" everyday use. Yes, that's a lot of air quotes!
This would of course lead to "too much" electricity on sunny, windy days, so the idea is to have lots of loads queued up that can be turned on/off at will to use this extra energy. This might be s
Re: Doesn't seem significant (Score:3)
The claim in the BBCâ(TM)s article on the topic is that it could supply 25% of all cement in the UK, and the UKâ(TM)s steel making sector is tiny. Iâ(TM)m surprised too by it being that much, but it seems rather more is used than weâ(TM)d guess.
Re: Doesn't seem significant (Score:1)
Also not sure how realistic it is to separate sand and and stones fromcured concrete in an efficient manner. If it was possible people would be doing it already just for the sake of sand.
Shut down the Drax power station first (Score:4, Interesting)
If the British really gave a shit about climate change, they would stop claiming that it is somehow "green" to cut down trees in north America, then ship them to the UK, then burn them to make electricity:
https://en.wikipedia.org/wiki/... [wikipedia.org]
https://www.bbc.com/news/scien... [bbc.com]
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Everyone is doing it, it's more important to meet Paris agreement on paper than in practice. Rejecting Paris outright to be able to compete with the wood burning economies is not an option, you'd be an international outcast.
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Or they could, you know, do something effective, like reduce consumption (e.g, efficient new buildings, better insulation for existing ones) and concentrate on zero-emission electricity generation. They are doing a pretty good job with wind, and are making some progress with nuclear.
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Biomass can't scale, hell it isn't really renewable ... but as long as everyone agrees to ignore that, it's by far the cheapest way to meet early commitments to emission reduction.
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I don't think Drax even counts as "biomass," considering said biomass is shipped across the Atlantic. That's like claiming to be "solar powered" but a big diesel truck drops off a solar panel every day, then sits there idling until you're finished using the solar panel.
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Why on earth do you think the researchers at Cambridge (who might not even be British) have any control over what happens at Drax, or enforcement by the government of the subsidised behaviour? And why on earth is Canada issuing logging licenses like that?
Avoiding calcination (Score:5, Interesting)
google says half of c02 eneration for cement does not come from energy consumption but comes from the decalcination which occurs during conversion of limestone to clinker. That makes recycling cement to clinker interesting even if it remains as energy intensive as before.
Apparently recycling concrete to clinker is already happening at a commercial level.
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IIUC, this process would release the CO2 that the cement absorbed while it was hardening. I don't think there would be a large net advantage that way over the existing methods. What you'd really be saving is the CO2 generated while mining the raw materials.
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Some kind of concrete recycling is needed to cope with shortages of river sand.
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Does the hardening pick up much carbon then? I didn't know that.
In any case the whole 'miracle' claim is made up and
you have to get to the actual numbers to see what the gain is. How much concrete can you recycle for a certain amount of produced steel for instance.
Transport has to be via green energy too (Score:2)
Say "I don't understand the mineralogy ... (Score:2)
Answer (from a real person, maybe not from ChatPGTips) :
That isn't how cement works, and it has been known since the 1850s. It isn't a straight hydration reaction, it is an actual generation