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Cement is the Source of About 8% of the World's Carbon Dioxide Emissions (bbc.com)
Concrete is the most widely used man-made material in existence. It is second only to water as the most-consumed resource on the planet. But, while cement -- the key ingredient in concrete -- has shaped much of our built environment, it also has a massive carbon footprint. From a report: Cement is the source of about 8% of the world's carbon dioxide (CO2) emissions, according to think tank Chatham House. If the cement industry were a country, it would be the third largest emitter in the world -- behind China and the US. It contributes more CO2 than aviation fuel (2.5%) and is not far behind the global agriculture business (12%). Cement industry leaders were in Poland for the UN's climate change conference -- COP24 -- to discuss ways of meeting the requirements of the Paris Agreement on climate change. To do this, annual emissions from cement will need to fall by at least 16% by 2030.
If you're looking to cut CO2 emissions, please look elsewhere. Concrete is pretty much essential to life as we currently know it in the civilized world. Let's go back to building with wood and replicate the 1906 fire in San Francisco...
Concrete contributing to CO2 has been known for a while - that is why at this point there are a lot of solutions to that problem, including concrete variants that sequester or even absorb CO2.
Notice how old some of the results in that search are...
If CO2 is really a problem, local governments will seek to adopt some of those ideas.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Not sure how this is suddenly news. It's been called out since the very first IPCC report, and known long before that.
This is part of why nuclear power and hydroelectric power aren't exactly green. Far better than fossil fuels, sure, but much worse than an equivalent solar or wind farms in terms of CO2 release. The amount of concrete used in both nuclear plants and hydroelectric dams is massive. It dwarfs the pads for solar panels and wind turbines.
But like everything, it's complicated. Turns out that over decades, concrete actually absorbs a large amount of CO2. It seems to be close to half that released when making it. If carbon capture could be used during production, over its lifetime, concrete could become carbon negative. And alkali-activated cements seem to be on the horizon, taking industrial CO2 byproducts and making them into concrete-like structures.
Velociraptor = Distiraptor / Timeraptor
Concrete is made with cement and aggregate. Cement is not the same as concrete. The two are not interchangeable.
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
Compared to Portland cement (made from chalk and clay and resembling Portland stone in color), which is one of the leading types in use throughout the world today, Ferrock is actually five times stronger. It can withstand more compression before breaking and is far more flexible, meaning it could potentially resist the earth movements caused by seismic activity or industrial processes. One of the unique properties of Ferrock is that it becomes even stronger in salt water environments, making it ideal for marine-based construction projects. And rather than emitting large amounts of C02 as it dries, Ferrock actually absorbs and binds it! This results in a carbon-negative process that actually helps to trap greenhouse gases.
sorry, missed some things in the previous post
Anonymous comments are as pathetic as the anonymous "sources" that contaminate gutless journalism from the New York Time
If you look at the URL for that story, it's from 2016...
if you try to follow the link to ironkast.com, you just get a big "SITE UNAVAILABLE PAGE" message.
So what happened? I remember reading about that before, it seemed like a great idea with a lot of benefits.
It makes me wonder if there was some downside they didn't report in that article... material science is hard stuff (not even joking there. Well maybe just a little).
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Obviously the solution is to tax cement.
There's another problem. Global concrete production is around 4 Billion tons per year. Every year, we're adding 4 Billion tons to the weight of the earth.
Now, the earth is very heavy -- about 6,000,000,000,000,000,000,000 tons. But still, adding 4 Billion tons every year will eventually cause problems.
Like cement, for example?
Ezekiel 23:20
Portland cement absorbs CO2 while setting... Just not as much as it takes to make the clinker using fossil fuels. With solar kilns it could be close to neutral
https://en.wikipedia.org/wiki/...
It is what the pyramids were made from, pour-able limestone.
Well, there is no end to "cost is no object" solutions to greenhouse gas emissions. The problem is that in the real world, cost *is* an object, and a very important one.
This is why cap and trade is a viable, market oriented solution to greenhouse gas emissions. Normally the 182 kg of CO2 that's emitted when I produce a ton of concrete to sell to you isn't part of our transaction. Under cap-and-trade, CO2 reduction becomes a profit center, because if I can reduce my emissions below some reasonable target (e.g. down to 150 kg), I can sell the surplus to someone who can't meet the target.
The problem is that cap-and-trade is not politically viable, because people invested in technology that can't be upgraded are currently dumping their pollution for free.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
The main problem is that two of those "local governments" are India and China - until we figure out a way to get them in check
Since you can't control what they do, the only way you can "get them in check" is to use improved concrete alternatives locally and show ways in which it is superior, so it would naturally be adopted over traditional means.
China and India have also both signed onto global warming accords so it's obvious they are highly motivated to address the issue, otherwise why would they be signatories.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
I assume that they were talking about wood, which isn't mud. But you can most certainly can reduce the carbon footprint of concrete construction itself. My home uses a pozzolanic mix, with about half of the cement replaced by basalt dust, and most of the steel replaced by basalt fibre rebar.
Pozzolanic concrete is slower to set, but has more long-term durability. Chemically, it harkens partially back to Roman concrete. There are lots of different pozzolans besides basalt dust, including volcanic ash, coal fly ash, activated clays, etc.
That last paragraph contained spoilers, so if you don't want spoilers go back and don't have read it.
Because the cement itself is carbon neutral.
Reactions
CaCO3 ==> CaO + CO2
CaO + H2O ==> Ca(OH)2
Ca(OH)2 + CO2 ==> CaCO3 + H2O
So for each molecule of cement you make, you do produce 1 molecule of carbon dioxide. Then to use the cement, you add a molecule of water. And then over time, the result reacts with carbon dioxide (removing the carbon dioxide that was released when the lime was made) and releases a molecule of water.
The only non-neutral production of CO2 from making cement is that from whatever source of energy you use to heat up the calcium carbonate to produce the lime.
Doing a bit of research, it looks like 60% of the carbon dioxide released is from the chemical reaction and 40% from the heat used to drive the reaction. Since the 60% from the reaction will be reabsorbed by the cement, we can ignore it. So the actual amount of CO2 due to cement production isn't the 8% the article mentions, but something closer to 3.2%.
When it sets. Ca(OH)2 + CO2 -> CaCO(OH)2, back to Calcium Carbonate.
Shouldn't we just have more babies?
“He’s not deformed, he’s just drunk!”
Carbon dioxide is released as lime is burned, to make calcium oxide, the primary component of regular cement. As the cement sets, it reabsorbs a great portion, if not all, of the CO2 originally produced. https://www.cement.org/for-concrete-books-learning/concrete-technology/concrete-design-production/concrete-as-a-carbon-sink
Because the CO2 is produced as a point-source pollution, and absorbed in a distributed manner, cement could become carbon-negative by doing the easy point of sequestering the carbon at its source. This is best done by use of a microbial reactor, that is, the gas bubbled into water containing algae and exposed to sunlight. The algae, or its oil, can then be used as fuel. See Boyrtrococcus braunii on wikipedia.
We need to reduce carbon emissions from the sources with the highest marginal reduction per cost. If only there were some way resources could be allocated to that by some kind of magical, invisible hand....
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
This is why cap and trade is a viable, market oriented solution to greenhouse gas emissions.
Cap and trade is only a viable solution to facilitate rent seeking. If you want a solution to greenhouse gas emissions, then assign an objective negative cost and tax it without exceptions.
We need to reduce carbon emissions from the sources with the highest marginal reduction per cost. If only there were some way resources could be allocated to that by some kind of magical, invisible hand....
Inconceivable!