Are we stuck with cement?
theoutline.com
theoutline.com
Massive compared to what? This article highlights that a single wind turbine uses a lot of concrete. But per the latest IPCC assessment, wind power over its life cycle already has the lowest median CO2 emissions of any electricity source. Sure, look for even cleaner ways to make materials, but this rhetoric is terrible. It lets fossil shills bludgeon you with your own words later: "see, environmentalists say coal burning emits massive amounts of carbon dioxide, but they say the same about switching to wind power, so there's no rush to change things."
Here's a recent review article about curbing CO2 emissions from cement:
Global strategies and potentials to curb CO2 emissions in cement industry
https://s3.amazonaws.com/academia.edu.documents/39977040/1-s...
It provides actual numbers and suggestions. Only half of cement's CO2 emissions per ton come from the chemistry inherent in calcining calcium carbonate to produce calcium oxide and carbon dioxide. The rest comes from the fossil sources of energy used to process materials. Like most industrial processes, it can cut emissions significantly just by switching input energy sources. Also, as someone else mentioned, concrete absorbs atmospheric CO2 as it cures. It's mostly the fossil combustion embedded in its production that drives emissions over its full life cycle.
However, it remains true that half of the life cycle emissions of concrete come from fossil combustion. Replacing fossil combustion with other energy sources can cut concrete's CO2 footprint in half without any major changes in concrete's composition or use.
How much carbon dioxide is emitted during a wind farm's construction?
Massive.
How much carbon dioxide is emitted by fossil-fueled automobiles?
Massive.
How much carbon dioxide is emitted by unused cell phone chargers that are left plugged in?
Massive.
The United States stops driving fossil fueled automobiles and unplugs its idle cell phone chargers. How much does it reduce CO2 emissions? Show your work.
It saves one massive from the cars and one massive from unplugging chargers. One massive plus one massive equals a total reduction of two massives.
Find me a way to reduce co2 that involves wicker, green leaves, and pure water, even tangentially, and you'll find huge support for it even if it can be beaten by donating three dollars to a wind farm. That notion will affect a lot of people who aren't even consciously anti-industrial. It's just kind of the default frame of mind when discussing environmental protection.
Or try talking about fixing global warming instead of preventing it. People who are (rightly) very concerned about impending wholesale death suddenly are not interested at all. It comes as an affront. Our mental image of a global warming solution is already clearly set as some type of industrial shutdown.
I think in the future we should create buildings that heal and store carbon instead of pollute tons of carbon dioxide. Magnesium based cements can have huge impact: https://pubs.acs.org/doi/abs/10.1021/acs.chemrev.5b00463
However,I don't see the cement industry changing anytime soon, so I expect innovation in the industry to come from less impactful angles (like http://c8s.co.uk/ and http://www.blueplanet-ltd.com/ ).
If anyone has other insights I'm really curious.
I’ve spent the past few years working in my free time on the restoration of several old buildings, under the guidance of my wife, who is a conservation mason, much of which has comprised removing cement and gypsum plaster and replacing them with lime mortar, lime plaster, and other lime products as appropriate.
While it’s true that most lime products aren’t as strong as cement, and are permeable to water vapour, their CO2 impact is much, much smaller - and many applications which currently see the use of Portland could as easily use appropriate lime-based products. Breathability is a good thing in most structures - most damp that you see in buildings arises from impermeable materials and condensation.
As to strength, lime-Portland blends exist which can create impermeable and strong concrete with less environmental footprint, and I’ve been experimenting with mixing lime with various different aggregates and plasticising agents - resulting in some interesting materials - ground pumice and slate in varying proportions produce very strong (high tensile and compressive properties) and impermeable materials - I was inspired by Roman concrete.
Here’s a tiny bit of further info on CO2 footprints, from a company I’ve bought several tonnes of NHL from:
Modern concrete will not survive like Roman examples have. With the environmental advantages too I'm surprised it hasn't had a resurgence.
You also need much more limestone because the material is weaker, incurring higher environmental impact that way.
To be more accurate - the government decided not to subsidise the project. It was emphatically the right decision - the economics of it were awful compared to wind, solar.
Makes it look solely a political not economic or environmental decision.
1) what do you mean by single skin and double skin exterior walls?
2) are there any simple/quick and fast mixes to DIY a stronger lime mix?
You can do it with non-pozzolonic stone but using ~2:1 lime:crushed terracotta, but it won't have the magic healing properties of the original.
(Note, going off memory on the ratios; they're probably somewhat off).
Seriously, how does this kind of basic unit bungling happen in every report that involves Watts?
Not to mention the stylistic blunder by which a mathematical average, or a bunch of energy (or hey possibly even a turbine), is said to be "working at full capacity." I guess this is a dangling clause? Not sure if that's the right term for it.
Shave off all the fur and you're left with a pretty good sentence:
The turbine will produce about three megawatts of energy on average, which is enough to power 2,400 U.S. homes. (Assuming that figure is right.)
It's shorter too.
Each wind farm has a substation too, which will use some quantity of concrete for equipment pads. And some wind farms built in remote areas have to have their own transmission infrastructure built -- towers, with their own foundations, and switching substations, with again more equipment foundations. You could say concrete is the foundation of our economy... chortle chortle... groan...
EDIT: added SI units for our rest-of-the-world pals
Recently built a foundation for my deck, what was estimated on the concrete tube for pillars was nowhere near what was actually needed.
The "for one month" makes no sense here, but if you drop it the math checks out.
Megawatts are a unit of power. Think of the size of the engine in a car.
Megawatt-hours are a unit of energy. Think of the size of a fuel tank.
Both units are useful: if you run a 1 MW load (a synonym, mostly, for power) for an hour, you'll use one MWh of energy, and have to fuel or pay equivalently.
But increasing the size of your gas tank won't make your car more powerful, and increasing the engine size won't let you drive further between fuel stops.[1]
That serious information outlets still confuse the terms is a bit sad really.
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Notes:
1. Pedants, I love you, welcome to Costco. But I'm excluding second-order effects, which tend regardless to be in the opposite directions.
We see the same variance regionally within the US as well. Canadians use more energy per capita than folks in the US. Cold and hot states dominate energy consumption per capita.
The US does have larger homes and more wealth and does tend to consume more energy per capita across similar environments -- but regional weather patterns create far, far larger differences in energy consumption than any other factor.
We could just as easily say that Europe shouldn't be used as a benchmark as the weather is too nice, on average.
"1 Home” is already a unit of power. One home per month would be energy over time squared. :D
If you're going to talk about the CO2 emissions of the concrete needed for a wind turbine, the obvious next step would be to net them all out and figure out if building wind turbines is a net reduction in CO2 or not.
The author seemed to go out of their way to imply that as long as we use Portland cement, it would not be a net reduction, but they never actually came out and said that.
Not quite sure what to make of it. It's like reading an article that talks about electric cars and how high electricity can make them more expensive than you think, but then...never actually calculates their operating cost and compares it to a conventional ICE powertrain.
It's an investment.
While I agree we need to include all costs in the accounting and improve the concrete industry as well, we shouldn't let the fact that carbon is emitted by concrete creation stop us from making these investments.
Note that you can rewrite that notion to discourage thinking about replacements for lots of things in the modern economy. Oil is a major input into nearly all other investments, so "spending" dino-juice carbon to enable everything else should usually come out a net gain, right?
This is repeated in the article but it doesn't sound right to me. Concrete is mostly stone and sand, with cement only making up 10-20% of the mixture. So both of those should be consumed more than cement is.
By converting the carbonate to oxide, the calcium in cement is free to bond with silicates (and to a lesser extent other compounds).
That CO2 released during manufacture is now looking for a new home, which could either be a plant, or a weathering deposit of limestone which could use the CO2 in the air to convert its own carbonate to stable bicarbonate.
That someone does not share your goals says nothing of their scientific acumen. There are plenty of intelligent scientists working in the concrete industry. Their priorities may be different, but they are not bad scientists.
Concrete is also a consumer product. Real change has to come from the architects and engineers who create the demand. But finding a true low-carbon alternative, a real alternative, is exceptionally difficult. Properly designed and maintained concrete structures can last centuries.
Some protection also uses electrical power. I seem to recall there's a bridge somewhere that uses solar power to keep its rebar from rusting.
The carbon in a tree can get pulled out of the equation for decades while it grows, and partly slow-released as it rots on the forest floor, and partly adapted into the soil, some of which will eventually become a sequestered fossil fuel deposit.
Alternatively, part of the tree can become food, or lumber, or paper, and whatever those eventually decay into may be, at least in part, things other than methane and CO2, safe in the ground as permanent sequestration.
Trees aren't a panacea, but they're a tool we dare not discount out of hand.
There is an entire sector of the economy dedicated to voluntary carbon offsets, and re-forestation efforts are the primary supply. People and companies use these as a sort of carbon tax to offset the emissions they cause by taking airline flights, hosting events, or just living their daily lives.
Everyone creates 100 units of pollution together, say ten firms producing 10 units each.
Then they say, you can only use 90 next year, 70 the next decade, 50 the decade after.
Everyone needs to reduce pollution a bit, this is hard. Some have a 50 year investment in a factory that they can't remodel to pollute less. They'd need to shut down.
Others are more flexible, they can remodel existing infrastructure, or shut down ones that are near the end of their lifetime. But why would they make investments in something more clean?
Trading means one firm producing 10 units can invest in efficiency. Next year it's allowed to produce 9, but its new tech only produces 5. It can sell the other 4 to four factories which couldn't reduce their emissions from 10 to 9.
Over time the polluting parties have funded the non-polluting parties' clean technology, while over time the total pollution has gone down. Moreover, it'll incentivise the lowest-hanging fruit approach, i.e. reduce emissions where it's cheapest to do so, first.
That's why it's called cap-and-trade, not just trade.
Here are the biggest organizations pushing for this — support them if you can:
– https://citizensclimatelobby.org/ (strictly bipartisan)
– https://www.clcouncil.org/ and their PAC, https://twitter.com/afcdividends (conservative/industry-backed)
– https://allianceformarketsolutions.org/ (conservative)
– https://www.s4cd.org/ (campus-based)
No, you put a racing stripe and a spoiler on a dumptruck, and then talked about its aerodynamic qualities.
Not all industries are happy about ecological actions. That game will have winners and losers.. The Earth as a biosphere will "win", but there's a lot of industries that lose.
Last I checked, the Earth's biosphere isn't paying the politicians. The dirty companies, well, they are.
In other words, selection pressure ---biological, cultural, doesn't matter --- always wins in the end. Mother nature has the last laugh.
That 3 bedroom ranch style house in Bangladesh doesn't help anyone if it's under 2m of sea water.
Looks like it is the production of concrete materials that are generating CO2.
ah thats right...nowhere.
the problem is not the industry. the problem is the people who write this and complain about it have not taken any steps to bring these more sustainable cements to market.
The development of more sustainable cements is a challenging but urgent venture. Demand-oriented knowledge formation and the reliance on existing prescriptive standards impede progress towards more sustainable alternatives to conventional cements. None-the-less the last years saw the emergence of a number of technology based start-ups with ambitions to introduce new low-carbon cements as alternatives to traditional Ordinary Portland Cement (OPC). An overall analysis of the Technological Innovation System for cement technology is conducted. This is extended with an investigation of how three start-ups, Celitement, Novacem and Calera perform within this environment. The implementation of new materials requires new types of collaboration between R&D and market actors, a combination of synthetic with the existing analytic knowledge base and redefinition of standards and norms. Moreover, a close cooperation of incumbent actors along the construction value chain is precondition for success of disruptive innovations.