So after the teams pyrolysis step, this is really just carbon dust they're adding to the concrete.
I'm all for locking carbon away in solid objects, and this seems like a good way. One might imagine a law that says "all new cement products must be at least 20% carbon by weight, or pay a $1000/ton tax for missing carbon".
That incentivises locking up carbon in structures, in a form unlikely to escape anytime soon, and gives a proportional fee for anyone who doesn't wish to do so (for example, concrete for very specialist purposes).
Could such a fee create perverse incentives, like in the anecdotal India cobra effect [0].
E.g., to avoid the $1000/ton missing-carbon tax, use a manufacturing technique that only adds $500/ton to the cost of concrete, but also generates far more atmospheric CO2 in the process.
I mean, in a sane world this would be accompanied by a tax on emitting atmospheric CO2 as well. Though I suppose it would make more sense to just allow the amount of sequestered carbon as a write-off against the CO2 tax; no need to set a specific target like "20%".
Because the intent of such a hypothetical law would be to reduce/capture C02, but the end result of it is that it financially incentivizes generating more C02 through some unexpended/unanticipated means.
An unintended consequence might be that yes companies do correctly follow the law and adding carbon to concrete is successful, but also adding carbon to concrete in high enough volumes makes the lifetime of the concrete lesser when exposed to rainwater for long enough, or something like that, resulting in the need to replace the concrete more frequently.
Its the difference between people acting in good faith vs neutral/bad faith with respect to the intent of the law/regulation/etc..
Nitpick: The O in CO2 stands for Oxygen, and is the letter O. It looks like you've used the numeral zero, which looks similar but is not interchangeable.
That's why your regulation should just directly tax what you don't like (like CO2 emissions), instead of going via some weird proxy that's prone to being gamed.
The potential to game things exists everywhere. Tax CO2 and people will want to find ways to technically reduce CO2.
For example, what if it becomes cheap enough to just convert all the CO2 to CO and we dump masses of carbon monoxide into the atmosphere instead? Or if its cheaper to convert CO2 to CO3 which imminently degrades back to CO2 in the atmosphere - would we be confident that the tax law would correctly handle this scenario where the emissions are technically a different substance? Etc..
The U.S. Sulphur Dioxide Cap and Trade Programme seems to be working pretty well. Our CO2 taxation programme only has to be as good as that one.
Yes, loopholes need patching up. The law doesn't need to be perfect, just good enough that complying with the law is simpler and cheaper than looking for loopholes.
Well, you gotta compare the cost-per-kilo of setting up a coffee grounds collection program that gathers X% of the 30+ billion ton/yr of concrete that is used each year.
If the regulations are not properly written, they could be an incentive to start cutting down trees to turn to charcoal as a carbon filler. Companies are sometimes heartless like that.
It would still probably be a better carbon capture plan than capturing it for temporary use in the fuel supply as ethanol. But worse of a measure than just burying the trees
A perverse incentive (like what our ancestor is correctly noting) involves incentivizing something that is antithetical to the goal (not just a side effect). In this case, a policy whose goal is "reduce carbon in the atmosphere" leads to an outcome of "increase carbon in the atmosphere". An unintended effect could just be "makes all the buildings weaker" or "bridges smell like coffee".
It's usually better to have a high fee for things you don't want people to do rather than outright banning something.
For example, rather than saying "planes must not be louder than 80db to land at this airport at night", you could instead say "planes must pay a $$$$ fee to the city for each db over 80db to land at the airport at night". The large fee means loud planes will very rarely land, but when they do it was because it was really worth it to them. The large fee compensates local residents in the form of reduced city taxes over time. If it starts happening too often and the residents don't think they're getting a good deal, they can increase the fee.
I agree, but ideally, the high fee should be proportionate.
Cement is about $130/metric ton. A 30% surcharge seems comfortable. A 100%, I won't squirm at. An 800% surcharge feels punitive, rather than good policy.
I'd like far more surcharges for consumer-unfriendly and environmentally-unfriendly actions, but mostly in the 1-5% range. That's enough to impact most margin-constrained firms, but not so much as to avoid innovation or distort strategy.
Examples:
- Make products repairable
- Provide service manuals and full schematics
- Provide parts at no more than e.g. 2x cost of the product (e.g. if I wanted to buy all the parts for my washing machine to build a new one, it might cost $1000 instead of $500)
- Provide long support lives for e.g. security updates and parts
- Make firmware / software open-source (consider my air conditioner, rather than Microsoft Office)
- Use standard batteries and chargers
- Avoid plastic
- Minimize packaging
... etc.
In a commodity market (like basic air conditioners), a 5% surcharge is way more than enough to influence behavior. On the other hand, if I have a genuinely better battery, or something super-confidential in my firmware, I can still keep it secret at modest cost.
>It's usually better to have a high fee for things you don't want people to do rather than outright banning something.
Why? Any rule with a fine is a rule that the wealthy can just ignore. Why is that a desired attribute of the system?
Your example is great because it doesn't mean that planes very rarely land there and are very important, but rather that rich people land there to get a burger next door whenever they want.
>If it starts happening too often and the residents don't think they're getting a good deal, they can increase the fee.
I don't see how more money makes you sleep better at night when the rich private plane owner is flying over your house most nights.
> when they do it was because it was really worth it to them
But this is totally unrelated to why the thing was banned in the first place. We don't ban things out of a moral concern that the perpetrators haven't fully considered their lives and decided what's really important to them, we ban things because we don't want them to happen.
I also disagree that "I am willing to pay a lot of money" has any correlation with "this action is worth a lot to me". To make that relationship work, the fine would have to be set at "whatever you personally consider to be a lot of money".
> The large fee compensates local residents in the form of reduced city taxes over time.
I wish lowering the taxes by compensating with other means was a more common approach. The most usual approach is accumulating income in whatever way possible.
Isn't this in part because so many cities need all the cash they can get to fund individually-insolvent infrastructure? [0] If the goal is to be able to maintain roads that can't pay for themselves by enabling revenue generation, then I can absolutely see why cities would need to accumulate income in whatever way possible.
What types of activities does this apply to and where does it not apply? Just for the sake of argument, could this also apply to something like murder? i.e. if you wanted to murder somebody, you can do so only if you pay a super high fee otherwise go to prison. If you pay the fee, it must be worth it to you.
It already practically does. You just pay the fee to sufficiently high-powered lawyers. Or spend the money to incorporate, where your actions can be divorced from the consequences and maybe you pay whatever the actuarial cost of a human life is.
> It's usually better to have a high fee for things you don't want people to do rather than outright banning something.
Even better is putting a high fee on things normal people have to do, so that you can continue to finance friends and family in the nomenklatura and make sure they afford everything that pleases them.
I've witnessed two political decisions that led to no cars on the roads (the UK fuel strike 23 years ago, and the COVID lockdowns), and in both cases they made the sub/urban environment better immediately.
As soon as batteries or whatever can replace hydrocarbon engines for the average person, then sure $160US/gallon or whatever.
For a long time I have casually suggested a fuel tax that goes up by a dime per gallon per month, and just keeps increasing at that rate until the situation improves. It would take years for America to equal the OECD average fuel tax at that pace.
The idea of "increase fuel tax 1% each month that our country emits more capita carbon than the world average, and decrease them 1% if we emit less" would seem like a very sensible law.
But alas, very few laws use that kind of structure - not only in the USA, but anywhere in the world, and not just for environmental stuff, but for any regulated thing.
Instead lawmakers seem to prefer to see some problem, make some move, and then if the problem still exists repeat the process.
I don't really understand the aversion to 'automation' of that loop.
You are going to need to grandfather users of existing used cars if you don't want a mob with pitchforks and torches. Even when electric cars are affordable on average its necessary to understand the effect on price and value that would be caused by changing incentives. There are around 250 million fossil fuel cars on the road and $160/gallon fuel taxes would make those cars value effectively go to zero while sending electric cars price to the moon.
Even if scaled in over time to avoid breaking the economy you would have a long tail of cheap used cars which would be difficult for users to up and replace owned by those least likely to be able to absorb the shock.
You have folks commuting in a $5000 car for 10 years for which $20,000 would be a financial death sentence. There are plenty of folks who absolutely need a car to be able to work and continually keep an older used car for a LOT less than average.
Not all of these folks could even get a car loan for a compliant car so you would be basically telling them to go fuck themselves.
It makes more sense to simply mandate phasing out manufacturing or importing new gas powered consumer cars and let cars age out rather than using extreme gas taxes as a lever.
You would direct the revenue from the tax into grants for those least able to upgrade to electric on their own. London is doing such a scrappage scheme right now for the latest increase in emissions standards.
Causing car prices to increase post-recession was kind of the point of cash for clunkers, but I don’t see why something more targeted has to have the same effect.
No cars on the roads works for short periods of time, but with 15 million people living in e.g. the London metro, you need something to move 15 million people's worth of living logistics (food, goods for sale, garbage removal, etc.). Those are all carried by wheeled vehicles, whether it be cars, vans, or lorries. The niceties of the suburban or urban areas aren't possible without them.
Even if they were all electric or powered by unicorn farts or whatever, it's still millions of multi-ton steel vehicles zipping around leaving as much trace as a multi-ton moving thing would. I grant you at least the air quality would be better without internal combustion.
In the end, all Europe is filled with cute little walkable towns, yet people still congregate to the congested, filthy, car-filled metros, for some reason. And at a certain level of built-up population density, you just can't have a very nice natural environment; the brief moments of peace you observed during the Covid lockdowns or whatever can't last, because that would mean the city itself dies.
It's also dishonest to not include an answer for personal transportation. "Public transit" is a handwavy answer, since obviously if personal transportation means are removed, more public transit will be needed, meaning more vehicles (be it trains, buses, or taxis) will be on the road.
Unless your solution is that people should just move less?
To be fair, if people just stayed in their houses and didn't use electricity or water and stopped eating and just died when they ran out of food then we could have the whole CO2 problem wrapped up for a good 1,000 years or so in about 40-60 days, assuming they also took the time to gracefully shut down any operating machinery and safely disposed of any hazardous chemicals while waiting for their impending death.
Humanity might go extinct in the process, but they would have at least stopped further destroying the only planet they have to live on in the process.
GP just pulled a number out of the air. You could have just said it was disproportionate to the actual cost of concrete rather than reacting emotionally. I was surprised to learn concrete is only $130/ton, I thought it would be a lot more.
It doesn't really have anything to do with the price of concrete, though. It has to do with the price of carbon. If valuing carbon captured in concrete at $5000 per ton, the equivalent emissions tax on burning carbon is absurdly high.
It's a skill we all need to learn if we are to avoid completely missing the actual point and getting focused on the least important aspect of what somebody said.
I was curious what it would actually be. Assuming a full offset with expensive direct air capture of CO2 ($238 / tonne [0]), the carbon tax would only be $2.12 per gallon for 8,887 grams CO2 [1].
Capturing the carbon is only part of the cost... The other part is sequestering it for millions of years. Concrete is a great place to do that, where many other 'sequestering' techniques might only last tens or hundreds of years, requiring the capture fee be paid again and again and again.
Regular concrete is about $130/ton. Concrete products like decorative paving can cost $1500/ton installed. Specialist carbon-free concrete for those would cost $1500 + $200 = $1700. An 11% surcharge doesn't seem an unreasonable for choosing to do something the 'hurt the environment' way - anything less and I suspect many would say 'nah, don't bother'.
Because coffee grounds would actually make terrible aggregate, as complex organic and formerly alive compounds, there's a lot of potential for weird chemical breakdown that could harm the concrete or anything else in the concrete.
Char is pretty chemically stable, because carbon is very chemically stable.
Should be a tax break per percentage of carbon up to the safe limit. Same with corporate taxes. Corporations should receive a progressive tax break for their lowest-paid employee's salary. The higher the lower the tax.
An alternative to taxing or fees, is to allow the free market to utilize the capital that would have gone to fees to further advance our understanding and capabilities. The technological advances lost due to onerous fees across industries could be keeping us in a CO2 producing scenario.
Taxes on pollution are by far the most direct and effective way to motivate the free market to work on the pollution problem. It shouldn't be a collection of ad-hoc taxes and subusidies; it should be a flat carbon tax equal to the global harm that the carbon does, coupled with a market in offsets.
Hoping the market will solve this problem without imposing reasons for it to do so is basically how we got here in the first place.
> Hoping the market will solve this problem without imposing reasons for it to do so is basically how we got here in the first place.
Humans inherently seek technological advancements. We have been extracting CO2 from the environment from our very beginnings. Cheap energy allows us to do more research and development to escape the carbon dependency. Fees could potentially incentivize the right person at the right time to develop an escape. Depending on that is as much a hope as I have for free market incentives. We're both hoping here.
> is to allow the free market to utilize the capital that would have gone to fees to further advance our understanding and capabilities
What was stopping the 'free market' from utilizing that capital to further advance our understanding and capabilities? Before 'onerous fees', how many large-scale polluters were taking some of their profits and investing in researching how to reduce CO2?
>Before 'onerous fees', how many large-scale polluters were taking some of their profits and investing in researching how to reduce CO2?
Here is one example:
>Patent records reveal oil companies actively pursued research into technologies to cut carbon dioxide emissions that cause climate change from the 1960s – including early versions of the batteries now deployed to power electric cars such as the Tesla.
And ExxonMobil funded a disinformation campaigned aimed at discrediting scientists and blocking government efforts to fight climate change for more than 50 years, before publicly disavowing climate denial in 2008.
Another quote that ages well:
We in the petroleum industry are convinced that by the time a practical electric car can be mass produced and marketed, it will not enjoy any meaningful advantage from an air pollution standpoint,” he told Congress. “Emissions from internal-combustion engines will have long since been controlled.”
I don’t think that we should trust companies to act against their best interest just because “capitalism” is a magic word.
Why didn’t they spend more profits on research? Why did they lobby against pollution reduction if they’re so advanced? Why did they invent emission reduction technology in 1960, but in 2023 we have a massive pollution problem? The last 60 years could be a thesis to prove your entire premise as flawed. This is proof that they can’t be trusted with their profits, nor their research results.
Are we talking about pollution or CO2? Pollution from vehicles is largely controlled. It is not perfect by any means. CO2 is not pollution. It is a necessary component of plant growth and animal life.
> Why did they lobby against pollution reduction
For the same reasons I mentioned previously. Arbitrary fees and regulations can stifle the natural advancement. The patent in this case shows that they were working on reducing CO2 emissions which would benefit them in the long run as ICE engines would be cleaner. As such, they would be better competition to future electric competitors. Hence, more oil being purchased for their bottom line.
If they spend money and time lobbying and paying fees, that is money that is not spent on productive activities. Furthermore, it costs consumers more to purchase their product. This cost to consumers restricts their ability to invest in themselves and their future. Little Johnny wants to go to school to study clean nuclear fusion? Too bad, Ma & Pa have been paying more for goods and services for 18 years. Little Johnny will have to flip burgers instead.
C02 isn't a pollutant insofar as any amount being a pure negative but too much of it is obviously negative. This is a distinction that nobody including the parent poster or you are confused about.
The free market might over time get us cleaner engines when interests align but in all honestly the biggest factor driving cleaner engines has always been regulation and the next logical step for that regulation is to move towards forbidding the manufacture of new gas powered consumer vehicles which we can likely accomplish by the 2030s with regulation.
If too much money is spent lobbying we could very well make the productive part of that equation where money changes hands illegal, watch it become vastly less effective, and watch companies investment in same spin down quickly.
>The free market might over time get us cleaner engines when interests align but in all honestly the biggest factor driving cleaner engines has always been regulation...
One scientist learned that smog was a result of automobile emissions as early as 1948 (https://en.wikipedia.org/wiki/Arie_Jan_Haagen-Smit). That was 56 years after automobiles were first produced. Shortly thereafter, the Federal government started tackling the issue in 1955 (https://www.epa.gov/clean-air-act-overview/evolution-clean-a...). Why would companies invest in cleaner emissions if the government was going to make mandates that would throw a wrench in their investments? It has been better for them to wait and see what they have to do. They were never given the chance to self regulate.
Fortunately all of history exists and we can look at the fact that where regulation wasn't imposed and see that the majority who were most willing to foist high external costs on society were able to out compete any minority that behaved more admirably and most markets tend to end up dominated by a few players nearly exclusively from the less ethical fellows as even a small initial advantage is magnified because higher profits in one cycle provide a successively higher advantage in future cycles. Economists have been explaining why this is for literally centuries. Markets don't handle externalities without external regulation. Despite centuries of examples we still have folks asking for "self regulation" which we know doesn't work.
Companies have and will kill thousands of people to have slightly more money.
> One scientist learned that smog was a result of automobile emissions as early as 1948 .... That was 56 years after automobiles were first produced. Shortly thereafter ... in 1955 .... They were never given the chance to self regulate.
and... the cynic in me thinks that the purpose of that research would be to lock it up and prevent anyone from using it, vs actually deploying it and reducing emissions.
> The technological advances lost due to onerous fees across industries could be keeping us in a CO2 producing scenario
This seems quite backwards. If there is no incentive or motivating market stimulus, then there is no reason for any company to invest it research anything outside of what makes them the most money. We already know that these companies will not spend capital in those ways, because they already did not do so in the time periods before the associated taxes and fees existed. And to do so without be dereliction of what their shareholders expected and wanted them to do.
>If there is no incentive or motivating market stimulus
Is the depletion of oil and gas reserves not enough incentive? They will not last forever. In the grand scheme of things it is a small amount of time before we have to convert to nuclear, solar, hydro, and wind or start burning trees en masse again. As the resources are depleted, the price will go up due to limited supply. That price increase will spur R&D.
Tragedy of the commons is precisely what I have used to argue that prices will go up because the resources are being depleted. In this case, oil/gas is being over harvested by the individual. However, other energy sources are relatively infinite. Oil/gas happens to be cheap right now, but in the future it will not be. As the price rises, there becomes a greater incentive to seek other sources.
> As the price rises, there becomes a greater incentive to seek other sources.
This is not a valid or reliable mechanism for correcting misaligned incentives. It may occur by happenstance but is not guaranteed to happen prior to significant damage to the commons. The point of a carbon tax is to create a direct mechanism that corrects incentives in the presence of market failure. I would suggest this article:
We've tried that approach. It doesn't work because many people are greedy and will redirect capital towards marketing efforts to increase their own profit in the short term.
So, the "coffee" in this study is an intentional clickbait red herring. It goes through pyrolysis, meaning it isn't ground up coffee anymore, it's just carbon.
You will get this effect likely from any plant matter that gets ground up before it goes through pyrolysis.
Volcanic ash is glass (the stone melts during an eruption due to the heat, then explodes into millions of splinters as clouds which lock down air travel because it melts again in the engines and destroys them) and can be found thousand of kilometers away afterean eruption (e.g. Yosemite eruption), creating a deadly environment for every animal where it's falling down.
Pyrolysis isn't exactly burning stuff, it's carbonizing it by heating without access to air. So no, it's not the same as wood ash because it's not ash.
Wood ash isn't carbon. It's mostly remnant minerals like sodium, potassium, and calcium after the carbon has burned away (hence "potash" = "pot ash" as potassium's namesake).
The proper comparison here would be charcoal.
(Volcanic ash, on the other hand, contains common rock-forming elements: silicon, magnesium, and iron, with the proportions depending on the type of volcano.)
I'm fairly sure coffee grounds are the most valuable "waste" that we regularly throw out. Some time ago I found out how obscenely good it is for starting plant growth, and it's great for a million less obvious things too, now even making concrete!
That's extra good because apparently we're running out of high quality sand for making concrete.
I keep my grounds but I've found whenever I use them on indoor plants it grows mould on it within a day of watering the soil. Outside plants / veg don't have this issue -- have you come across this before? I keep my used grounds in a conservatory, they're very dry when I use them, although I guess not dry enough...
grounds are fantastic in an active composting environment. they make really great, nutrient-rich soil. less so for indoor plants with their tiny, relatively sterile environment. Indoor plants usually suffer from two problem wrt coffee grounds: a "that's going to mould," problem and a "that's too acidic on it's own to be useful," problem.
How old is your soil? Mixing in some fresh soil with the grounds might be a solution since a lot of the micro-organisms in soil that would break that down and eat the mold degrade over time.
i live in an arid climate and just air-dry and then put them in a container for later use. however i also only use it as part of the soil for outdoor gardens. my grandmother’s “recipe” was topsoil, sheep manure, coffee grounds, and banana peels and that’s worked out for me too
> apparently we're running out of high quality sand for making concrete.
Sand for concrete is increasingly obtained by crushing of hard rocks like granite (manufactured sand or M-sand); this can have superior properties to the previously used natural concrete sand.
I live on a 6 acre hobby 'farm' and have had a huge garden in the ground in my own native sandy loam here... but the only good pepper plants I've ever managed to grow were grown in partially composted coffee grinds mixed about 50% with sand... in pots.
But that was when I worked at the Google Waterloo office and could get as much a quantity of grinds as I wanted from the cafe there. Wish I still had access to that. 1 day of grinds was a 5 gallon bucket!
Every coffee shop I've worked at had someone who would come by and pick up the grounds every few days. It was always clearly just some guy who had a never-commented-on-or-explained arrangement with the owner, rather than like a company using it for commercial compost. You might be able to ask around and get a similar thing going?
Also even years later I strongly believe that, somehow, a trash can full of espresso grinds is the heaviest material in the world. Shit's denser than lead idk.
We’ve been able to just call up the local Starbucks’ and usually at least one is happy to give theirs, last time we went 4/4 and got more than we knew what to do with.
Tangential: TIL (OK, I knew but had forgotten) that aerobic composting of organic material — e.g., kitchen food waste — produces significantly less methane (an especially-bad greenhouse gas) than just dumping the waste in a landfill where it degrades anaerobically and the lack of oxygen results in more methane. [0]
Which makes me feel better about scattering our daily coffee grounds onto the lawn and in the garden beds — the grounds will decompose aerobically and are reportedly good for the soil, and with the grounds scattered, the paper filters take up less space in our kitchen-counter composting bucket and bag. (Brewing coffee with a paper filter reduces the grounds' acidity, which can matter for some types of plant.) [1]
Relatedly: For $10 per month, residents of our little enclave city can have their kitchen food waste picked up curbside each week and taken to a local-ish composting facility. The pickup truck used to pick up the compost is gasoline-fueled, but it's a start, and it's far more convenient than DIY composting. We've been subscribing to that service for a couple of years and have found that we don't fill up trash bags to put out for curbside pickup as often, so there's a small win there as well. Maybe other locales will start to do likewise? [2]
In the SF Bay Area, we are required to put food waste in our "green" organics can which is the same used garden trimmings etc. There is no fee associated with either our organics or recycling cans. Instead, the fee structure is based around the size of our landfill can, so we reduce our subscription fee by selecting a smaller can.
I also dump coffee grounds onto our garden, but I put eggshells in with it. Unfortunately our garden is tiny and mainly concrete, so it's only really a couple of flower beds which are now virtually buried in a testament to how much coffee I get through.
It wasn’t obvious to me from the bullet points, but apparently the pyrolysis eliminates the organic compounds in the SCG that hinder the hydration reaction.
Bio waste is best waste there is because what we need is whatever material we extract from the fields to go back there to fertilise it. Anything that we extract from the soil that isn't going back there is essentially eroding it.
Having a choice to mine more sand or destroy biological material to make buildings, I would prefer to mine more sand and leave the biological material to be available to cycle through the environment.
I have no data about the ecological cost of using spent coffee grounds, but I do suspect collecting, shipping, processing it (pyrolysis!) is going to cost way more than using sand in bulk.
By rough order of magnitude I don't see how this is any more than a fun fact with no commercial relevance. 4 billion tonnes of concrete are used annually and only 10 million tonnes of coffee. Even if you could gather up all of the grounds you'd still barely put a dent in the concrete production.
Unless the strength benefits result in lighter structures using less concrete. Though I suspect a lot of the use of concrete require the dead weight of concrete more than the strength (think of a gravity dam for example).
But I think the idea was more about what to do with the 10 million tonnes of coffee to help the environment than how to replace 2 or 3 billion tonnes of filler necessary to create concrete.
I guess that is another way of looking at it. However, with the pyrolysis step and the cost of collection I still don't see how it helps. A busy coffee shop produce perhaps 10kg of waste a day and the big players already have ways of recycling it.
> Bio waste is best waste there is because what we need is whatever material we extract from the fields to go back there to fertilise it. Anything that we extract from the soil that isn't going back there is essentially eroding it.
But if that waste was going to a landfill instead of "the fields", then isn't it better if it gets put to a productive use rather than an unproductive one?
If you can somehow collect coffee grounds to make cement, you can also collect is as part of generic biological waste fraction and use it as a fertiliser.
I happen to use coffee grounds (yes, we make a lot of espresso at home) and we already use spent coffee grounds as natural fertiliser. It improves the soil for some of the plants, improves aeration, attracts earthworms.
Getting the thousands of independent cafes to donate the grinds and have a way to collect them is going to be a challenge either way. Maybe the concrete option adds enough $ value to make it worth someone to go around and collect them.
No, not if the cost to extract it from the normal disposal process is more than the benefits. Also, a good amount of spent coffee grounds simply end up flushed out as wastewater.
I get where you are coming from, and some careful calculations are needed. But it's important to note this isn't replacing sand, it increasing the strength, you need 30% less concrete if it's 30% stronger.
The energy needed to extract sand and gravel from the ground, the logistics around moving heavy bulk material, crushing and preparing it, uses a staggeringly large amount of fuel. This is potentially up to 30% saving on that energy use.
I think what you are missing is perspective. What you are not seeing is the piles of grounds that would be needed and the tangle of logistics to get the grounds from where they are produced to where they can be used.
Why do you think lifting and transporting 1t of grounds takes less energy than lifting and transporting 1t of sand?
Only sand is already conveniently placed in bulk and very dense and does not require pyrolysis to be usable, etc. Almost every process related to sand I can imagine (I am not an expert at making cement in volume) will cost more for coffee grounds.
> What you are not seeing is the piles of grounds that would be needed and the tangle of logistics to get the grounds from where they are produced to where they can be used.
so many of these ideas seem to hand wave over “we’ll need to implement a whole new waste stream worldwide. don’t mind that we can hardly manage >1 stream as it is”
Our current supply chain almost always buried waste in landfills, unfortunately. Landfills are not expected to be used for agriculture almost ever because of contamination with all sorts of waste, heavy metals, etc. (I think a serious decontamination effort would be needed). Of course, it would be good if organic waste was separated and returned to the environment.
I've also been wondering about soil depletion. What we do today is use fertilizers, which can be extracted from the ocean or air as Nitrogen, Phosphorus and Potassium, they're not expected to be depleted ever (and they're the basic elements needed for plants, along with CO2). However I don't know the situation of other micronutrients, such as iron, selenium (well known to vegans), copper, etc. (copper is already very difficult and costly to extract). It shouldn't be impossible to fertilize micronutrients as well, but that's going to be an additional cost and difficulty to agriculture in the future.
In regards to this being eco-friendly or not, it really depends, and most likely a 30% reduction in concrete usage would be well worth it, even with soil depletion taken into account. As a senior internet citizen though, I'm skeptical of those claims, specially with large numbers as those (you see one of those every now and then...).
Again, I think it is important to remember WHAT exactly are we comparing.
I am not comparing a) throwing coffee grounds into landfill, to b) using coffee grounds for cement.
I am comparing a) collecting coffee grounds and use them as a fertiliser, vs b) collecting coffee grounds and using them as an ingredient for cement.
Essentially, if you can collect coffee grounds for cement you can also collect them for all sorts of other uses. What I am saying is that, once you went through the trouble of collecting coffee grounds, there are better ways than to use them for cement.
If this helps to reduce the quantity of concrete used that can only be a good thing. The cement industry is responsible for 8% of all green house gas emissions and an enormous quality of particulates in the atmosphere, we really need to use less concrete!
I wander if there are other food waste products that can also be used? It would be awesome if they found somethings that was a waste product from food mass-production, something what is available in bulk with simple logistics.
It's probably not replacing the cement though -- it's almost certainly an additive in the concrete mixture, like flyash. And even if it does make the mixture stronger, there are lots of variables for that, like aggregate strength, water/cement ratio, curing times, temperatures, additives and admixtures.
Glossary for the people here who haven't taken classes from people really particular about it:
* Cement is the 'glue' part
* Concrete is Cement + small aggregate (sand) + large aggregate (gravel)
* Cement doesn't dry, it cures, and the water becomes bound in gels between the cementitious minerals. If it does dry out (due to fire, or prior to curing), it loses its strength.
* The trucks aren't cement mixers, they're concrete mixers.
Cool OT sidenote about this. I live in an adobe house, and I wondered for a long time what the difference is between concrete blocks and adobe bricks, in terms of their physico-chemical structure. Adobe has comparable compressive strength to concrete blocks, but unlike concrete will dissolve in water. I always found this a bit mysterious.
Turns out that the most significant difference is that in concrete (or any cementitious material), the important molecular bonds are covalent. In adobe the bonds are ionic.
Consequently, adding water to adobe easily disrupts the structure by interfering with the ionic bonds (just as it when salt dissolves in), but does essentially nothing to the covalent bonds in concrete.
Even cooler, perhaps, is that as the wet adobe dries out again, the same bonds will reform, and you get back to the original state again.
> Historically, it was extracted from the ashes of plants grown in sodium-rich soils. Because the ashes of these sodium-rich plants were noticeably different from ashes of wood (once used to produce potash), sodium carbonate became known as "soda ash".[12][full citation needed] It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide
Sadly, we also need to use less coffee, since the increase in coffee consumption in Asia is about to cause an explosion in tropical forest land re-use ...
100% agree. our buildings should be built out of what ever material makes them best suited for ... being a building. as far as eliminating 'organic waste', I really don't care about that at all.
The only thing I care about is, does it make better concrete that is economically feasible?
you just spent a bunch of energy heating old organic waste
If the heat generated by the curing process in concrete is suffice then you get that for free. Better in fact, because you're making waste heat useful.
I'm not really worried about a damp, finely ground, organic substance like coffee beans being sent to landfills. This is actually a good thing, as it catalyzes bacteria, mold, fungi, and yeasts to initiate decomposition.
...which releases methane (CH4) into the atmosphere since it is in an anaerobic atmosphere. And then the cycle is no longer the neutral CO2 -> coffee bean -> CO2 but it added CH4 to the atmosphere which heats the planet.
Ideally all bio waste is industrially composted and the generated CH4 used to generate electricity and heat, but sequestering it is also okay.
I'm willing to bet that this works with nearly any carbon product. Coffee grounds was just a good one for the news headlines because it is something nearly everyone recognises as a non-toxic waste product.
If this happens commercially, it will probably use coal dust, municipal waste dust, sawdust or some other cheap carbon-containing thing.
The article quotes them describing a range of biochar souce materials:
> “Our research team has gained extensive experience in developing highly optimised biochars from different organic wastes, including wood biochar, food-waste biochar, agricultural waste biochar, and municipal solid-waste biochar, for concrete applications,”
But it doesn't actually say anything about coffee biochar in comparison to any other biochar. Is this a setup to be a research mill where we'll get the same press release every month but next with sugarcane bagasse biochar, corn cob biochar, grain chaff biochar etc etc? Or is it possible to develop some general understanding of "irrespective of source, biochar with grain sizes in x range, and y percentage of carbon and z percentage minerals used in proportion w in concrete yields a product with compressive strength ~f(w, x, y, z)"
We need to stop using concrete as a building material: there are enormous numbers of alternatives and the vast majority of them use a fraction of the carbon during their lifecycles.
For instance, lime stabilised soil has been used in large civil engineering projects for decades. Lime has been used as a render and a cement for thousands of years and if extracted from limestone sensibly minimises emissions to a fraction of those from concrete.
(This post written from the Centre for Alternative Technology, on lunch while I am on a course learning how to build houses out of load bearing straw bales)
Lime isn't really all that different from cement -- it's made by baking the CO2 out of limestone, historically using charcoal kilns (also not very CO2 friendly).
There's a company commercializing lime obtained from silicates. The process involves acid dissolution of the silicate, then conversion of the chlorides to oxides by high temperature reaction with steam (releasing the chlorine in hydrogen chloride, which is then recycled back to dissolve more silicates.)
That wasn't specified. It can be done without fossil fuels, of course. If I understand correctly, it doesn't require more heat energy than the conventional process starting from limestone.
Yes, that's the main point, the stronger concrete. If you make stronger concrete it will last longer and you thus will need less of it in the long run.
Concrete production is very bad for environment, so the less we need to make the better.
And Australia: know for insane coffee
consumption (has to be freshly ground!)
and appartments with “concrete cancer” although that may not be solved by this.
The worry is that biodegradation generates greenhouse gases. So if we avoid coffee waste from biodegrading, we avoid bacteria from producing greenhouse gases.
Might people be freaking out too much about this stuff?
Last time I checked carbon was black. Mixing it with cement to get a darker concrete may be a brain dead idea: you get CO2 sequestration and warmer walls/pavements etc if exposed to sunlight.
One can avoid that by using it only for no sun exposed elements, but it does complicate things.
Basically they're converting the coffee grounds into biochar, which is know to strengthen concrete (you can add less cement for the same strength). A company in France will soon sell this biochar-reinforced concrete. I suppose other companies will do so too.
Specific sands are needed for specific purposes, and sometimes they can be a challenge logistically. Further, on human time scales, sand is a non-renewable resource:
Sand is cheaper per kilo than used coffee grounds.
"Building-grade sand" is sharp sand. It is the cheapest sand you can buy. Roman's built things out of their concrete which was full of random bits of rubble, and some of these structures still stand today.
Correction: they used lime mortar. Modern concrete was created about a century and a half ago. The random bits were chunks of lime which increased the building's hydraulic qualities - lime self heals, concrete doesn't
I'm all for locking carbon away in solid objects, and this seems like a good way. One might imagine a law that says "all new cement products must be at least 20% carbon by weight, or pay a $1000/ton tax for missing carbon".
That incentivises locking up carbon in structures, in a form unlikely to escape anytime soon, and gives a proportional fee for anyone who doesn't wish to do so (for example, concrete for very specialist purposes).