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This is exactly opposite of eco-friendly. Bio waste is best waste there is because what we need is whatever material we extract from the fields to go back ther

This is exactly opposite of eco-friendly. 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.

VBprogrammer 3y ago
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).
- onetimeuse92304 3y ago
  Of course. 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.
  - VBprogrammer 3y ago
    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.
jxf 3y ago
> 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?
- quickthrower2 3y ago
  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.
- onetimeuse92304 3y ago
  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.
- chrisco255 3y ago
  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.
samwillis 3y ago
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.
- onetimeuse92304 3y ago
  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.
  - sigstoat 3y ago
    > 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”
gnramires 3y ago
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...).
- onetimeuse92304 3y ago
  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.

VBprogrammer 3y ago

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).

onetimeuse92304 3y ago
Of course. 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.
- VBprogrammer 3y ago
  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.

jxf 3y ago

> 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?

quickthrower2 3y ago
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.
onetimeuse92304 3y ago
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.
chrisco255 3y ago
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.

samwillis 3y ago

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.

onetimeuse92304 3y ago
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.
- sigstoat 3y ago
  > 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”

gnramires 3y ago

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...).

onetimeuse92304 3y ago
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.