I find this a weird framing. I mean, sure, it’ll release co2 as it decomposes… but that’s a pretty natural process? Like, regardless of whether or not it’s processed into coffee for drinking the...
Spent coffee grounds (SCG) are the most wasteful byproduct of the entire coffee industry. By one estimate, 60 million pounds of the stuff ends up in landfills around the world. If that wasn’t bad enough, as organic material decomposes, it gives off methane and carbon dioxide—two no good, very bad gasses that are driving climate change.
I find this a weird framing. I mean, sure, it’ll release co2 as it decomposes… but that’s a pretty natural process? Like, regardless of whether or not it’s processed into coffee for drinking the berries will decompose at some point. That’s how life works.
Presumably the coffee trees that the coffee industry plant produce more oxygen than the decomposition of its fruit…
Yeah, it's a pretty common issue when it comes to this stuff; viewing individual processes in a complete vaccum. all biological matter releases Co2 when it decomposes. Plants take carbon in via...
Yeah, it's a pretty common issue when it comes to this stuff; viewing individual processes in a complete vaccum.
all biological matter releases Co2 when it decomposes. Plants take carbon in via respiration, then use that carbon as the foundation of all the organic molecules that make up its biomass, then release that carbon when they die, either into the ground, or into the air as part of the respiratory cycle of de composers. It's like saying "planting trees is bad for the environment, because eventually when they die, they'll release all that carbon into the atmosphere.
The issue is releasing carbon that was sequestered from the atmosphere by being locked underground as part of fossil fuels, not the natural carbon cycle.
Additionally, the carbon in coffee grounds is WAY easier to deal with than the carbon in the atmosphere. If you buried coffee grounds deep enough underground where it can't easily decompose, that carbon would effectively be removed from the carbon cycle, lowering the amount of carbon in the atmosphere (coffee plants ingest carbon via respiration, their beans are roasted and used to make coffee, then those spent grounds are sequestered), so effectively they could be a carbon sink.
Also... like, most of the biomass of a coffee plant isn't the beans inside the cherries. The rest of the entire plant also decomposes, so saying "spent coffee grounds are the most wasteful byproduct of the entire coffee industry" on the basis that they decompose, when you have an entire rest of the plant that is 95% of the weight of those beans is just... nonsensical.
I have the same issue with critiques of the beef industry on the basis of methane emissions from cows. Like, yes, it is a problem because methane is a better insulator than Co2, but also, that carbon didn't magically appear in cow's bellies. All of the carbon that a cow burbs will eventually be reabsorbed into the plants it eats. So the problem is real, but it's not nearly as dire as constantly unlocking carbon that's been sequestered for thousands or millions of years underground.
The problem is that, while methane eventually breaks down into co2, in the mean time it disproportionately heats the atmosphere causing other co2 or methane sinks to be released. So the methane...
The problem is that, while methane eventually breaks down into co2, in the mean time it disproportionately heats the atmosphere causing other co2 or methane sinks to be released. So the methane subsequently does cause the release of sequestered carbon sources.
I think Popular Mechanics' article frames this discovery as a purely eco-friendly alternative. Compare the bullet points of the article and the bullet points of the research paper. RMIT...
I think Popular Mechanics' article frames this discovery as a purely eco-friendly alternative. Compare the bullet points of the article and the bullet points of the research paper. RMIT researchers put the use of waste coffee grinds as a "plus" at the bottom, almost to say "all this and a bag of chips."
Being able to use less sand (the right kind of sand for cement is not that easy to source) while simultaneously increasing compression rating by 30%, and with something so readily available is the real win here. The fact that it may or may not offer any CO2 emission offset is at best, a cherry on top of it all.
I welcome this as great news and win win for everyone.
Incidentally thats why the adage of 'mixing clay and sandy soils makes cement' is flawed. You can tremendously improve nutrient quality of soil by adding clay soil, and improve drainage of clay...
Incidentally thats why the adage of 'mixing clay and sandy soils makes cement' is flawed.
You can tremendously improve nutrient quality of soil by adding clay soil, and improve drainage of clay soil with sand. There are risks to be sure, but tis true of most things.
Ok, so they're heating coffee grounds to a pretty high temperature (600 or 900 degrees) and turning them to char. What's the environmental impact of that process compared to just letting them...
Ok, so they're heating coffee grounds to a pretty high temperature (600 or 900 degrees) and turning them to char. What's the environmental impact of that process compared to just letting them decompose?
Yeah they kinda glossed over that part. This process of Pyrolysis is new to me, but it sounds like it breaks down organic compounds into smaller one without oxygen … so presumably it doesn’t...
Yeah they kinda glossed over that part. This process of Pyrolysis is new to me, but it sounds like it breaks down organic compounds into smaller one without oxygen … so presumably it doesn’t result in CO2 generation? If this is a form of carbon sequestration, then the next question would be how much co2 is emitted by the energy generation required to fuel the pyrolysis?
Between 100 and 500 °C, many common organic molecules break down. Most sugars start decomposing at 160–180 °C. Cellulose, a major component of wood, paper, and cotton fabrics, decomposes at about 350 °C.[3] Lignin, another major wood component, starts decomposing at about 350 °C, but continues releasing volatile products up to 500 °C.[3] The decomposition products usually include water, carbon monoxide CO and/or carbon dioxide CO2, as well as a large number of organic compounds.[4][15]
I was more so assuming that they would end up using some kind of fossil fuel to get to the 600-900 degrees needed for this process, and would be interested to know if the impact burning of the...
I was more so assuming that they would end up using some kind of fossil fuel to get to the 600-900 degrees needed for this process, and would be interested to know if the impact burning of the fuel would exceed the impact of just letting the coffee decompose naturally.
I see that as independent of this, though. Those emissions are going to happen regardless of the destination of the grounds because nobody is going to grow and process coffee just for this use...
I see that as independent of this, though. Those emissions are going to happen regardless of the destination of the grounds because nobody is going to grow and process coffee just for this use case. The coffee is being ground and brewed for consumption completely independent of this process.
Sorry, I wasn't particularly clear in my off-the-cuff response. I think making concrete stronger is great, as is contributing to making it more ecologically friendly. My point was more centered on...
Sorry, I wasn't particularly clear in my off-the-cuff response.
I think making concrete stronger is great, as is contributing to making it more ecologically friendly. My point was more centered on the first R in "Reduce, Reuse, Recycle".
The coffee grounds part of this research seems like it's just pulled out as the "hey laymen, look at this weird thing the scientists said!". If there's a concern that the waste from a product is causing environmental damage, the first target should be to use less of it. Also coffee is probably pretty far down the list of food items that produce CO2 emissions, so the framing of this is weird on 2 fronts.
Anyways, this is a relatively minor nit on my part. The research itself is interesting, I'd be more interested in learning what other types of organic waste could be put through pyrolisis for the same purpose.
If they are burning it to char, does it actually matter if it's coffee? Could you just use wood pellets burnt to char? Or vegetable scraps? Actually now that I think of it, don't they sometimes...
If they are burning it to char, does it actually matter if it's coffee? Could you just use wood pellets burnt to char? Or vegetable scraps?
Actually now that I think of it, don't they sometimes use fly ash in concrete for this purpose?
There are probably other alternatives, but I think the advantage is that these spent coffee grounds are a waste product that we can find a use for in this way.
There are probably other alternatives, but I think the advantage is that these spent coffee grounds are a waste product that we can find a use for in this way.
The research paper talks about related prior work. There is more on fly ash, recycled silica, slag, etc as well.
The research paper talks about related prior work.
Similar results in the improvement in compressive-strength results with the addition of wood biochar have been reported by Tan et al. (2021) and Gupta et al. (2018); however, they used wood biochar material as a very low percentage of cement replacement material.
There is more on fly ash, recycled silica, slag, etc as well.
I wonder if the same effect would work with ferrock. I read a thing on it that used a formulation of 60% iron dust 20% silica and 10% each of fly ash and metakaolin. Maybe the fly ash could be...
I wonder if the same effect would work with ferrock. I read a thing on it that used a formulation of 60% iron dust 20% silica and 10% each of fly ash and metakaolin. Maybe the fly ash could be swapped with coffee?
Iron dust I think is just an industrial byproduct, silica could maybe come from recycled glass, coffee grounds from coffee houses, and I don't really know where metakaolin comes from.
That's a cool idea, but ... So, assuming those are both annual figures, and assuming if we could somehow (how?) collect and process all coffee grounds from all land fills globally, that would...
That's a cool idea, but ...
60 million pounds of the stuff ends up in landfills around the world. [...] concrete used in construction projects relies on extracting 55 billion tons of natural sand
So, assuming those are both annual figures, and assuming if we could somehow (how?) collect and process all coffee grounds from all land fills globally, that would replace ~0.000002 % of the sand. That's irrelevant even if my math is off by several orders of magnitude.
If I understand correctly, construction quality sand for concrete is getting harder to find. It's possible this process could be used with other material besides coffee. It's also possible we just...
Yes, maybe someone finds a way to substitute the coffee with grass or saw dust or other biological waste products. That would be amazing. I'm convinced there is no alternative to building less,...
Yes, maybe someone finds a way to substitute the coffee with grass or saw dust or other biological waste products. That would be amazing.
I'm convinced there is no alternative to building less, regarless of the climate impact of concrete. Construction needs lots of dense energy. Recharging your excavator batteries 30 % of the time is going to slow things down.
I find this a weird framing. I mean, sure, it’ll release co2 as it decomposes… but that’s a pretty natural process? Like, regardless of whether or not it’s processed into coffee for drinking the berries will decompose at some point. That’s how life works.
Presumably the coffee trees that the coffee industry plant produce more oxygen than the decomposition of its fruit…
Yeah, it's a pretty common issue when it comes to this stuff; viewing individual processes in a complete vaccum.
all biological matter releases Co2 when it decomposes. Plants take carbon in via respiration, then use that carbon as the foundation of all the organic molecules that make up its biomass, then release that carbon when they die, either into the ground, or into the air as part of the respiratory cycle of de composers. It's like saying "planting trees is bad for the environment, because eventually when they die, they'll release all that carbon into the atmosphere.
The issue is releasing carbon that was sequestered from the atmosphere by being locked underground as part of fossil fuels, not the natural carbon cycle.
Additionally, the carbon in coffee grounds is WAY easier to deal with than the carbon in the atmosphere. If you buried coffee grounds deep enough underground where it can't easily decompose, that carbon would effectively be removed from the carbon cycle, lowering the amount of carbon in the atmosphere (coffee plants ingest carbon via respiration, their beans are roasted and used to make coffee, then those spent grounds are sequestered), so effectively they could be a carbon sink.
Also... like, most of the biomass of a coffee plant isn't the beans inside the cherries. The rest of the entire plant also decomposes, so saying "spent coffee grounds are the most wasteful byproduct of the entire coffee industry" on the basis that they decompose, when you have an entire rest of the plant that is 95% of the weight of those beans is just... nonsensical.
I have the same issue with critiques of the beef industry on the basis of methane emissions from cows. Like, yes, it is a problem because methane is a better insulator than Co2, but also, that carbon didn't magically appear in cow's bellies. All of the carbon that a cow burbs will eventually be reabsorbed into the plants it eats. So the problem is real, but it's not nearly as dire as constantly unlocking carbon that's been sequestered for thousands or millions of years underground.
The problem is that, while methane eventually breaks down into co2, in the mean time it disproportionately heats the atmosphere causing other co2 or methane sinks to be released. So the methane subsequently does cause the release of sequestered carbon sources.
I think Popular Mechanics' article frames this discovery as a purely eco-friendly alternative. Compare the bullet points of the article and the bullet points of the research paper. RMIT researchers put the use of waste coffee grinds as a "plus" at the bottom, almost to say "all this and a bag of chips."
Being able to use less sand (the right kind of sand for cement is not that easy to source) while simultaneously increasing compression rating by 30%, and with something so readily available is the real win here. The fact that it may or may not offer any CO2 emission offset is at best, a cherry on top of it all.
I welcome this as great news and win win for everyone.
Incidentally thats why the adage of 'mixing clay and sandy soils makes cement' is flawed.
You can tremendously improve nutrient quality of soil by adding clay soil, and improve drainage of clay soil with sand. There are risks to be sure, but tis true of most things.
Ok, so they're heating coffee grounds to a pretty high temperature (600 or 900 degrees) and turning them to char. What's the environmental impact of that process compared to just letting them decompose?
Yeah they kinda glossed over that part. This process of Pyrolysis is new to me, but it sounds like it breaks down organic compounds into smaller one without oxygen … so presumably it doesn’t result in CO2 generation? If this is a form of carbon sequestration, then the next question would be how much co2 is emitted by the energy generation required to fuel the pyrolysis?
https://en.m.wikipedia.org/wiki/Pyrolysis
I was more so assuming that they would end up using some kind of fossil fuel to get to the 600-900 degrees needed for this process, and would be interested to know if the impact burning of the fuel would exceed the impact of just letting the coffee decompose naturally.
And on top of that, what about the CO2 emissions from the entire production chain of the coffee in the first place?
I see that as independent of this, though. Those emissions are going to happen regardless of the destination of the grounds because nobody is going to grow and process coffee just for this use case. The coffee is being ground and brewed for consumption completely independent of this process.
Sorry, I wasn't particularly clear in my off-the-cuff response.
I think making concrete stronger is great, as is contributing to making it more ecologically friendly. My point was more centered on the first R in "Reduce, Reuse, Recycle".
The coffee grounds part of this research seems like it's just pulled out as the "hey laymen, look at this weird thing the scientists said!". If there's a concern that the waste from a product is causing environmental damage, the first target should be to use less of it. Also coffee is probably pretty far down the list of food items that produce CO2 emissions, so the framing of this is weird on 2 fronts.
Anyways, this is a relatively minor nit on my part. The research itself is interesting, I'd be more interested in learning what other types of organic waste could be put through pyrolisis for the same purpose.
If they are burning it to char, does it actually matter if it's coffee? Could you just use wood pellets burnt to char? Or vegetable scraps?
Actually now that I think of it, don't they sometimes use fly ash in concrete for this purpose?
There are probably other alternatives, but I think the advantage is that these spent coffee grounds are a waste product that we can find a use for in this way.
The research paper talks about related prior work.
There is more on fly ash, recycled silica, slag, etc as well.
I wonder if the same effect would work with ferrock. I read a thing on it that used a formulation of 60% iron dust 20% silica and 10% each of fly ash and metakaolin. Maybe the fly ash could be swapped with coffee?
Iron dust I think is just an industrial byproduct, silica could maybe come from recycled glass, coffee grounds from coffee houses, and I don't really know where metakaolin comes from.
That's a cool idea, but ...
So, assuming those are both annual figures, and assuming if we could somehow (how?) collect and process all coffee grounds from all land fills globally, that would replace ~0.000002 % of the sand. That's irrelevant even if my math is off by several orders of magnitude.
If I understand correctly, construction quality sand for concrete is getting harder to find. It's possible this process could be used with other material besides coffee. It's also possible we just need to build less. https://www.cnbc.com/2021/03/05/sand-shortage-the-world-is-running-out-of-a-crucial-commodity.html
Yes, maybe someone finds a way to substitute the coffee with grass or saw dust or other biological waste products. That would be amazing.
I'm convinced there is no alternative to building less, regarless of the climate impact of concrete. Construction needs lots of dense energy. Recharging your excavator batteries 30 % of the time is going to slow things down.