8 ms·

If I read this correctly, this is mostly aimed at the smoke-stacks of fossil fuel plants. Great for reducing their harm before we phase them out, and valuable e

by rocqua 4y ago

If I read this correctly, this is mostly aimed at the smoke-stacks of fossil fuel plants. Great for reducing their harm before we phase them out, and valuable especially if it is cheap enough to actually be plausible. Cheap here matter more than perfect, since the problem of emitting CO2 from fossil fuel plants is better (but more slowly) solved by phasing out fossil fuel. But how does this work for scrubbing CO2 from general atmosphere, is it anywhere close to an option? Once we have 'solved' the problem of no longer emitting CO2, we will almost certainly still have way more CO2 in the atmosphere than we want. Does this new scrubber material make it feasible to reduce the CO2 from the atmosphere, or will it be more economical to deal with the symptoms of high CO2 levels?

microjim 4y ago
Trees
- twawaaay 4y ago
  Trees do not reduce CO2 in long run. For starters, humanity emits more CO2 than the combined mass of entire biosphere (every living organism, not just trees), every 10 years. Even if we were somehow able to cover all landmasses of Earth with trees (which we can't) and thus double/triple the biomass we would only set back the problem by a decade or two. Second, trees are part of a cycle. They store the CO2 temporarily, then release it mostly back to the atmosphere -- very small part becomes soil. Trees are not a magical solution that is somehow constantly sequestering CO2 from atmosphere. Trees store a bit of CO2 once and then it stops and can even easily be reversed (if you burn it down). New growth is necessary to keep the store at the same level, otherwise the trees will burn or die and CO2 is returned to the atmosphere.
  - elmolino89 4y ago
    >For starters, humanity emits more CO2 than the combined mass of entire biosphere (every living organism, not just trees), every 10 years """ Plants and soils together currently absorb an estimated 30 percent of the CO2 emitted by human activities each year. """ https://news.stanford.edu/press/view/38728 https://news.stanford.edu/press/view/38728 Do you have source for your 10 years?
    - twawaaay 4y ago
      It is actually very simple. Everybody can check easily. You do not have to believe me. You need two numbers: 1. Amount of carbon emitted by humanity. The easiest way to get this is to find all production of coal, nat gas and oil and convert it to carbon. 2. Amount of carbon in biomass. You can find the estimate of weight of Earth's biomass online. Then you need to multiply by a factor of how much carbon there is in biomatter on average. All necessary numbers are readily available and not controversial. As to how much plants use CO2 it is IRRELEVANT. The only way it would be relevant is if you also had a number on how much plants emit CO2 back to atmosphere when they burn or rot. But this is extremely difficult to measure directly. Just as you can't figure out how much you are saving up just based on your income without knowing your expenses. But you do not have to estimate any of the two numbers. It is enough to imagine that, given constant weight of the biomass, all carbon converted from CO2 to biomass has also roughly equivalent release back to atmosphere one way or another.
elmolino89 4y ago
>Does this new scrubber material make it feasible to reduce the CO2 from the atmosphere, or will it be more economical to deal with the symptoms of high CO2 levels? The low tech solution for scrubbing C02 from the atmosphere is to get more plants absorbing it and prevent the plant decomposition back to CO2 or even worse to methane. Some of the agricultural waste may be just buried in the fields helping to build the organic matter in the soil, but it would be hard to avoid any CH4 emissions doing it. Just check any landfill with buried organic matter and some sipping in water. One can try to use pyrolysis and get charcoal. This would not be 100% emissions free (CO, CO2, CH4 etc.). The main problem with the above is that collecting wood/straw/etc. transporting and then processing it also requires energy, at least on land. Converting the millions of agro machines to run on batteries or hydrogen would not be carbon neutral either. Supposedly if we fertilize patches of the oceans the dead algae will nicely sink to the bottom not to be release CO2 for centuries.
- imhoguy 4y ago
  > if we fertilize patches of the oceans Don't we do it already with wastewater streaming down from fields, pipes, rivers...?
  - belorn 4y ago
    Yes, it is called eutrophication and is a huge pollution problem. The dead algae that drops to the ocean floor get eaten by bacteria and through that depletes the oxygen, resulting in hypoxic dead ocean. No fish and no plants, which in turn kills biodiversity both in and outside the water. Even if the goal was to store CO2 and we didn't care about anything else, the method has additional problems. With nothing living in dead zones except for algae, the methane gas produced by decomposing dead algaes has a high risk of rising to the surface.
  - elmolino89 4y ago
    Yes and no. Meaning: depositing fertilizer close to the shore in shallow waters causes toxic algal blooms and suffocates everything. One needs deep, cold waters so the sinking organic matter is not decomposing rapidly. And yes, if the winds blow the Saharan dust over large oceanic surfaces algae do grow in otherwise "desert" waters and some of the generated biomass does sink deep.
dools 4y ago
Scrubbing C02 is important for industrial processes other than energy production so it’s very important to get it right otherwise we can’t fabricate stuff without increasing emissions and building renewable infrastructure while adding another 3.5b people to the population is going to involve a lot of fabrication.
twawaaay 4y ago
> Cheap here matter more than perfect, since the problem of emitting CO2 from fossil fuel plants is better (but more slowly) solved by phasing out fossil fuel. The goal is to stop emitting CO2, not phasing out fossil fuels. If you can use fossil fuel without emitting CO2 (and other greenhouse gasses), then the goal is achieved. But we also know that fossil fuels are finite and it might be worthwhile to stop using them and learn to use alternatives before we get forced to do it when the sources run dry. For me the most tragic part of the current situation is that if we somehow destroyed our current civilisation, there would be no raw resources to support a new industrial age.
- ethbr0 4y ago
  If we somehow destroy our current civilization, then world population will plummet from starvation, especially in the third world that isn't fertilizer-self-sufficient. And we'll still have plenty of raw coal + recyclable metals.
  - twawaaay 4y ago
    We won't have any raw coal. All raw coal is hundreds of meters below ground because everything that was easily accessible was already dug. In my country hundreds of years ago people were gathering coal lying on the ground or picking it with a shovel in small holes. When oil was first found it was basically pooling on the surface or required a very shallow hole, nothing more than a deep water well, to reach. Not only those, but a lot of other easily available sources have already been completely used up. There might be some that are overlooked in very sparsely populated, hard to reach places like Russia, Brazil or Antarctica. But the same reason why they have not been found and exploited would be why a new attempt at civilisation will also have hard time trying to find it.
    - ethbr0 4y ago
      > All raw coal is hundreds of meters below ground because everything that was easily accessible was already dug. You should probably visit Wyoming. https://en.m.wikipedia.org/wiki/List_of_coal_mines_in_the_United_States https://en.m.wikipedia.org/wiki/List_of_coal_mines_in_the_Un...
brilee 4y ago
Good question. I was also suspicious of the angle/framing of the paper as a smokestack capture solution. My thoughts are 1. smokestacks are a great place to start, it's thermodynamically easier, has low-hanging fruit, and can be a stepping stone to a atmospheric DAC solution. 2. I bet that the smokestack angle of the paper is due to ALF being a decent oxygen absorber. The paper made the argument that the CO2 (diameter 330pm) vs. N2 (diameter 364pm) selectivity was due to size exclusion principles. But oxygen has diameter 346pm, much closer to CO2, so it would stand to reason that oxygen would compete for CO2 binding efficiency. If you read the supplementary materials/experimental conditions, literally every experiment is done under a protective flow of 99.95% N2 gas, indicating that this compound is not to be exposed to air.
- rocqua 4y ago
  Interesting angle. Even if this only works in smokestacks, it is hugely valuable. We will be stuck with some fossil fuel in the coming few years at least. Making those years less polluting is worthwhile. I suppose there is a risk that people say "we can do fossil fuel a bit longer, we scrub it now", but I think that will pretty soon be a clearly untenable position.
deleted 4y ago
[deleted]
ars 4y ago
> aimed at the smoke-stacks of fossil fuel plants "CO2 from dried CO2-containing gas streams" The word "dried" is going to cause trouble. Smoke stocks have a lot of water - more water than CO2 actually.
- angst_ridden 4y ago
  Yeah, and in gas/oil-fired electric turbines you typically inject a whole lot of water to create more mass going through. A power plant I worked at in the 90s tried to keep a 4:1 ratio of water to fuel oil. It was always amusing to explain to lay-folk that we "burned more water than oil," even if it wasn't technically precise.
- rocqua 4y ago
  The article states that the major advantage of this new material is much better resistance to water. Are you saying that the levels of water described in the paper are still way below untreated flue gasses?
  - ars 4y ago
    I don't know. I just saw the word "dried" and mentioned it. Flu gasses are majority water. Natural gas has twice as much water and co2 (by moles), and according to another poster they even inject additional water.

by rocqua 4y ago

microjim 4y ago

Trees

twawaaay 4y ago
Trees do not reduce CO2 in long run. For starters, humanity emits more CO2 than the combined mass of entire biosphere (every living organism, not just trees), every 10 years. Even if we were somehow able to cover all landmasses of Earth with trees (which we can't) and thus double/triple the biomass we would only set back the problem by a decade or two. Second, trees are part of a cycle. They store the CO2 temporarily, then release it mostly back to the atmosphere -- very small part becomes soil. Trees are not a magical solution that is somehow constantly sequestering CO2 from atmosphere. Trees store a bit of CO2 once and then it stops and can even easily be reversed (if you burn it down). New growth is necessary to keep the store at the same level, otherwise the trees will burn or die and CO2 is returned to the atmosphere.
- elmolino89 4y ago
  >For starters, humanity emits more CO2 than the combined mass of entire biosphere (every living organism, not just trees), every 10 years """ Plants and soils together currently absorb an estimated 30 percent of the CO2 emitted by human activities each year. """ https://news.stanford.edu/press/view/38728 https://news.stanford.edu/press/view/38728 Do you have source for your 10 years?
  - twawaaay 4y ago
    It is actually very simple. Everybody can check easily. You do not have to believe me. You need two numbers: 1. Amount of carbon emitted by humanity. The easiest way to get this is to find all production of coal, nat gas and oil and convert it to carbon. 2. Amount of carbon in biomass. You can find the estimate of weight of Earth's biomass online. Then you need to multiply by a factor of how much carbon there is in biomatter on average. All necessary numbers are readily available and not controversial. As to how much plants use CO2 it is IRRELEVANT. The only way it would be relevant is if you also had a number on how much plants emit CO2 back to atmosphere when they burn or rot. But this is extremely difficult to measure directly. Just as you can't figure out how much you are saving up just based on your income without knowing your expenses. But you do not have to estimate any of the two numbers. It is enough to imagine that, given constant weight of the biomass, all carbon converted from CO2 to biomass has also roughly equivalent release back to atmosphere one way or another.

elmolino89 4y ago

>Does this new scrubber material make it feasible to reduce the CO2 from the atmosphere, or will it be more economical to deal with the symptoms of high CO2 levels? The low tech solution for scrubbing C02 from the atmosphere is to get more plants absorbing it and prevent the plant decomposition back to CO2 or even worse to methane. Some of the agricultural waste may be just buried in the fields helping to build the organic matter in the soil, but it would be hard to avoid any CH4 emissions doing it. Just check any landfill with buried organic matter and some sipping in water. One can try to use pyrolysis and get charcoal. This would not be 100% emissions free (CO, CO2, CH4 etc.). The main problem with the above is that collecting wood/straw/etc. transporting and then processing it also requires energy, at least on land. Converting the millions of agro machines to run on batteries or hydrogen would not be carbon neutral either. Supposedly if we fertilize patches of the oceans the dead algae will nicely sink to the bottom not to be release CO2 for centuries.

imhoguy 4y ago
> if we fertilize patches of the oceans Don't we do it already with wastewater streaming down from fields, pipes, rivers...?
- belorn 4y ago
  Yes, it is called eutrophication and is a huge pollution problem. The dead algae that drops to the ocean floor get eaten by bacteria and through that depletes the oxygen, resulting in hypoxic dead ocean. No fish and no plants, which in turn kills biodiversity both in and outside the water. Even if the goal was to store CO2 and we didn't care about anything else, the method has additional problems. With nothing living in dead zones except for algae, the methane gas produced by decomposing dead algaes has a high risk of rising to the surface.
- elmolino89 4y ago
  Yes and no. Meaning: depositing fertilizer close to the shore in shallow waters causes toxic algal blooms and suffocates everything. One needs deep, cold waters so the sinking organic matter is not decomposing rapidly. And yes, if the winds blow the Saharan dust over large oceanic surfaces algae do grow in otherwise "desert" waters and some of the generated biomass does sink deep.

dools 4y ago

Scrubbing C02 is important for industrial processes other than energy production so it’s very important to get it right otherwise we can’t fabricate stuff without increasing emissions and building renewable infrastructure while adding another 3.5b people to the population is going to involve a lot of fabrication.

twawaaay 4y ago

> Cheap here matter more than perfect, since the problem of emitting CO2 from fossil fuel plants is better (but more slowly) solved by phasing out fossil fuel. The goal is to stop emitting CO2, not phasing out fossil fuels. If you can use fossil fuel without emitting CO2 (and other greenhouse gasses), then the goal is achieved. But we also know that fossil fuels are finite and it might be worthwhile to stop using them and learn to use alternatives before we get forced to do it when the sources run dry. For me the most tragic part of the current situation is that if we somehow destroyed our current civilisation, there would be no raw resources to support a new industrial age.

ethbr0 4y ago
If we somehow destroy our current civilization, then world population will plummet from starvation, especially in the third world that isn't fertilizer-self-sufficient. And we'll still have plenty of raw coal + recyclable metals.
- twawaaay 4y ago
  We won't have any raw coal. All raw coal is hundreds of meters below ground because everything that was easily accessible was already dug. In my country hundreds of years ago people were gathering coal lying on the ground or picking it with a shovel in small holes. When oil was first found it was basically pooling on the surface or required a very shallow hole, nothing more than a deep water well, to reach. Not only those, but a lot of other easily available sources have already been completely used up. There might be some that are overlooked in very sparsely populated, hard to reach places like Russia, Brazil or Antarctica. But the same reason why they have not been found and exploited would be why a new attempt at civilisation will also have hard time trying to find it.
  - ethbr0 4y ago
    > All raw coal is hundreds of meters below ground because everything that was easily accessible was already dug. You should probably visit Wyoming. https://en.m.wikipedia.org/wiki/List_of_coal_mines_in_the_United_States https://en.m.wikipedia.org/wiki/List_of_coal_mines_in_the_Un...

brilee 4y ago

Good question. I was also suspicious of the angle/framing of the paper as a smokestack capture solution. My thoughts are 1. smokestacks are a great place to start, it's thermodynamically easier, has low-hanging fruit, and can be a stepping stone to a atmospheric DAC solution. 2. I bet that the smokestack angle of the paper is due to ALF being a decent oxygen absorber. The paper made the argument that the CO2 (diameter 330pm) vs. N2 (diameter 364pm) selectivity was due to size exclusion principles. But oxygen has diameter 346pm, much closer to CO2, so it would stand to reason that oxygen would compete for CO2 binding efficiency. If you read the supplementary materials/experimental conditions, literally every experiment is done under a protective flow of 99.95% N2 gas, indicating that this compound is not to be exposed to air.

rocqua 4y ago
Interesting angle. Even if this only works in smokestacks, it is hugely valuable. We will be stuck with some fossil fuel in the coming few years at least. Making those years less polluting is worthwhile. I suppose there is a risk that people say "we can do fossil fuel a bit longer, we scrub it now", but I think that will pretty soon be a clearly untenable position.

deleted 4y ago

[deleted]

ars 4y ago

> aimed at the smoke-stacks of fossil fuel plants "CO2 from dried CO2-containing gas streams" The word "dried" is going to cause trouble. Smoke stocks have a lot of water - more water than CO2 actually.

angst_ridden 4y ago
Yeah, and in gas/oil-fired electric turbines you typically inject a whole lot of water to create more mass going through. A power plant I worked at in the 90s tried to keep a 4:1 ratio of water to fuel oil. It was always amusing to explain to lay-folk that we "burned more water than oil," even if it wasn't technically precise.
rocqua 4y ago
The article states that the major advantage of this new material is much better resistance to water. Are you saying that the levels of water described in the paper are still way below untreated flue gasses?
- ars 4y ago
  I don't know. I just saw the word "dried" and mentioned it. Flu gasses are majority water. Natural gas has twice as much water and co2 (by moles), and according to another poster they even inject additional water.