11 ms·

Chemists discover new way to harness energy from ammonia

62 points by theduder99 5y ago

inter_netuser 5y ago
Well, at least now we'll know about an accident upwind without needing to look.
gus_massa 5y ago
In case you are wondering, the molecule at the top is 2-Pyrroline https://en.wikipedia.org/wiki/Pyrroline https://en.wikipedia.org/wiki/Pyrroline and as far as I can see it's totally unrelated to the reaction discussed in the article.
- xhkkffbf 5y ago
  Exactly. I was wondering what was going on because I remember enough chemistry to know that ammonia is not a ring. I would have been less confused if I was totally clueless. As the Pope said, a little knowledge is a dangerous thing.
  - gus_massa 5y ago
    In the graphical abstract and the figure of the research paper, they have the molecules that are actually involved https://www.nature.com/articles/s41557-021-00797-w https://www.nature.com/articles/s41557-021-00797-w In the graphical abstract, the two ruthenium atoms are in the center, and the ammonia makes a temporary bound on top of them. They are surrounded by two organic molecules.
robthebrew 5y ago
"If the reaction were housed in a fuel cell where ammonia and ruthenium react at an electrode surface, it could cleanly produce electricity without the need for a catalytic converter." If the ruthenium is not a catalytic converter, then what is it? A god particle?
- gus_massa 5y ago
  I agree, it's confusing/misleading/wrong. Anyway, I interpret is as: "This reaction does not produce Nitric Oxide, so it's not necessary pass the exhaust though a catalytic converter like the ones that car have."
  - deleted 5y ago
    [deleted]
- AtlasBarfed 5y ago
  Maybe they mean "no Platinum"
- lambdatronics 5y ago
  Phys.org reporting is not great. Most methods for using ammonia in fuel cells rely on high-temperature catalysts to convert ammonia back to hydrogen, possibly in a separate unit from the fuel cell or else inside the fuel cell itself, if the fuel cell already runs at high temperature. These folks are claiming to have a room-temperature catalyst that can be part of a fuel cell that uses ammonia directly.
- muaytimbo 5y ago
  They most likely proved this out in solution, this is speculation that a ruthenium coated electrode would produce current.
bryanlarsen 5y ago
> "One of the next challenges I would like to think about is how to generate ammonia from water, instead of hydrogen gas," Trenerry says. "The dream is to put in water, air and sunlight to create a fuel." Producing ammonia from water is a lot easier than producing it from natural gas the way it's currently done now. The drawback is that it requires a lot more energy. There are 6 steps in the process here: https://en.wikipedia.org/wiki/Ammonia_production https://en.wikipedia.org/wiki/Ammonia_production If you use water & electricity & air as the feedstock, it's a 2 step process: 1: electrolysize water to produce H2 2: Haber-Bosch 3 H2 + N2 → 2 NH3 (In practice step 1 is multiple steps of purification and adding electrolytes) In many situations, it's cheaper to convert hydrogen to ammonia, transport the ammonia, then convert back than it is to transport hydrogen. That's exactly what Korean steelmakers are doing to source green hydrogen: https://www.kedglobal.com/newsView/ked202107160003 https://www.kedglobal.com/newsView/ked202107160003
- neltnerb 5y ago
  Being able to use ammonia as a fuel to produce electricity is really neat to me because an ammonia fuel cell uses a liquid fuel, unlike a hydrogen fuel cell, and so is far more energy dense (including storage cylinder weight). It might be a better way to handle energy storage than batteries, honestly, if we didn't make the ammonia from fossil fuels...
  - WalterBright 5y ago
    If ammonia is made from natural gas, what happens to the carbon?
    - ncmncm 5y ago
      Oxidized for heat to drive the process.
      - WalterBright 5y ago
        So it's still emitting the same CO2.
xyzzy21 5y ago
Ammonia is like hydrogen - not a fuel source but merely a fuel storage medium. Further we used to common use ammonia for refrigeration before Freon became a thing - the reason we don't use it for that except in very limited large scale applications, is that it's SUPER POISONOUS and prone to leaking and killing. So pushing ammonia is another example of solving one problem but creating 5-10 more problems which our society ALREADY KNOWS WILL HAPPEN - because we've been there before and abandoned it for safety, economic and environmental reasons. It's willful ignorance of history and science.
- p1mrx 5y ago
  If ammonia is safe enough for agricultural use, then it may also be sensible for other large-scale applications, like powering ships and industrial processes. You definitely wouldn't want it in your car though.
  - Turing_Machine 5y ago
    Well, gasoline isn't exactly a benign substance, either. It would be interesting to compare the number of people burned to death in gasoline fires to those poisoned by ammonia vapor. My gut tells me that gasoline is currently responsible for more fatalities, but I don't have any hard facts on that. Of course the number of ammonia deaths would go up to some degree if it were used in cars, but that would be offset by fewer gasoline deaths.
  - AngryData 5y ago
    If by safe you mean one of the things farmers fear the most in an already dangerous job. Even as a kid working around farm equipment, silos, and all sorts of dangerous chems, I was warned to stay far away from any ammonia tanks, and farmers are never having a good time when they are hauling a tank of it. Tank full of pesticide? "Yeah go ahead and put some in a pop bottle and mix it with random shit you find in the barn and throw bugs in it" An ammonia tank? "Don't even go near it, especially if it is being used or being hauled."
- jabl 5y ago
  If we're gonna have an energy economy based on nitrogen fuels, I'd vote for the even spiffier hydrazine. What could possibly go wrong?
lambdatronics 5y ago
From the abstract[0]: they have a promising catalyst that could be used for a "direct ammonia fuel cell" operating at room temperature. It involves ruthenium, which is an expensive rare earth element. For context, it's possible to 'crack' ammonia into hydrogen and nitrogen & feed that to a PEM fuel cell, but this requires extra equipment, high temperatures, and consumes some of the output energy. Solid oxide fuel cells can also run directly on ammonia, but that's b/c they operate at high temperature [650 C].[1] Solid acid fuel cells can turn ammonia into hydrogen at 250 C -- but this is still extra equipment & consumes energy.[2] Ammonia can also be burned in modified gas turbines, which IMO would be a great way to quickly displace natural gas in peaker plants, to enable higher renewables penetration w/o relying on fossil fuels to take up the slack. Ammonia is a better hydrogen carrier than liquid or compressed hydrogen because storage is easier due to high energy density. The round-trip energy efficiency could also be higher.[3] It's less flammable, but more toxic. For more, see [4]. It sounds like the real enabling technology would be direct fuel cells and direct electrosynthesis (reverse fuel cells) to get higher efficiency. [0] https://www.nature.com/articles/s41557-021-00797-w https://www.nature.com/articles/s41557-021-00797-w [1] https://www.ammoniaenergy.org/articles/ammonia-for-fuel-cells-afc-sofc-and-pem/ https://www.ammoniaenergy.org/articles/ammonia-for-fuel-cell... [2] https://news.northwestern.edu/stories/2020/11/ammonia-to-green-hydrogen/ https://news.northwestern.edu/stories/2020/11/ammonia-to-gre... [3] https://www.ammoniaenergy.org/articles/round-trip-efficiency-of-ammonia-as-a-renewable-energy-transportation-media/ https://www.ammoniaenergy.org/articles/round-trip-efficiency... [4]https://www.intechopen.com/chapters/40233 https://www.intechopen.com/chapters/40233
- R0b0t1 5y ago
  I think this is an interesting development for smaller generating needs, maybe even personal, but: > Ammonia can also be burned in modified gas turbines, which IMO would be a great way to quickly displace natural gas in peaker plants, to enable higher renewables penetration w/o relying on fossil fuels to take up the slack. Nukes can operate as peaker plants. The feedback from the control rods is nearly instantaneous. It's just in some markets they must telegraph their moves and get approval, which can take ~4 hours or more. I bring up nukes because how are we going to make the ammonia? Nitrogen fixing reactions take loads of power. You could get it from nukes until we figure out higher capacity solar collection, but I don't know of anything else that would work well.
throwaway743 5y ago
Excuse my ignorance, but could this possibly lead to an energy source powered by animal waste/urine?
- Turing_Machine 5y ago
  I don't think the ammonia concentrations are high enough to make it cost-effective. There's a reason why commercial ammonia is produced from petroleum rather than being extracted from animal waste. If you wanted to use animal waste, you'd probably be better off fermenting it into methane (that definitely works, and is actually used as a power source in some specialized situations).
- AngryData 5y ago
  Could it? Yes. Will it? Never, it is worth far too much as fertilizer even when artificial fertilizer is relatively cheap. It is like running a wood fired power plant on antique furniture.
- dredmorbius 5y ago
  There's not enough biomass production in the entire US to provide an alternative to present fossil fuel consumption. Even highly optimistic proposals to replace a small fraction of petroleum consumption (aviation fuel) with biofuels would require an area equivalent to much of the central plains states. And that's about 6% of net fuel use. Wastestream energy flows are, by definition, a subset of the net input. Estimates I've seen are for about 1/3 of net energy input being available from waste-streams, though that's usually focused on solid waste. Urine production is based on protein breakdown (urea), which as a nutrient is typically 10-30% of net calories. Even before digging further, the net total resource would be fairly small. Not entirely insignificant, but given costs of collection and processing ... probably unrewarding.
dredmorbius 5y ago
If you can produce synthetic ammonia without fossil fuel (natural gas) inputs, you can create synthetic hydrocarbon analogues of petroleum-based petrol (gasoline), kerosene (jet fuel), diesel, and possibly heavier grades of oil (marine bunker fuel). Though it's worth noting that the latter are used not so much for their suitability in marine use as their unsuitability elsewhere, and lighter grades (kerosene or diesel) would be likely substitutes. Ammonia is harmful or deadly when inhaled, produces a large quantity of NOx in normal combustion (TFA specifically addresses this one point), and is highly corrosive. It's one of the five most harmful chemicals in regular use already, given limited industrial and agricultural applications. As a general-application fuel, particularly in scenarios in which fuel-based power systems cannot readibly be substituted (marine and aviation uses) would greatly increase hazards of such operations. Synthetic fuels are lossy as all heck in round-trip energy return (on the order of 15--25% recovery as motive or generation output), but offer a very-well-understood, well-behaved, largely safe, and high-energy-density (by both weight and volume) option for very-long-term (100+ million years proved) energy storage. There's very little else that fits that bill. Fossil fuels are principally nonviable going forward due to net CO2 emissions. Synthetic fuels based on ocean or atmospheric CO2 extraction would be net-neutral. Costs are higher than present fossil fuels, but present fossil fuels are grossly mis-priced based on both pollution and cost-of-formation externalities excluded from present market prices. (The pricing error could be as high as millions of times --- markets can in fact be remarkably inefficient and inaccurate.) Other externalities including localised polluton (NOx, CO, VOCs, particulates) would remain an issue, but can be reasonably well controlled with extant technologies. If net fuel usage is decreased through electrified transportation and changes in land-use, lifestyle, architectural, and industrial behaviours, use in shipping, aviation, mobile, and remote applications should be within reason. Ammonia not so much.
- WalterBright 5y ago
  > markets can in fact be remarkably inefficient and inaccurate The markets are working efficiently, is it prices in the costs that apply. In order for pollution to be taken into account, the cost of that has to be applied. The most efficient and simplest way to do this is with a tax. Tax fuels based on the carbon content.
betwixthewires 5y ago
I like talk of fuel cells, alternate energy storage mediums and all that. But there's always the question of where the energy comes from. All energy we use comes from the sun. Every single drop of it. For a billion years plankton and algae were sequestered from the biosphere and converted to the explosive energy "source" we use now to allow for our population and standard of living, this is petroleum, but the energy came from the sun. We are lucky. Even wind, which is fluid current, is caused by convection from energy that originated in the sun. Hydroelectric is water rushing downwards, that was moved upwards by the sun evaporating water. Even fission is energy in elements that was stores there from fusion in the sun. So where do you get the energy from? The entire earth needs energy from the sun for the biosphere to continue. You aren't going to get the energy you got from it slowly accumulating over a billion years, waiting for us to find it, not without paving the earth in solar panels. Short of sending a dyson swarm to collect solar energy from the vast surface area of the sun that does not radiate onto the earth directly, you're not going to get an energy source that is more environmentally friendly than burning petroleum, because you have to pave the natural landscape just to get a miniscule percentage of what tectonic activity accrued on our behalf for a billion years. This is what people who talk about carbon neutral and environmentally friendly energy fail to grasp. There is energy out there that isn't oil, but it requires more disruption to natural ecosystems than burning oil, and it is far less energy dense. The best thing that can be done is to use oil to launch solar panels into orbit around the sun and somehow send that energy here, what you're ultimately doing is creating a lens to concentrate solar radiation to earth in a round about way. Bar that, you're talking about eradicating a significant portion of the human population.
- robbedpeter 5y ago
  Just to pick nits, the sun is not the source of our heavy elements. Those came from other stellar phenomena, elsewhere in the galaxy. All of the iron on earth came from supernovae of red supergiant stars. Gold requires much higher energy and some comes from neutron star collisions. Nucleosynthesis of heavy elements requires more energy, and thus more energetic or more massive stars as they get heavier. Through cosmic eons, as stars produce these elements and get exploded, smeared, or otherwise diffused into clouds of elemental ions, the heavy elements coalesce into asteroids that are then captured by the gravity of other stellar systems. Early in the solar system's formation, the heavy elements in asteroids served as seeds around which the lighter elements were attracted. When earth (and other planets) were at their present mass and orbital configuration, there was a period of heavy bombardment, in which asteroids smashed into the surface, depositing nearly all of the heavy elements which humans have access to. Our nuclear energy comes from supernovae from almost half the age of the universe ago (6 bn years.) The radioactive elements in the earth contribute about half of the heat at the surface, the remainder of which comes from the sun. Geothermal is actually partially nuclear energy. Cosmochemistry is wild! https://world-nuclear.org/information-library/nuclear-fuel-cycle/uranium-resources/the-cosmic-origins-of-uranium.aspx https://world-nuclear.org/information-library/nuclear-fuel-c...

62 points by theduder99 5y ago

Well, at least now we'll know about an accident upwind without needing to look.

In case you are wondering, the molecule at the top is 2-Pyrroline https://en.wikipedia.org/wiki/Pyrroline https://en.wikipedia.org/wiki/Pyrroline and as far as I can see it's totally unrelated to the reaction discussed in the article.

xhkkffbf 5y ago
Exactly. I was wondering what was going on because I remember enough chemistry to know that ammonia is not a ring. I would have been less confused if I was totally clueless. As the Pope said, a little knowledge is a dangerous thing.
- gus_massa 5y ago
  In the graphical abstract and the figure of the research paper, they have the molecules that are actually involved https://www.nature.com/articles/s41557-021-00797-w https://www.nature.com/articles/s41557-021-00797-w In the graphical abstract, the two ruthenium atoms are in the center, and the ammonia makes a temporary bound on top of them. They are surrounded by two organic molecules.

robthebrew 5y ago

"If the reaction were housed in a fuel cell where ammonia and ruthenium react at an electrode surface, it could cleanly produce electricity without the need for a catalytic converter." If the ruthenium is not a catalytic converter, then what is it? A god particle?

gus_massa 5y ago
I agree, it's confusing/misleading/wrong. Anyway, I interpret is as: "This reaction does not produce Nitric Oxide, so it's not necessary pass the exhaust though a catalytic converter like the ones that car have."
- deleted 5y ago
  [deleted]
AtlasBarfed 5y ago
Maybe they mean "no Platinum"
lambdatronics 5y ago
Phys.org reporting is not great. Most methods for using ammonia in fuel cells rely on high-temperature catalysts to convert ammonia back to hydrogen, possibly in a separate unit from the fuel cell or else inside the fuel cell itself, if the fuel cell already runs at high temperature. These folks are claiming to have a room-temperature catalyst that can be part of a fuel cell that uses ammonia directly.
muaytimbo 5y ago
They most likely proved this out in solution, this is speculation that a ruthenium coated electrode would produce current.

bryanlarsen 5y ago

> "One of the next challenges I would like to think about is how to generate ammonia from water, instead of hydrogen gas," Trenerry says. "The dream is to put in water, air and sunlight to create a fuel." Producing ammonia from water is a lot easier than producing it from natural gas the way it's currently done now. The drawback is that it requires a lot more energy. There are 6 steps in the process here: https://en.wikipedia.org/wiki/Ammonia_production https://en.wikipedia.org/wiki/Ammonia_production If you use water & electricity & air as the feedstock, it's a 2 step process: 1: electrolysize water to produce H2 2: Haber-Bosch 3 H2 + N2 → 2 NH3 (In practice step 1 is multiple steps of purification and adding electrolytes) In many situations, it's cheaper to convert hydrogen to ammonia, transport the ammonia, then convert back than it is to transport hydrogen. That's exactly what Korean steelmakers are doing to source green hydrogen: https://www.kedglobal.com/newsView/ked202107160003 https://www.kedglobal.com/newsView/ked202107160003

neltnerb 5y ago
Being able to use ammonia as a fuel to produce electricity is really neat to me because an ammonia fuel cell uses a liquid fuel, unlike a hydrogen fuel cell, and so is far more energy dense (including storage cylinder weight). It might be a better way to handle energy storage than batteries, honestly, if we didn't make the ammonia from fossil fuels...
- WalterBright 5y ago
  If ammonia is made from natural gas, what happens to the carbon?
  - ncmncm 5y ago
    Oxidized for heat to drive the process.
    - WalterBright 5y ago
      So it's still emitting the same CO2.

xyzzy21 5y ago

Ammonia is like hydrogen - not a fuel source but merely a fuel storage medium. Further we used to common use ammonia for refrigeration before Freon became a thing - the reason we don't use it for that except in very limited large scale applications, is that it's SUPER POISONOUS and prone to leaking and killing. So pushing ammonia is another example of solving one problem but creating 5-10 more problems which our society ALREADY KNOWS WILL HAPPEN - because we've been there before and abandoned it for safety, economic and environmental reasons. It's willful ignorance of history and science.

p1mrx 5y ago
If ammonia is safe enough for agricultural use, then it may also be sensible for other large-scale applications, like powering ships and industrial processes. You definitely wouldn't want it in your car though.
- Turing_Machine 5y ago
  Well, gasoline isn't exactly a benign substance, either. It would be interesting to compare the number of people burned to death in gasoline fires to those poisoned by ammonia vapor. My gut tells me that gasoline is currently responsible for more fatalities, but I don't have any hard facts on that. Of course the number of ammonia deaths would go up to some degree if it were used in cars, but that would be offset by fewer gasoline deaths.
- AngryData 5y ago
  If by safe you mean one of the things farmers fear the most in an already dangerous job. Even as a kid working around farm equipment, silos, and all sorts of dangerous chems, I was warned to stay far away from any ammonia tanks, and farmers are never having a good time when they are hauling a tank of it. Tank full of pesticide? "Yeah go ahead and put some in a pop bottle and mix it with random shit you find in the barn and throw bugs in it" An ammonia tank? "Don't even go near it, especially if it is being used or being hauled."
jabl 5y ago
If we're gonna have an energy economy based on nitrogen fuels, I'd vote for the even spiffier hydrazine. What could possibly go wrong?

lambdatronics 5y ago

From the abstract[0]: they have a promising catalyst that could be used for a "direct ammonia fuel cell" operating at room temperature. It involves ruthenium, which is an expensive rare earth element. For context, it's possible to 'crack' ammonia into hydrogen and nitrogen & feed that to a PEM fuel cell, but this requires extra equipment, high temperatures, and consumes some of the output energy. Solid oxide fuel cells can also run directly on ammonia, but that's b/c they operate at high temperature [650 C].[1] Solid acid fuel cells can turn ammonia into hydrogen at 250 C -- but this is still extra equipment & consumes energy.[2] Ammonia can also be burned in modified gas turbines, which IMO would be a great way to quickly displace natural gas in peaker plants, to enable higher renewables penetration w/o relying on fossil fuels to take up the slack. Ammonia is a better hydrogen carrier than liquid or compressed hydrogen because storage is easier due to high energy density. The round-trip energy efficiency could also be higher.[3] It's less flammable, but more toxic. For more, see [4]. It sounds like the real enabling technology would be direct fuel cells and direct electrosynthesis (reverse fuel cells) to get higher efficiency. [0] https://www.nature.com/articles/s41557-021-00797-w https://www.nature.com/articles/s41557-021-00797-w [1] https://www.ammoniaenergy.org/articles/ammonia-for-fuel-cells-afc-sofc-and-pem/ https://www.ammoniaenergy.org/articles/ammonia-for-fuel-cell... [2] https://news.northwestern.edu/stories/2020/11/ammonia-to-green-hydrogen/ https://news.northwestern.edu/stories/2020/11/ammonia-to-gre... [3] https://www.ammoniaenergy.org/articles/round-trip-efficiency-of-ammonia-as-a-renewable-energy-transportation-media/ https://www.ammoniaenergy.org/articles/round-trip-efficiency... [4]https://www.intechopen.com/chapters/40233 https://www.intechopen.com/chapters/40233

R0b0t1 5y ago
I think this is an interesting development for smaller generating needs, maybe even personal, but: > Ammonia can also be burned in modified gas turbines, which IMO would be a great way to quickly displace natural gas in peaker plants, to enable higher renewables penetration w/o relying on fossil fuels to take up the slack. Nukes can operate as peaker plants. The feedback from the control rods is nearly instantaneous. It's just in some markets they must telegraph their moves and get approval, which can take ~4 hours or more. I bring up nukes because how are we going to make the ammonia? Nitrogen fixing reactions take loads of power. You could get it from nukes until we figure out higher capacity solar collection, but I don't know of anything else that would work well.

throwaway743 5y ago

Excuse my ignorance, but could this possibly lead to an energy source powered by animal waste/urine?

Turing_Machine 5y ago
I don't think the ammonia concentrations are high enough to make it cost-effective. There's a reason why commercial ammonia is produced from petroleum rather than being extracted from animal waste. If you wanted to use animal waste, you'd probably be better off fermenting it into methane (that definitely works, and is actually used as a power source in some specialized situations).
AngryData 5y ago
Could it? Yes. Will it? Never, it is worth far too much as fertilizer even when artificial fertilizer is relatively cheap. It is like running a wood fired power plant on antique furniture.
dredmorbius 5y ago
There's not enough biomass production in the entire US to provide an alternative to present fossil fuel consumption. Even highly optimistic proposals to replace a small fraction of petroleum consumption (aviation fuel) with biofuels would require an area equivalent to much of the central plains states. And that's about 6% of net fuel use. Wastestream energy flows are, by definition, a subset of the net input. Estimates I've seen are for about 1/3 of net energy input being available from waste-streams, though that's usually focused on solid waste. Urine production is based on protein breakdown (urea), which as a nutrient is typically 10-30% of net calories. Even before digging further, the net total resource would be fairly small. Not entirely insignificant, but given costs of collection and processing ... probably unrewarding.

dredmorbius 5y ago

If you can produce synthetic ammonia without fossil fuel (natural gas) inputs, you can create synthetic hydrocarbon analogues of petroleum-based petrol (gasoline), kerosene (jet fuel), diesel, and possibly heavier grades of oil (marine bunker fuel). Though it's worth noting that the latter are used not so much for their suitability in marine use as their unsuitability elsewhere, and lighter grades (kerosene or diesel) would be likely substitutes. Ammonia is harmful or deadly when inhaled, produces a large quantity of NOx in normal combustion (TFA specifically addresses this one point), and is highly corrosive. It's one of the five most harmful chemicals in regular use already, given limited industrial and agricultural applications. As a general-application fuel, particularly in scenarios in which fuel-based power systems cannot readibly be substituted (marine and aviation uses) would greatly increase hazards of such operations. Synthetic fuels are lossy as all heck in round-trip energy return (on the order of 15--25% recovery as motive or generation output), but offer a very-well-understood, well-behaved, largely safe, and high-energy-density (by both weight and volume) option for very-long-term (100+ million years proved) energy storage. There's very little else that fits that bill. Fossil fuels are principally nonviable going forward due to net CO2 emissions. Synthetic fuels based on ocean or atmospheric CO2 extraction would be net-neutral. Costs are higher than present fossil fuels, but present fossil fuels are grossly mis-priced based on both pollution and cost-of-formation externalities excluded from present market prices. (The pricing error could be as high as millions of times --- markets can in fact be remarkably inefficient and inaccurate.) Other externalities including localised polluton (NOx, CO, VOCs, particulates) would remain an issue, but can be reasonably well controlled with extant technologies. If net fuel usage is decreased through electrified transportation and changes in land-use, lifestyle, architectural, and industrial behaviours, use in shipping, aviation, mobile, and remote applications should be within reason. Ammonia not so much.

WalterBright 5y ago
> markets can in fact be remarkably inefficient and inaccurate The markets are working efficiently, is it prices in the costs that apply. In order for pollution to be taken into account, the cost of that has to be applied. The most efficient and simplest way to do this is with a tax. Tax fuels based on the carbon content.

betwixthewires 5y ago

I like talk of fuel cells, alternate energy storage mediums and all that. But there's always the question of where the energy comes from. All energy we use comes from the sun. Every single drop of it. For a billion years plankton and algae were sequestered from the biosphere and converted to the explosive energy "source" we use now to allow for our population and standard of living, this is petroleum, but the energy came from the sun. We are lucky. Even wind, which is fluid current, is caused by convection from energy that originated in the sun. Hydroelectric is water rushing downwards, that was moved upwards by the sun evaporating water. Even fission is energy in elements that was stores there from fusion in the sun. So where do you get the energy from? The entire earth needs energy from the sun for the biosphere to continue. You aren't going to get the energy you got from it slowly accumulating over a billion years, waiting for us to find it, not without paving the earth in solar panels. Short of sending a dyson swarm to collect solar energy from the vast surface area of the sun that does not radiate onto the earth directly, you're not going to get an energy source that is more environmentally friendly than burning petroleum, because you have to pave the natural landscape just to get a miniscule percentage of what tectonic activity accrued on our behalf for a billion years. This is what people who talk about carbon neutral and environmentally friendly energy fail to grasp. There is energy out there that isn't oil, but it requires more disruption to natural ecosystems than burning oil, and it is far less energy dense. The best thing that can be done is to use oil to launch solar panels into orbit around the sun and somehow send that energy here, what you're ultimately doing is creating a lens to concentrate solar radiation to earth in a round about way. Bar that, you're talking about eradicating a significant portion of the human population.

robbedpeter 5y ago
Just to pick nits, the sun is not the source of our heavy elements. Those came from other stellar phenomena, elsewhere in the galaxy. All of the iron on earth came from supernovae of red supergiant stars. Gold requires much higher energy and some comes from neutron star collisions. Nucleosynthesis of heavy elements requires more energy, and thus more energetic or more massive stars as they get heavier. Through cosmic eons, as stars produce these elements and get exploded, smeared, or otherwise diffused into clouds of elemental ions, the heavy elements coalesce into asteroids that are then captured by the gravity of other stellar systems. Early in the solar system's formation, the heavy elements in asteroids served as seeds around which the lighter elements were attracted. When earth (and other planets) were at their present mass and orbital configuration, there was a period of heavy bombardment, in which asteroids smashed into the surface, depositing nearly all of the heavy elements which humans have access to. Our nuclear energy comes from supernovae from almost half the age of the universe ago (6 bn years.) The radioactive elements in the earth contribute about half of the heat at the surface, the remainder of which comes from the sun. Geothermal is actually partially nuclear energy. Cosmochemistry is wild! https://world-nuclear.org/information-library/nuclear-fuel-cycle/uranium-resources/the-cosmic-origins-of-uranium.aspx https://world-nuclear.org/information-library/nuclear-fuel-c...