2 ms·

Thermodynamics is about energy not CO2, you can design negative CO2 devices and we even have proof in nature of that since that's what trees are doing.

wyager 5y ago
There are several conceptual issues here, but one of them is that trees require energy from sunlight to turn CO2 into other things.
- realusername 5y ago
  Yes but we don't have an energy problem, we have a CO2 problem and there's no law of physics preventing to absorb more CO2 than you emit.
  - diarrhea 5y ago
    That's true but assumes the captured CO2 remains that, captured. The article revolves around the idea of turning CO2 into fuel. Fuel which is burned, releasing that same CO2 again while having wasted a lot of intermediate energy. At best, that energy was renewable and would've been curtailed otherwise (hence wasted). Then you didn't "use energy" but it was still an utterly useless exercise. Now, if the carbon remains captured and the energy for capturing is renewable, we are in business. I'm not aware that is done on a meaningful scale yet though.
peteradio 5y ago
But thats not what this is. Fuel is intended to be consumed, seems like this is at best carbon neutral assuming totally neutral power source. Are our current power sources on average neutral or are they much more carbon positive?
- realusername 5y ago
  > But thats not what this is. Fuel is intended to be consumed, seems like this is at best carbon neutral assuming totally neutral power source Indeed, that's their goal, the issue is that currently we emit a lot so even making the fuel close to neutral (minus production inefficiencies) is already a huge progress. Going negative isn't for tomorrow unfortunately.
marginalia_nu 5y ago
The problem is that this requires reversing entropy. Turning CO2 into something that can burn into CO2 requires more energy than you get back while burning it, even in an optimal engine. This is true if humans reverse entropy or if trees do it.
- realusername 5y ago
  Economics are a different story yeah, there's no way to make carbone absorption economically possible without some carbon scheme designed by the country. They won't happen on their own that's for sure, that's where legislation should come in place.
- DennisP 5y ago
  It's not an energy source, it's a battery.

wyager 5y ago

There are several conceptual issues here, but one of them is that trees require energy from sunlight to turn CO2 into other things.

realusername 5y ago
Yes but we don't have an energy problem, we have a CO2 problem and there's no law of physics preventing to absorb more CO2 than you emit.
- diarrhea 5y ago
  That's true but assumes the captured CO2 remains that, captured. The article revolves around the idea of turning CO2 into fuel. Fuel which is burned, releasing that same CO2 again while having wasted a lot of intermediate energy. At best, that energy was renewable and would've been curtailed otherwise (hence wasted). Then you didn't "use energy" but it was still an utterly useless exercise. Now, if the carbon remains captured and the energy for capturing is renewable, we are in business. I'm not aware that is done on a meaningful scale yet though.

peteradio 5y ago

But thats not what this is. Fuel is intended to be consumed, seems like this is at best carbon neutral assuming totally neutral power source. Are our current power sources on average neutral or are they much more carbon positive?

realusername 5y ago
> But thats not what this is. Fuel is intended to be consumed, seems like this is at best carbon neutral assuming totally neutral power source Indeed, that's their goal, the issue is that currently we emit a lot so even making the fuel close to neutral (minus production inefficiencies) is already a huge progress. Going negative isn't for tomorrow unfortunately.

marginalia_nu 5y ago

The problem is that this requires reversing entropy. Turning CO2 into something that can burn into CO2 requires more energy than you get back while burning it, even in an optimal engine. This is true if humans reverse entropy or if trees do it.

realusername 5y ago
Economics are a different story yeah, there's no way to make carbone absorption economically possible without some carbon scheme designed by the country. They won't happen on their own that's for sure, that's where legislation should come in place.
DennisP 5y ago
It's not an energy source, it's a battery.