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So, we could take concentrated CO2 from a furnace, and instead of releasing it into the atmosphere directly, convert it to Methane, and then burn that increment

So, we could take concentrated CO2 from a furnace, and instead of releasing it into the atmosphere directly, convert it to Methane, and then burn that incrementally? Or could we possibly fit an exhaust-gas tank onto our engines that holds all the combustion products, and is collected and recycled at the gas station?

rocqua 3y ago
It's easy to capture at places that produce lots of CO2. Say fossil fuel electricity plants, and apparently also the production of Cement. Long term, these sources will hopefully dissapear. But short term, concentrated sources of CO2 are sadly still quite abundant. It would be cool if, long term, the CO2 released by burning this in home furnaces for heating can mostly be re-captured.
- modo_mario 3y ago
  >It's easy to capture at places that produce lots of CO2. Not easy enough apparently, the US gov started subsidizing/taxcutting this because there was demand for CO2 in enhanced oil recovery but the price was too high.
- XorNot 3y ago
  This doesn't work. You need energy to convert CO2 back into propane. The CO2 is coming from fossil fuels, which you're still ultimately going to burn again to get energy back...putting the CO2 back into the atmosphere. Only now you've thrown away some of the energy in losses doing the CO2 to propane conversion. This would lower the efficiency of a fossil fuel powerplant, and this increase the CO2 emitted overall.
  - malfist 3y ago
    Only if you use energy from fossil fuels to do the conversion. Earth's energy isn't a zero sum game, we have plenty of decarbonized energy sources.
  - rocqua 3y ago
    I meant to do the CO2 capture at gas furnaces in homes. Because the electric power available for heating is ofte limited, but might still be sufficient to gather CO2 from the exhaust of the furnace. It'll cost energy, but it is a cheap source of CO2 for this electrolysis.
    - XorNot 3y ago
      To convert CO2 back to propane you have to put in every bit of energy released when burning it and then some. So again, it wouldn't work because as you note: the electric power available is less than the gas.

rocqua 3y ago

It's easy to capture at places that produce lots of CO2. Say fossil fuel electricity plants, and apparently also the production of Cement. Long term, these sources will hopefully dissapear. But short term, concentrated sources of CO2 are sadly still quite abundant. It would be cool if, long term, the CO2 released by burning this in home furnaces for heating can mostly be re-captured.

modo_mario 3y ago
>It's easy to capture at places that produce lots of CO2. Not easy enough apparently, the US gov started subsidizing/taxcutting this because there was demand for CO2 in enhanced oil recovery but the price was too high.
XorNot 3y ago
This doesn't work. You need energy to convert CO2 back into propane. The CO2 is coming from fossil fuels, which you're still ultimately going to burn again to get energy back...putting the CO2 back into the atmosphere. Only now you've thrown away some of the energy in losses doing the CO2 to propane conversion. This would lower the efficiency of a fossil fuel powerplant, and this increase the CO2 emitted overall.
- malfist 3y ago
  Only if you use energy from fossil fuels to do the conversion. Earth's energy isn't a zero sum game, we have plenty of decarbonized energy sources.
- rocqua 3y ago
  I meant to do the CO2 capture at gas furnaces in homes. Because the electric power available for heating is ofte limited, but might still be sufficient to gather CO2 from the exhaust of the furnace. It'll cost energy, but it is a cheap source of CO2 for this electrolysis.
  - XorNot 3y ago
    To convert CO2 back to propane you have to put in every bit of energy released when burning it and then some. So again, it wouldn't work because as you note: the electric power available is less than the gas.