2 ms·
> Obviously, the efficiency of the cycle is lower when starting from air instead of from pure carbon dioxide, but the input energy is unlimited, as it comes fro
by leoedin 3y ago
> Obviously, the efficiency of the cycle is lower when starting from air instead of from pure carbon dioxide, but the input energy is unlimited, as it comes from solar or wind energy.
What sort of energy inputs are required for a kg of CO2? If the process is so inefficient that e-fuels contain only a few percent of the energy inputs, then it's pretty unlikely to be a good use of electricity (even excess renewable energy).
That's the pivotal number. kWh per kg of CO2. It needs to be reasonable.
Ultimately only 0.04% of the air is CO2. You need to process a lot of air to extract large amounts of CO2.
- adrian_b 3y agoIf you look through your window, it is likely that you will see the proof of concept that the energetic efficiency of extracting the 0.04% of CO2 from air and the hydrogen from water, and of converting both of them into hydrocarbons can be high enough to allow you to breathe and to satisfy your hunger. The artificial alternatives already have better efficiency for capturing the solar light and for extracting the hydrogen. It remains necessary to improve the efficiency of the CO2 capture and of the conversion to hydrocarbons.