[rmcginnis]

The energy content of the gasoline is less than the energy used to make it (only 50-60% efficiency), but the CO2 released is the same as the CO2 used. So the energy efficiency is low, but the net CO2 emission is still zero.

[Zenbit_UX]

Is your device small enough that it could be placed to filter the exhaust emissions from a fuel burning car and reinsert the newly created gasoline into its fuel tank?

[shawabawa3]

powered by what? It would only make sense if there was a carbon free cheap power source you could use to charge it - if you just take it from the car battery you're wasting fuel as it's only ~50% efficient