r/science • u/Wagamaga • Aug 06 '20

Chemistry Turning carbon dioxide into liquid fuel. Scientists have discovered a new electrocatalyst that converts carbon dioxide (CO2) and water into ethanol with very high energy efficiency, high selectivity for the desired final product and low cost.

https://www.anl.gov/article/turning-carbon-dioxide-into-liquid-fuel
59.3k Upvotes

94% Upvoted

1.8k comments sorted by

View all comments

743

u/awitcheskid Aug 06 '20

So does this mean that we could potentially capture CO2 from the atmosphere and slow down climate change?

1

u/[deleted] Aug 06 '20 edited Aug 06 '20

yes. But the problem is the amount of energy it would require

Generally the reaction for the burning of any carbon-based fuel (gasoline, wood, natural gas, ethanol, all of them) is:

*CH2 + O2 => H2O + CO2

and plant photosynthesis is the inverse of this reaction.

The problem of chemically capturing CO2, e.g. into ethanol, is that it ultimately amounts to unburning that CO2, and for that you will need to give back any energy obtained from the original burn, and more. And generally, if we're going to unburn anything, we'd be better off not burning it in the first place—which makes unburning irrelevant. Though there are special cases, storage in particular