Did they mention its use as a scrubber for things like coal fired power plants?
Brian
I'll try to explain it in a simple way.
C+O2 = CO2 generates 1 Energy.
CO2 + H2O = alcohol requires 3 energy.
A clearer way of putting it, is to to say that scrubbing CO
2 using a process like this would consume at least as much energy as was produced by the process that liberated CO
2. Add inefficiencies and you end up with a net energy loss.
To put some hard numbers on it:- Every megajoule of energy obtained from burning coal* liberates 2 mols of CO
2. Every megajoule of energy obtained from burning ethanol liberates 1.6 mols of CO
2 - a perfect process for making ethanol from CO
2 would use the same amount of energy. That is, you can only pack away 1.6 mols worth of CO
2 from coal with the energy liberated in creating 2 mols of CO
2. Thus you're already on the losing side of the energy equation before any process loses.
*The assumption used where I lifted the figures from is that the C:H ratio in the coal burned is 1:1 which is about right.