An even more egregious example is gas flaring. The extraction rate is not totally controllable, so there can be more pressure than the plant can handle. Currently, most plants just burn this gas without generating anything, because it would be prohibitively costly (compared to the return) to transport that electricity.
To the parent re: efficiency and economics, the supplemental info: https://pubs.acs.org/doi/10.1021/jacs.9b07310 (as a rule, free/open access w/ 90% of the utility of a given paper) has the half cell potential at about 0.6V[1] vs RHE, which puts a whole cell potential at about 2V. So count the electrons to convert CO2 to propanol, take Coulomb's constant to get amps, convert to watts, and do the stoichiometry to get kwh/tonne propanol.
This is all ignoring throughput and CAPEX utilization, which is almost certainly poor (but not unexpected at this stage of research).
It is also worth noting that they are using a 3 dimensional, convoluted electrode (carbon cloth) to support their catalyst which may be responsible for the claimed 'trapping of CO'-effect, rather than their specific catalyst. Notably C3's have been observed before in CO2 reduction from less involved catalysts.
tl;dr Probably not very efficient at all, I'm too lazy to do the math. If it was efficient, it would probably still be wildly uneconomic to make propanol via this route.
[0]per unit of production, revenue
[1]Don't forget to account for side product production, per the supplemental information they are making about 600 moles of H2 per mole of propanol (hard to read the chart).
It's non-negotiable. We have to do it. So the economics of it don't matter. We aren't wasting power. We're paying back a very large debt to the planet that we've been accruing for over a century.
Yes they do and saying they don't only hurts efforts with actual chances to succeed. Money isn't some made up thing, it is man-hours and resources, and spending people on feel-good technology keeps them from doing actual good to help the environment.
There are no ifs, ands or buts about it, we have to return the energy we borrowed and rebind the carbon in our atmosphere. It doesn't matter if thereisnospork doesn't see the utility in this, it doesn't change reality. So again, the energy is not being wasted. It's being used. Just because there isn't a net 0 expenditure doesn't mean it's a stupid idea, that sounds like a Conservative talking point waiting to happen.
I'm starting to think that the solution might be a "drilling/price moratorium" rather than a direct carbon price. Like OPEC but global.
And I don't see how gas flaring has bearing here. If it's not profitable to capture carbon fuel that's right there, in the form a widely traded energy source - why on earth would it be profitable to burn it, to power a generator, to extract CO2 from the air, to turn it back into carbon fuel? You just end up back where you started. Surely it's easier to simply build a plant that can handle higher pressure surges, and ship the gas as-is. But it's not profitable.