Tuesday, October 18, 2016

CO2 Into Ethanol

Argh. I'm not educated enough to know what the implications are for this process with "high Faradaic efficiency (63 % at −1.2 V vs RHE) and high selectivity (84 %) that operates in water and at ambient temperature and pressure".

On the one hand, I remember how thermal depolymerization (turkey guts into oil) didn't pan out. On the other hand, I remember that one reason WHY it didn't pan out was that it turned out to be more expensive than anticipated to get the turkey guts--they had hoped to get them for free, but it turns out that normally turkey guts are sold for animal feed, and when the oil-makers had to pay for it, that cut into their profit margins. Plus, they had some early problems with odor that gave them PR issues. Neither of these would be expected to be an issue with ethanol-from-CO2, although I imagine that producing sufficient concentrations of CO2 to make the process work could be an engineering challenge. Also, "ambient temperature and pressure" seems like a big deal to me and very good news.

Overall I'm cautiously optimistic. Using nuclear power to turn CO2 into ethanol seems like a win-win-win scenario--although you'd obviously have to compare it to the competing scenario of using nuclear power to turn water into hydrogen for fuel cells, since both scenarios are really just ways of distributing energy. But I assume the PR for CO2-into-ethanol would be much better, which could make things politically easier.

I don't think this is a silver bullet. I doubt that more than 20% of the world's auto fuel will be produced via this method even twenty years from now--I expect we'll still be pumping most of our fuel out of the ground. But it will be great if this is a mature technology at that point which is proven to work reliably and economically.

Pop-sci article: http://www.popularmechanics.com/science/green-tech/a23417/convert-co2-into-ethanol/ 
Link to actual paper: http://onlinelibrary.wiley.com/doi/10.1002/slct.201601169/full

-Max

--
If I esteem mankind to be in error, shall I bear them down? No. I will lift them up, and in their own way too, if I cannot persuade them my way is better; and I will not seek to compel any man to believe as I do, only by the force of reasoning, for truth will cut its own way.

"Thou shalt love thy wife with all thy heart, and shalt cleave unto her and none else."

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