Ethanol of synthesis by recycling CO2

[Jon1980]

Hello everybody
My old memories of chemistry tell me that we can produce ethanol from CO2 (captured on installations or vehicles) by magnesium synthesis by a reaction of this style:
CH3-Mg-Br + CO2 -> CH3COOH
CH3COOH ---- LiAl4, ether, H3O + -> CH3-CH2-OH.
I was wondering why we don't use this synthesis mode. Is it too expensive? too polluting? too low yield? difficult reaction to do because of the magnesian synthesis? reprocessing of recation waste? ...
If someone had an answer it would be cool.
Good end of aprem '.

[Christophe]

I will not put my hand in the fire but I think you have the answer:

too low yield? difficult reaction to do because of the magnesian synthesis?

I would have said it differently:

"If the CH3-Mg-Br costs econologically (ie gray energy + CO2) more expensive to produce than the advantage, on the same criteria, the use of ethanol compared to gasoline, l the interest of this daughter is negative "

It is the same problem as with the acetylene car that I discovered yesterday: https://www.econologie.com/forums/carburant- ... t6263.html

Here's a very comparison of CO2 gasoline ethanol

[Remundo]

Hi Jon,

Organomagnesium, here an organomagnesium bromide, are chemicals intended to produce almost all organic functions (alcohols, acids, etc ...).

They are expensive to produce and difficult to produce. They are not very stable either ...

This is not a time of massive fuel production.

The most promising way to obtain methanol is the combination with dihydrogen.
CO2 + 3H2 = CH3OH + H2O

But above all the transformation of Syngaz from biomass thermolysis
CO + 2H2 = CH3OH

In all cases, this requires heat and / or pressure, but it is playable with a mix of renewable energy finally developed at the height of its potential.

[Jon1980]

Thank you Christophe for taking the time to respond. Sometimes we ask ourselves strange questions. I'm going to take a look at the 2 links that you indicated to me.
Good end of aprem and thank you for your response.

[Christophe]

The most promising way to obtain methanol is the combination with dihydrogen.
CO2 + 3H2 = CH3OH + H2O

Ah yes but here it is methanol and not ethanol. j

It's just harder to use methanol than ethanol ...

The reaction you evoke could be "easily" used to liquefy laigret gas since it produces CO2 and H2 ... https://www.econologie.com/projet-laigre ... -3917.html

[Jon1980]

Thank you Remundo for the details you gave. I forgot a little all these stories of syntheses of magnesians but sometimes memories mix and we say: but why we do not do that? Then we reflect and we say to ourselves: if it was so simple why don't we do it that way? And finally we say to ourselves: we're going to ask the question to see why it's not going well.
Thank you. Good end of aprem '.

[Jon1980]

The reaction you evoke could be "easily" used to liquefy laigret gas since it produces CO2 and H2 ... https://www.econologie.com/projet-laigre ... -3917.html

Still reading !!! Please note I will be back soon with lots of questions

[Cuicui]

Hello everybody
My old memories of chemistry tell me that we can produce ethanol from CO2

Uh, isn't that what happens in nature: photosynthesis (by solar energy) then transformation of sugars into alcohol by yeasts?

[Jon1980]

Uh, isn't that what happens in nature: photosynthesis (by solar energy) then transformation of sugars into alcohol by yeasts?

Indeed, but I was thinking of another synthetic route that we master better than artificial photosynthesis ... Ok, I admit, I hadn't thought that I could bring my story closer to photosynthesis!
Bonne journée.